+++ #337 Subject: Marking Pens; Aviation Snips From: Russ Erb I've been doing some research lately with different marking technologies. The initial problem is that you can't use just anything to mark aluminum. One definite no-no is using pencil on aluminum. The carbon in the lead will cause corrosion to start in the aluminum. The common wisdom is to use Sharpie permanent markers. The markers with extra fine points make nice marks on aluminum, even on shiny, smooth Alclad sheets. If you try a water-based marker on AlClad, such as a marker for noverhead transparencies or washable kid's markers, it is pretty much useless. The ink does not adhere to the aluminum, but rather beads up on the shiny surface, much as drops of water would bead up. Removing the line is fairly easy, too. A paper towel and some isopropyl alcohol does the job nicely, which also takes off the ink markings from the manufacturer. Well, that works great on shiny, smooth surfaces. But what about matte surfaces, like the typical surface of a 6061 piece, a Scotch-Brited piece of 2024, an alodined piece, or a primed piece? In each of these cases, the permanent marker leaves a very nice line. However, this line is very difficult to remove, regardless of how much alcohol and elbow grease you use. It's as though the rag or paper towel can't get down in the microscopic "scratches" to wipe away the ink. I have also had cases where I thought I had fully cleaned away a marking, alodined the part, then primed it with Poly Fiber Metal Prime. The primer seemed to somehow reactivate what little remaining ink was there (so little you couldn't see it) such that ink came up through the primer and became visible again. This hasn't been a big problem so far with internal parts and even on the outside of the flaps and ailerons, since these parts will be fabric covered and part of the process is to apply an opaque layer to protect the fabric from UV radiation, hence no marks will be seen through the fabric. But what to do for the wings and other parts where marks showing through the finish would be very unsightly? On a whim, I decided to try that which didn't work before. Specifically, to try a water-based marker. I tried it on Alclad aluminum. Sure enough, it still doesn't work. I Scotch-brited a piece of Alclad aluminum and tried the marker--it worked acceptably. I tried a piece of alodined aluminum--it worked acceptably. I tried a piece of primed aluminum--again it worked acceptably. Somehow the microscopic "scratches" allows the ink to grip the material better without beading up, much like paint. For each case, the ink was easily and completely removeable with water and a paper towel. The downside is that the ink line is much less durable than the permanent ink line, meaning that rubbing your hand or anything over the line can easily smudge it or even erase it. If you're careful not to touch the line, though, it will work plenty good enough. Therefore, my recommendation for now is: 1. On shiny Alclad aluminum (usually 2024), use the permanent marker and clean it off with isopropyl alcohol. 2. On matte finishes, such as 6061, scotch-brited sections, alodined pieces, and primed pieces, use the water-based (washable) marker and clean it off with water. Be careful not to smudge away the line. ********************************************************************** "And now for something completely different..." A few notes on the use of aviation snips (or "tin snips"). I'm not sure why this doesn't appear in the typical homebuilder's books: First, get a right hand and left hand version of OFFSET (or "Duckbill") snips. Usually these have red and green handles. The left and right hand refers to which direction of curve that the snips will cut, not which hand you hold them in. The left and right hand snips are mirror images of each other. Why each one will cut curves in only one direction is tough to explain, but fairly obvious after using them. Don't waste your money on the non-offset snips. The offset allows you to cut for any distance across a sheet without excessive bending of the sheet. Try that with non-offset snips and the sheet will run right into the pivot bolt. I have not found anything yet that could be done by an non-offset snip that couldn't be done by an offset snip. To use the snips, do not cut right to the line on the first cut. Doing so may be very difficult and lead to distorted parts. Instead, rough cut to within about 1/8" of the desired line. Then go back and finish cut to the desired line. Doing this will let the thin piece of scrap bend out of the way while leaving the part undistorted. Additionally, the scrap doesn't get in the way of cutting curves. Be prepared to swap back and forth between the left and right handed snips as required. In general, use the one that works for the current cut. If it's not working, try the other one. At least one of the jaws of the snips typically will have small serrations on it. Presumably these serrations keep the snips from slipping while cutting. Unfortunately, these serrations will leave marks on the parts. You'll want to scotch-brite these marks out to remove the stress concentrations, just like you would for any other scratch. I have not tried grinding the serrations off of the snips to see what effect it would have. +++ #338 Subject: Re: Marking Pens; Aviation Snips From: Bruce A. Frank I lay out and weld aluminum projects every day. Most finished projects are anodized, powder coated, or alodyned and spray painted. We use the really fine point Sharpie permanent markers to layout and the heavier markers to show part numbers and other information. Before the parts go to the final finish every thing is wiped down with acetone. Acetone removes all traces of the marker and there are no show or bleed throughs of the final finish. The most stubborn thing to remove is the glue from the strapping tape used by the shipper. This is best removed with mineral sprits followed by acetone. I have never heard of the carbon in a pencil causing corrosion of aluminum. Maybe something in the binder? What is your source of information about this problem? I have sooted pieces of aluminum in my shop, cut from pieces that were going to be annealed, that have been hanging there for years. No evidence of corrosion. I have stacks of sheet material (2024,6061, & 5053) with the alloy marked in pencil and I have seen no sign of corrosion. The pencil line can be buffed off with a cloth or wiped off with acetone. +++ #340 Subject: Re: Marking Pens; Aviation Snips From: bearhwk27- 1. For marking on "stuff" search out and try a "Grease" pencil. Good art supply store will have them. Just sharpen with a pencil sharpener. Will wipe off with rag or several solvents. To make a mark last for a long time reference mark just cover it with a small piece of clear tape "Scotch"tape. 2. If you take the serration's off your snips they will not cut and track as well and you will wish you had not modified them. +++ #341 Subject: Re: Marking Pens, Pencils are a no no. From: bearhwk27- With respect to pencils... I guess that the most recent relearn of this issue was with the cracks in the C5A wing. Many of the stress cracks propagated from areas that had pencil marking. The culprit is the graphite in the pencil lead reacting with moisture. You will not see the problem with your naked eye and the application of load to a piece accelerates the action. +++ #344 Subject: Re: Marking Pens, Pencils are a no no. From: Todd Chisum For parts where you don't want to leave marks, try laying a strip of Scotch tape (like in your desk top tape holder), then marking on the tape with a pencil, pen or ??. After you cut, you can peel the tape off. Scotch makes a version of this tape that peels off very easy with no residue left behind. Does the ink in the Sharpie pens cause corrosion if not removed? +++ #345 Subject: Re: markers From: Rodney Smith While on the subject of markers, I have read a couple of places that a silver pencil is good for marking steel. I bought a couple and found that the marks were hard to see and very easy to remove just by smudging with your thumb. Get a little cutting oil on the mark and it disappears immeadiately. I therefore have been using sharpie markers for marking steel parts and that has worked out a lot better. The sharpie ink is a little more resistant to the cutting oil also. For what it is worth I have seen the same warning about using pencils on aluminum more than once in print. Also to further confuse things, at our plant it is a definite no-no to mark stainless steel piping with ink markers. The ink supposedly corrodes the stainless steel over time. +++ #355 Subject: Re: Results: Ink removal experiment From: Bruce A. Frank I understand your reluctance to expose yourself to solvents, but acetone's impact on the body is little different than alcohol. It is one of those substances that our body makes a little bit of, so it is in our systems in trace quantities. That being said, one can still become sensitized to it and react to it with headaches and upset stomachs. It is a pretty good general cleaning solvent with few of the really bad side effects of such as Toluol or MEK. +++ #513 Subject: EAA Chapter 1000 Standard Work Tables From: Rod Smith The last few weeks of my time off I have been busy building work tables. Up to now I have been doing all my building at my work location. Now I will be starting to build the wings at home so I will be attacking this project on two fronts so to speak. I have a large garage but I needed to get it organized and some work tables built. I have built four tables pretty much to plans as found at : http://www.eaa1000.av.org/technicl/worktabl/worktabl.htm. These are a very well designed, very sturdy table 2 x 5' in dimension. You can bolt them together to make larger tables as necessary. I built one of them 4' wide. I will mount a roll of aluminum on the end of this and do my layout and cutting for ribs on this table. It will be away from the wall for access to both sides. The other three tables are laid out in a L around one corner of my garage. I will mount my drill press between the two on one wall and this will provide a large enough area to fabricate the wing spars. My hat goes off to Russ and the rest of the Chapter 1000 gang. Check it out. +++ #519 Subject: Screw Levelers From: Russ Erb I didn't bother with levelers, partially because I didn't want to bother, and partially because it forces all of the load through such a small area (I like the whole leg resting on the support). My garage floor is far from level, so this is an issue. I just shim up the appropriate legs with pieces of plywood and aluminum shims (the waste from lightening holes works well). +++ #529 Subject: Re: EAA Chapter 1000 Standard Work Tables From: Todd Chisum >Do you or others use the screw levelers for the legs and if so where do >you source them. You can get what is called "elevator bolts" to level tables with. They should be available at any fastener supplier, maybe not a hardware store though. Something I have used on work tables is to drill a hole in the bottom end of the leg, insert a 5/16-20(?) Tee nut and use a 5/16-20 carriage bolt for a level adjustment, if you can find 3/8 or 1/2 tee nuts and carriage bolts that would be even better. You will also need the Tee nuts for the elevator bolts. The elevator bolts have a large, flat head and a grip area like a carriage bolt for adjustment. McMaster-Carr also sells the elevator bolts. +++ #531 Subject: 2nd airplane From: gdanfor- In building the Hatz, I found a sand blaster most handy and you can build your own easily. Best source for parts is "TIPTOOLS.com". They have plans and every thing you need to build a very inexpensive blaster. +++ #602 Subject: Re: Interested builder From: Float-by Shooter > and while not a pro I can get two pieces to stick together. By the way > are you guys using the tubing notchers, I've seen these tools > advertised and wondered if they work? My impression is that most of us here on the list have not yet reached the point where a tubing notcher would be practical (ie the fuselage). I've read various opinions on them in the course of my research, and most people seem to either love them or hate them. I know that on this forum we have at least one of each and you will probably get both of their opinions. My EAA "Aircraft Welding" book shows what has to be the slickest way to notch tubing, use a lathe with a large reamer chucked in it, and a fixture to hold the tubing steady as you feed it into the reamer. Of course the problem for most of us is no lathe... +++ #604 Subject: Re: Interested builder From: budd davisson Re: Tubing notchers Everyone has their own style of putting tubing together and y ou'll develop yours. Don't get so caught up with gadgetry, however, that it slows the project. You may find you spend more time setting up a tubing cutter (if you're talking about the kind that is a hole-saw in a drill press) to get the angle just right than it is worth. Another problem is you have to have the length measurement exactly right. By grinding, you can start a little long and gradually shorten it to get exact fits. A tried and true method is to dress the edge of a grinding wheel to the diameter of the tubing being joined. that works really well and is fast. Some of us just leave the edges of the wheel square and use the edge to "wipe" the radius in. That happens in nothing flat. I once started timing how fast I did different operations and found I could fit a vertical in 14 minutes and a diagonal in 18. Guys that really know what they are doing are probably much faster. Knowing those times, I could duck out while waiting for dinner and get something accomplished. A quick hint: don't mount your grinder on the bench. Make a movable base for it (I use an old kitchen base cabinet that's only a foot wide and put wheels on the back edge), so you can always have it right at your elbow where you're working. Otherwise you waste too much time walking back and forth to the grinder. The beauty of gas welding is the bead is always so much wider than the thickness of the metal that it bridges and melts irregular edges really well. Although smooth pretty edges are nice, they aren't necessary so long as the gaps don't get ridiculous and the weld puddle has good penetration. Just the reverse is true on fittings however. There, the prettier, the smoother the edges the better. +++ #606 Subject: New member From: Mike Guthrie I have been reading your postings since coming from Bob's builbers diner, talk about being reinspired. Back in the shop for the winter. A coment on tube notching you can get small sanding drums for your die grinder that fit the size of the tube your fitting, I tryed these for practice welding with good results. The ligihtng holes in the spars are they flanged? +++ #611 Subject: Tube Notchers From: Tim Went down to the basement and grabbed mine, for a closer look. Dean/me purchased two from Harbour Freight Tools, last July while on Sale. Think they were was $35.00ea...yeah, thats why we bought one each....This notcher is probably a copyright rip-off/spin-off of the 'Ole Joint Jigger' or one of those notchers you see in the back of Sport Aviation. But the difference being, this knockoff is made in CHINA....Bottom Line is surprising...High Quality with a very good finish for CH-CH- China.....I avoid tools from there, Canada does big trade with the Commies and we see a lot of Shizen coming out of there...kinda like the early 60's and JA-PAN......How does it Work?????? Haven't a bloody clue, as I have yet to call Charlie at Dillsburg Aeroplane Works for 4130 tube. This coming summer I plan to tackle my fuselage....Wouldn't wanna shock cool those cluster welds with a cool Canadian Winter ;-) +++# 627 Subject: Tubing Notchers and other metal working tools From: Russ Erb Okay, I'm finally ready to weigh in on this one. >Everyone has their own style of putting tubing together and y ou'll >develop yours. Don't get so caught up with gadgetry, however, that it >slows the project. I understand what Budd was saying here, but I feel compelled to say that there are times that "gadgetry" is a good thing. I'm currently assembling my first wing, after completing the flaps and ailerons. Some of you may have thought me over-doing it when I built very precise jigs to route out all of the ribs to their precise sizes. Sure, it took extra time to make the tooling, but I could also claim that I was able to cut out the rib blanks faster than I would have one at a time with tin snips. Definitely more accurately and precisely. The payoff has been that the fit up of the ribs has been incredibly easy. Almost plop it up there, and it's in the right position. Kind of like the old Fram commercial--you can spend the time now, or you can spend it later. There are times that good tooling is worth the effort. As a friend of mine says, "The reason we build airplanes is so that we have a reason to buy all sorts of cool tools!" Reference the horizontal/vertical bandsaw: >You'll never use it as a horizontal cut-off saw because it is unnecessary.< I heartily and respectfully disagree! I've used it this was as much or more than I've used it vertically. This is my favorite mode, in fact. You clamp in the tube (or whatever) in place, turn the saw on, and walk away. This is the part I like--when it's done, it automatically turns itself off! My preference is, when possible, let the technology make the cut accurate rather than the art of handling the piece. As for the tubing notcher, I have one of the Harbor Freight versions. I've used it some, but not much because it only works down to diameters of about 3/4", and most parts on the wing steel are smaller than that. For those, I used the grinding wheel to shape the parts. Following is an article which I have written for the Bearhawk Reference CD (available sometime hopefully in 2000) and the EAA Chapter 1000 newsletter. It contains my experiences and opinions on several metalworking tools. The pictures aren't included in this e-mail. *********************************************************************** Notes on Steel Working Tools It probably comes as no surprise to you that having the proper tools for a job makes the job much easier. Perhaps this is why we tend to accumulate tools so quickly. I haven't checked lately, but I wouldn't be surprised if my tool expenditures are still ahead of my material expenditures. Growing up, I was exposed to two primary building materials: wood and steel. I found wood very easy to work with, but steel was very difficult and I came to avoid it whenever possible. Looking back, I can see that the primary reason I didn't like working with steel was that my Dad's shop was not well equipped with tools for that purpose (while it was equipped for wood working). I seem to remember having a hack saw, tin snips, and a file or two. Not exactly what you would want to start building an airplane with, unless you have an unnatural aversion to power tools. So naturally this childhood aversion would drive me to build an airplane with a steel tube fuselage and tail, right? Actually it was more of a case of ignoring those childhood memories and figuring that a few good power tools would help. Sure enough, with a better set of tools, steel was significantly easier to work with. The tools that I use most for steel are a horizontal/vertical metal cutting bandsaw, a 1 inch belt sander, a grinder (same one that has the Scotch Brite wheel for aluminum on the other side), a Moto-Tool with a 1/2" grinding wheel and a fiberglass cut-off wheel, a 3" metal shear, a tubing notcher, and the usual assortment of drills and files. Of course there's some sort of welding equipment for putting together the stuff you've cut apart, but I'll save that discussion for a different article. Horizontal/Vertical Metal Cutting Bandsaw Harbor Freight http://www.harborfreight.com/ Item 37151 $179.99 This bandsaw uses 1/2" x 64-1/2" blades, which are available with either 10 teeth per inch (tpi) or 18 tpi. For aluminum bar stock, I've found that the 10 tpi blade works best. Using an 18 tpi blade results in the aluminum shavings sticking in the teeth and thus clogging up the blade to the point that it doesn't cut anymore. With the 10 tpi blade, the shavings fall out properly. For steel, I normally use the 18 tpi blade for steel. By adjusting a belt on pulleys, the saw can be run at three different speeds. Guidance is given on selecting speeds, but typically I just run it on the slowest speed with adequate results. In the vertical position, it can be used like a conventional bandsaw, feeding the stock through by hand. This is the best position for "ripping." Cuts can be made to any length for a width on the inside up to 2-3/4 inches wide. Because of the 1/2" width of the blade, cuts are mostly limited to straight cuts. When using the saw in the vertical position, the best way to keep the saw from falling over or scooting across the floor is to sit on the base portion like you would sit on a horse. The only odd thing about this, other than making sure the vise is out of the way, is that it puts the power switch under your "hinders." For "cross cutting," it is far more convenient to use the saw in the horizontal position. In this case, you secure the workpiece in the vise, lower the saw blade onto it, turn the power on, and walk away to do something else. The cool part of this design is that it will work away at sawing through the piece, feeding itself by gravity, then shut itself off when it is done! To use the saw in the vertical mode, a work table is provided. However, this table must be removed to use the saw in the horizontal position because of interference. It has been shown that the table can be cut down in such a way that there is no interference, yet still be useable in the vertical position. 1" Belt Sander I use a 1"x30" belt sander from Sears. It gives you about 4-1/2 inches of working space. There are also 1"x42" belt sanders (shown here) available. I found out about the bigger size after I had bought mine, but I have not been constrained significantly by the shorter working area. My belt sander has a 5 inch disk sander on the other end of the motor, which I have pretty much never used. I don't care much for disk sanders because they remove material unevenly. This is mostly because the tangential velocity of the sanding medium increases as you get further from the center. (If you have an application where a disk sander is better than a belt sander, I'd love to hear it!) I first thought it would be more useful to have a wider belt, such as a 3" or 4" belt like woodworkers use. Even so, I bought the 1" wide belt sander because 1) it's what "everybody" said to use, and 2) it was less expensive. As it turns out, it has been quite satisfactory for virtually everything I've needed to do. I think the difference comes from where wood is typically "wide" (3/4" or greater), steel is typically "thin" (under 1/8"). For doing edges and convex curves, the 1" belt is plenty wide. On the rare occasion that I need something wider or close into an acute corner, I clamp my handheld 3" wide belt sander upside down on the work table. The belts are available at Harbor Freight in 80 grit and 120 grit. Buy them in the 5 pack package, which is dirt cheap compared to buying them individually at Sears. I have found these belts to be of good quality, and they last significantly longer than I would have expected. I recommend that you use different belts for sanding steel and aluminum. That way you won't get little bits of aluminum embedded in your steel or, worse yet, little bits of steel embedded in your aluminum. Dissimilar metal corrosion, you know. Same reason you don't use steel wool on aluminum. Grinder I use a basic bench grinder, again from Sears. I decided on the 6" grinder after long and exhaustive research (specifically, I opened the Avery catalog and determined that their Scotch Brite wheels are 6" in diameter). Grinders are similar to table saws, in that they come with guards that people tend to take off and not use. Now I'm all for safety, but there are times when safety devices get in the way and make the job less safe, or prevent the job from getting done. I bring this up because I use the guard over the grinding wheel but not over the Scotch Brite wheel. This was for two reasons. First,some of the aluminum parts I used the Scotch Brite wheel on are long enough that the guard would be in the way. Second, a Scotch Brite wheel is typically used differently than a grinding wheel. The workpiece is placed on the part of the grinding wheel that is turning toward you, whereas the workpiece is placed on the part of the Scotch Brite wheel that is turning away from you. Since the guard is designed for grinding wheel use, it would cover the part of the Scotch Brite wheel that you need to use. My guard came with a yellow plastic piece that holds a light bulb and supposedly serves as eye protection. Because of its color, I find it makes the part more difficult to see. I usually just move it out of the way and use goggles or safety glasses. Moto-Tool Another extremely useful tool is a Dremel Moto-Tool or one of the many look-a-likes. Of course, this tool does just about everything but hammer, but there are two uses that I am inerested in for this discussion. With a 1/2" grinding wheel, this tool is useful for grinding all of those inside curves that none of these other tools (except some files) can get to. The other use is with the fiberglass cutting wheel. This will cut in many areas that no other tool will get to. Be sure to get the cutting wheel made of fiberglass. The emory cutting wheels may be cheaper, but they have a MTBF on the order of seconds. 3" Bench Metal Shear Harbor Freight http://www.harborfreight.com/ Item 32153 $49.99 You may have seen a 4 foot or larger shear, which is very nice for cutting thin sheets of aluminum in one motion. The drawback of these shears is that they don't have sufficient capacity for steel in thicknesses larger than about 0.032. Enter the 3 inch bench metal shear. While the 4 foot shear cuts like a paper cutter, the 3 inch shear cuts more like a pair of scissors. Don't be fooled by the 3 inch dimension--the body of the shear is slotted such that straight cuts of any length can be made. It is also useful for trimming convex curves down to about 3/4 inch diameter. The shear capacity is quoted as 12 gauge steel, which is a thickness of 0.1072 inch. I have demonstrated its capability to cut 0.100 4130 steel. Mike Meador has cut up to 0.125 4130 steel, but says you don't want to feed it a steady diet of such thick material. An adjustable stop keeps the stock from twisting between the cutters, which is required to allow the cutters to do their job. This stop is a little less than 3/4 inch from the cutter, which means that the material on this side of the cut line has to be 3/4 inch wide or greater for the shear to work. The handle for the shear is not permanantly attached, but rather fits on a hex head like a box end wrench. You could conceivably use a wrench or socket instead, but the supplied handle seems sufficient for as thick of material as the cutters can handle. I did find that the handle tends to work itself off of the hex head with continued use--this could be quite a surprise if it came off while cutting! The simple solution is to remember to push it back on before each cut. Rather than mount the shear directly to a work bench, I mounted it on a 2 foot 2x4 with counterbored carriage bolts. This 2x4 was then set across the short dimension of a EAA Chapter 1000 standard work table and held on with bar clamps. For cutting the thicker pieces, the best technique I found was to hold the handle with my arm fully extended, step up on lower shelf, and then lean back, thus using gravity to supply the force to cut instead of muscles. When making a cut longer than 3 inches, it is critical to remember what you learned in kindergarten about using scissors. That is, don't cut all the way to the end of the blade. Stop before the end of the cutter gets to the sheet and reposition the sheet. If you don't, the sheet will be distorted as the cutter continues to shear but the sheet immediately past the end of the blade is not sheared. Try it with scissors and paper (no rocks required) and you will see the same result. (It appears Harbor Freight may have discontinued this item. However, they still carry other similar items.) Tubing Notcher This is the doofus that holds your tubing at a particular angle and then uses a hole saw to cut the fishmouth end for a "perfect" fit. The most advertised version of these is the Ol' Joint Jigger (http://www.jointjigger.com/, $165). Their ad will lead you to believe that any other tubing notcher is inferior. This may be true, but it doesn't mean the others are inadequate. I use one from Harbor Freight (Central Machinery, Harbor Freight Item 35782, $60) which cost significantly less. I've used it several times and haven't had any trouble. Don't try to save even more money by just using a hole saw from the hardware store mounted on a 1/4" bit--it won't work (I tried it). Since the hole saw is cutting the tube without the stabilizing presence of the center drill bit, the mandrel requires a lot of stability against side forces. The tubing notcher uses a long, heavy bearing shaft to provide this stability. This shaft slides in plain bearings, and should be oiled during use and kept clean from dust and shavings. The tubing notcher uses bimetal hole saws that are available at many sources, including your local Home Base or Home Depot. These hole saws screw on the mandrel with either 1/2 inch or 5/8 inch threads. The tubing clamp can hold tubes up to 2 inches in diameter. I was able to get hole saws at Home Base in diameters from 3/4 inch to 1-1/2 inches, and have seen hole saws available up to 2 inches in diameter. The minimum practical length of tubing that can be notched is around 4 to 5 inches because of the location of the tubing clamp. When cutting, be sure to use plenty of cutting oil. Don't try to use motor oil--it doesn't have the same properties. A good cutting oil is available from Avery (Rapid Tap Cutting Fluid, 4 oz., #7016, $3.50). Be sure to feed the saw slowly and lightly into the part. The tooth on the hole saw is generally excessively large compared to the thickness of the tubing. As such, if it is fed too fast and with too much pressure, the tooth can be forced to take too large of bite which will result in breaking the tooth. Drill Bits A discussion of drill bits could fill a book. In short, I recommend using cobalt bits with 135 degree split points for drilling aluminum and especially steel. High speed steel bits dull too quickly. The 135 degree split points reduce "walking" by the drill when starting a hole. Using cutting oil also speeds the drilling process and helps the bits last longer. Cobalt drill bits are available in number sizes and fractional sizes from Avery. Home Base also has cobalt drills in some fractional sizes. I am told that titanium nitride drill bits are even better than cobalt drills. I have not tried any, so I can't say. I have seen titanium nitride drill bits in fractional sizes available at Home Base. Files Some operations still have to be done by hand, and for that you'll need a set of files. I'd recommend that you have at least one "normal" size mill bastard (yes, that's what it's called) file, available at your local hardware store, and a set of specialty files like Avery's Swiss Pattern Needle File set (12 pieces, #475, $22, or 6 pieces, #476, $11.50). In Summary... I have since found that if you have some appropriate tools, steel not that difficult to work with. In fact, the belt sander and grinder look pretty cool when making a big shower of sparks--you feel like you are really doing something. However, you'll want a good pair of leather gloves as the parts do get hot! +++ #674 Subject: Flute plier results From: Jenni Thatch I have composed up in my mind that a taper pin (i.e cone shaped) would work even better than a cylindrical pin. I have at my disposition the equipment to make such a tool but I am curious about your results using the ones Bob has in Beartracks? This topic has probably been taken up before so if you know where I can research it I would appreciate your input. Thanks in advance!! +++ #675 Subject: Re: Flute plier From: csisters- in response to your inquiry about the fluting pliers the ones in the news letter work excellent. Except for the end of the nose ribs it takes very little fluting to straighting the ribs.Dont try to reinvent the wheel JUST FLUTE IT. +++ #681 Subject: Re: Flute plier From: Gary Danford Flute Pliers made from a pair of Vice Grips work excellent and you can easily adjust the amount of pressure. I bought mine from Aircraft Tool but i'm sure you can make a set easily. +++ #684 Subject: Re: Flute plier results From: bearhwk27- The fluting pliers sold by Aircraft Tools utilizing vise grip handles are great ! More leverage = easy to use. Adjustable crimp pressure= fast consistent crimp. If you try to do a conical tool the vise grip pliers will be mandatory, it takes a lot of force to do a conical flute. +++ #685 Subject: Re: Flute plier results From: Float-by Shooter > The fluting pliers sold by Aircraft Tools utilizing vise grip handles > are great ! More leverage = easy to use. Adjustable crimp pressure= > fast consistent crimp. If you try to do a conical tool the vise grip > pliers will be mandatory, it takes a lot of force to do a conical > flute. Since everybody is plugging their favorite fluting pliers, I bought one from Avery Tools which makes very narrow, good looking flutes. It is a non vise grip type, but it has extra long handles to give the required leverage. +++ #686 Subject: Re: Flute plier results From: Bill Cox I have several pairs of homemade fluting pliers similar to those shown in the newsletter that have served me well for the past 30 years. A couple of years ago I saw the ones that Avery sells and bought a pair. They make the best flutes of any I've used including the ones made from vise grips. I started out with the visegrip type in the early sixties and only used them for a few months until I was shown the homemade ones similar to the newsletter. +++ #793 Subject: metal shear From: Float-by Shooter I just thought I would share some information with y'all about a metal shear that I bought, which I don't remember having mentioned before. I bought it to help with the bodywork project I am currently mired in, for trimming patch panels and reinforcements. I needed a shear because my air shears broke and I was interested in getting a bench shear. I wanted to get a nice beverly shear but the cost was too much to justify, which I am now thankful for. Instead I bought a rolling shear which is made by Sykes-Pickevant and isn't nearly as bulky or heavy as the Beverly (though probably not as powerful). It has 2 rolling blades, one of which is operated by a simple racheting mechanism, and has small serrations which grip the metal and pull it through the shears. The serrations don't seem to mess up the edge any worse than my tin snips so they should clean up well with a scotchbrite wheel. Last week I used it to shear a couple of 6-7 foot lengths of .040 2024t-3 to repair a delivery truck box (not the ideal alloy, but it was there and we didn't really need it for anything else) and it worked perfectly with another person helping me feed it through. So far I've only used it on straight cuts but it can handle gentle curves, which may be of use to those of you still working on ribs. I'm going to use it when I get around to cutting out my spar webs, but I don't plan on putting any 4130 through it. I bought mine from the eastwood company for 89.99, part number 28034. http://www.eastwoodco.com/ No relationship except as a satisfied customer. +++ #1135 Subject: Re: Tex-Montana Express From: Float-By Shooter > them but It was what I could find and afford at the time. I have a > five hourse direct drive air compressor. I have a pneumatic jitterbug > sander and pneumatic sander and paint gun from body work days. I have You are extremely fortunate to have an air compressor. I don't think the sanders will be of much use to you but you will eventually need the paint gun. > The tools on my list would be a gas welder, metal brake, and??? What kind of metal brake did you have in mind? Any good quality bending brake is expensive (new), and an 8 footer capable of bending the spar webs is totally out of the price range of most builders. Some of us have managed to fabricate our own bending tools for some of the smaller parts (check the FAQ), but that only goes so far. I think that a good 4 foot brake would be great for a lot of the other stuff like the .032 4130, fuel tanks, etc, but then you run into the same problem again, cost. A new US made 4 foot pan and box brake (16 ga. capacity) runs around $1200 new. I might be able to scrape together enough (I will use it enough on other projects that it would be worthwhile), but unless I can find a good deal on a used one I will probably end up making my own. I have a book which gives instructions for making a 5 foot straight brake supposedly of 12 guage capacity, but you would need access to an arc welder of some kind to build it. > Do you attach the scotch-brite wheels to a bench grinder? That is what most people do. I have mine on a purpose built buffing motor which gives better access around the wheel, but it was something I already had and wouldn't have bought strictly for the scotchbrite wheel. > What tools are needed for the riviting? Either a rivet gun or a squeezer. The squeezer is quieter and probably easier to use, but very limited in what you can reach with it. The rivet gun will do just about everything but takes more practice to get it right. If you can only afford one, get the rivet gun, in the 3X size. > I am guessing that you use a band saw to cut > up the metal? A bandsaw is great for the 4130 steel and the thicker aluminum parts. You will need something else for the thin aluminum sheet. What you use to cut your ribs and spars is more a matter of personal preference, some have used routers and special templates, while a lot of us (including myself) have been perfectly happy with offset tin snips. One thing which would definitely make your life easier is a small air shears (since you have a compressor already), use it to rough out your rib blanks from the sheets, and finish trim with your snips or router. Other air tools which can be had reasonably that might help are a cut off tool and die grinder, but you won't need those until you start working with 4130. +++ #1175 Subject: router for aluminum From: Alan Nauman I have a 2 hp Ryobi router. I have it mounted in a custom router table. What type or bits do you use to trim or cut the aluminum parts with a router? I always thought it would only work on wood. +++ #1179 Subject: re router for alum From: stephan pelgar there are bits made for cutting alum with a router.there like a end mill with a slight taper and a quick cut flute.i know that ats(aircraft tool and supply) company sells them.i think there like 10 bucks a piece.as for regular bits im not really sure if they will work.hope this helps +++ #1181 Subject: Re: router for aluminum From: Float-By Shooter > I have a 2 hp Ryobi router. I have it mounted in a custom router > table. What type or bits do you use to trim or cut the aluminum parts > with a router? I always thought it would only work on wood. When I tried it, I used a laminate trim bit (the kind with a ball bearing on the bottom) and a template cut to the size of the rib blank. It worked OK, but was extremely noisy and threw little bits of aluminum all over the place. Might not be a problem for you, but my work area is such that cleaning them all up was extremely difficult. Russ' CD has some good pictures of templates for this method. +++ #1183 Subject: Re: router for aluminum(YES!) From: Bruce A. Frank Wood bits work as well or better on aluminum. I spray my bits with a little WD-40 to help prevent the aluminum from sticking as it will sometimes (you can carefully pop it off with a screw driver). Also the wax that you use on saw blades will help the chips clear from the router bit more easily. The table saw does an excellent job of cutting aluminum. In the metal shop where I work part time (needed access to the tools I don't have yet to build my plane)all of our sheet aluminum, over about 1/16th inch, is cut on the table saw. All of the aluminum we cut to shape, like ovals and circles and stencils is rough shaped with the plasma torch the brought to final spec with a router using regular wood bits. Carbide bits hold their edge longer but that's important only if you are cutting aluminum day after day. +++ #1192 Subject: Re: router for aluminum From: Tom Kennedy Try a one piece solid carbide bit used to flush trim laminates. These do not have a bearing and will come in two basic versions- one will give you a flush 90* trim the other has a 7* bevel towards the top. Either one of these bits will take out less material that a flush laminate trim bit with a bearing guide would. The 7* bevel would be my choice because it takes out even less material than the 90* bit. With a template there is no need for a table to rough cut your rib blanks. Might be able to use the table as a mill to insure uniform flange width after forming rib. Both bits go for about 5-6 dollars a piece at: http://www.grizzlyimports.com/products/index.html PS I took back my 2 HP Craftsman (Ryobi) router to Sears for a refund last Sunday. The shaft lock was always jamming and the locale repair shop said this was a common problem. Got me a 2 HP Bosch! +++ #1193 Subject: Re: router for aluminum From: bearhwk27- I have routed everything using a standard 4 flute Titianium coated carbide end mill. These are available from most machine tool supply houses at about $ 11.00 a crack. I have only used 1 for the project this far. The coating on the cutter keeps from loading up the 2024 material. +++ #1197 Subject: Re: router for aluminum From: george velguth A few questions about your aluminum routing experience: 1. When you say you routed "everything" do you mean all aluminum parts, or ribs only? 2. How close did you route to finished size, and how did you clean up/trim to finished size after routing. 3. Did you find it best to overcut or undercut while routing aluminum? +++ #1212 Subject: Re: router for aluminum From: bearhwk27- I routed everything to size and finished dimension. Router templates were made out of 1/2 thick high density particle board that had the exact contour needed. The aluminum to be cut was sandwiched between the template on top and a backer board below. Dowel pins located and retained the templates and aluminum. The end mill cutter has a smooth shank that followed the contour of the template. Parafin wax was rubbed on the template and aluminum surface for lubrication. Very little cleanup of the cut was required and most were burr free. Final detailing was via 320 sandpaper. Ribs,Spar webs,Capstrips, Fueltanks have been routed. Hooked the router up to my shop vac and kept the chips to a minimum. Fast, accurate, noisy. I would not use a standard router bit or laminate bit. To rough and coarse. +++ #1214 Subject: Re: router for aluminum From: Russ Erb > I would not use a standard router bit or laminate bit. To rough and > coarse. To express an alternate opinion--I used the carbide bearinged laminate bit. I thought the resulting edges were sufficiently smooth, especially compared with everything else I could have used. They weren't perfectly smooth, but were ready to go straight to the scotch brite wheel, which smoothed everything up just fine. I like the idea of a bearing rolling on the pattern better than a spinning shank--no wax required--but that's my opinion. I think either method will do just fine. +++ #1217 Subject: Re: Tex-Montana Express From: pfflyer- Concerning, the Racers Guide to Fabricating Shop Equipment, I bought one from Amazon a couple of weeks ago. Don't remember the price, but it arrived within a few days. There are well written plans for a hydraulic press, engine stand, rotiserie (for welding up the fuselage), cherry picker and automated cutting torch. Already built my own hydraulic press but not sure if I want to spend the time building the brake. Have access to an 8' brake, but it is challenged trying to bend the 1/8 flange on the 4130 channels. If I knew it would do a good job on those pieces, I would build it, but then I wouldn't have access to the other fellows shear. Nothing is ever simple. +++ #1228 Subject: Re: router for aluminum(YES!) From: Stephen Wolfe Don't know about routing aluminum yet, but I did find a great lubricant. It's called "B'LASTER", and is available at auto stores and Meijer's. Has all sorts of estoric claims on the label, and so far, all of them I tried have worked. Good for cleaning your guns, also. ( In case you want to take a liberal to the range to show him what he's been missing) +++ #1267 Subject: Router cutters From: bearhwk27- In retrospect the main difference between routing with an end mill or a laminate router may be the actual router itself. Differences in spindle speed ( cutter velocity ) and torque are probably a large part of the equation. So if one is not working...... try the other. +++ #1430 Subject: Re: Form Blocks by the pound From: Alan Nauman I followed the Router Workshop for a long time and that is the method I used to build my router table also. I looked for the mounting plates but they were like $30 for a little peice of plastic so I made my own out of a piece of plexiglass. I set the plate into a sheet of laminated particle board that is about 2'x4'. I usually just clamp the table down to a couple of saw horses for a stand. That way I can set the router on a shelf and put the table against the wall when not in use and it takes up very little space. I was going to use a similar method for the form block but I was not going to use aluminum for the pattern. I have not decided what to use of the patern but some cheaper wood. I bumped into a sheet of stuff at Home Depot that I will probably use for the form block. It is 3/4 or 1" masonite. It has all sides finished and it weights a ton. It didn't have a price so I don't know the cost but ut had a label and it was called SUR something. I have never seen or hears of this size and finish of compressed wood product but it looks like it is just what the Dr. ordered. Looking forward to receiving my plans. +++ #1435 Subject: routers From: Ernie Romito I have used a router for building many pieces of furniture. I would feel more comefortable using a router following a pattern rather than using a fly cuter. There is a catalog that has hundreds of router bits. They are usually carbide tipped. It is Eagle America. There bits that have bearings either on the top or the bottom. Just be careful to keep the aluminum chips away from your eyes. A router can be capable of making precise cuts but be really careful. My machines turn more than 24,000RPM. +++ #1532 Subject: Re: Ceremonial Removal of the Tags From: Russ Erb > Russ, what did you use to stamp the dog tags with the numbers? I bought a stamping set from Harbor Freight (Item 00800). These are little pieces of steel with the letter or number on one end, just like moveable type. Whack it on the end with a hammer to stamp the character. $8.99 on the Harbor Freight web site. +++#1533 Subject: Re: Ceremonial Removal of the Tags From: Alan Nauman I just picked up the adds at the locak store and the same stamp set is on sale for 4.49. +++ #1741 From: Schutt, Barry C Subject: [Bearhawk] Re: Scotchbrite > For all you folks who have completed your wings... > > What are your recommendations for purchasing Scotchbrite pads > and wheels? In other words, what worked best for you? In Mike's > rib book you can see a photo of Bob with a wheel in his drill > press. I'm wondering what colors and sizes worked best. I'm > leaning toward 2" purple, and maybe rose pads. Any thoughts? > There's a lot of 100 tan pads on eBay, but I think tan would be > WAY to coarse. I've found that I use some fine, some medium(rose) and some coarse(tan), but mostly fine(blue)---get some of each and try them out. +++ #1742 From: Russ Erb Subject: [Bearhawk] Scotchbrite > For all you folks who have completed your wings... I haven't "completed" my wings but feel qualified to answer. I use the Maroon pads. Works good, and the aluminum oxide grit is corrosion friendly to aluminum. Buy 'em by the box from Avery (20 pads/box). Get the 7A medium grade wheel from Avery for your grinder (6"). Not cheap ($43), but given proper care, it should last the project. Buy several of the smaller wheels--they don't last as long. +++ #1744 From: Tim Anderson Subject: [Bearhawk] Re: Scotchbrite Maybe it's just me (or my poor handling/stacking skills) but I have a lot of scrach marks on my rib blanks, during cutting, drilling, forming. I have been using both maroon pads and/or 400 grit wet/dry sandpaper (with water). The pads seem to work good on the edges and the wet paper does a nice job on the scraches. I should probably get some fine scotch pads. The wet paper does make things a bit messy. I wish there was a way of appling a thin protective peel off coating to the alum, to prevent handly scratches. Oh well. maybe wrapping the darn thing in plastic suran wrap would work. Or maybe there is a spray-on coating. +++ #1754 From: Bearhawk390 Subject: [Bearhawk] Re: Scotchbrite i took a sheet metal coarse from Sportair last year and the instructor recommended coating your aluminum with ZinkCromate before you start to work it. i tried it and it works great, only takes a VERY light coating you can brush or spray on. Available at wicks, if you don't want to use it as your permanent corrosion protection it will wipe right off with lacquer thinner when your finished good luck. +++ #1756 From: Donald Schindler Subject: [Bearhawk] Re: Scotchbrite Another thing the old pro's used to do was to dip their rivets in Zinc Chromate before they bucked them. It gave real good corrosion proofing and after it dried, if you had to drill the rivet out, the chromate would hold it and keep it from spinning. Im not an old pro Im just old. +++ #1771 From: Donald Schindler Subject: [Bearhawk] Re: Tack welding Kelvin, I think that you might just need to do more jigging before you pick up your torch. If you've never tried Mig welding you may have a tougher time with a tack than with gas, particularly on vertical tacks and nearly impossible overhead. To help your jigging get a set of Lowbuck adjustable tubing clamps(www.lowbucktools.com) they help alot. I prefer TIG myself but it is a fact that Mig is employed by numerous aircraft manufacturers(Kitfox, Mooney, Bellanca) for it's speed. +++ #1785 From: Tony Dean Subject: [Bearhawk] Re: Tack welding The snippet below raised a question about preparation and setup. I plan to seal my tubes with line oil and that means that I have to drill holes for the oil to enter the uprights and diagonals. If you tack weld, do you drill all the holes for uprights and diagonal tubes before tacking (I presume you do)? Or, would you simply not oil treat the uprights and diagonals? The examples I have seen are ones where the oil holes are drilled and after the fuselage is completed you turn it up on end and pour hot oil in one end and let it flow throughout the tubes. Any ideas? +++ #1786 From: Russ Erb Subject: [Bearhawk] Re: Tack welding > If you tack weld, do you drill all the holes for uprights and diagonal > tubes before tacking (I presume you do)? Or, would you simply not oil > treat the uprights and diagonals? I plan to oil the tubes (another controversial topic if you talk to Richard Finch). The trick is remembering to drill the little hole before tacking the tubes in place. Poly-Fiber sells a good line oil for anyone looking for a source. +++ #1788 From: Bruce A. Frank Subject: [Bearhawk] Re: Tack welding I would drill holes allowing communication between all the tubes. I started with a salvaged fuselage which did not have holes between any of the existing tubes. For all of the new structure I added I first drilled an eighth inch hole to allow this free communication between longerons, diagonals and vertical tubes. For the tubes already in place I drilled through from the outside of the longerons, up through the clusters, into each of the tubes. I then welded up the remaining hole in the outside of the longeron. +++ #1797 From: Zippydogg Subject: [Bearhawk] Re: Tack welding I was thinking of interconnecting all the major tubes in the fuselage, and plug the ends. I would then install a shrader valve (tire stem) and pressure gage. After welding is complete, but before the first flight, the time required to "leak down" from some particular pressure would be measured. Then periodically, I could accomplish the same test. A shorter time to "lead down" may indicate a crack. This would also be a good way to get the tubes completely sealed. IMHO this would be the best rust prevention measure. This method was used on the Porsche race car frames in the distance past. +++ #1798 From: Russ Erb Subject: [Bearhawk] Re: Tack welding > I was thinking of interconnecting all the major tubes in the fuselage, > and plug the ends. I would then install a shrader valve (tire stem) > and pressure gage. After welding is complete, but before the first > flight, the time required to "leak down" from some particular pressure > would be measured. Then periodically, I could accomplish the same > test. A shorter time to "lead down" may indicate a crack. This would > also be a good way to get the tubes completely sealed. IMHO this would > be the best rust prevention measure. This method was used on the > Porsche race car frames in the distance past. I've heard of this method. In fact, it is mentioned on page 112 of the EAA "Aircraft Welding" book. What you didn't mention is that it involves filling the tubes with nitrogen--you have to get the oxygen out for it to work. Have fun finding those pin-hole leaks that always seem to exist. If you use line oil, the stuff has such incredible capillary action that it will work it's way out of pinhole leaks. Leaving the pin hole leaks in probably wouldn't be a problem from a corrosion standpoint, but it would be so ugly to have it come out on your fabric. Either way, you still have to remember to drill those holes! +++ #1800 From: Bruce A. Frank Subject: [Bearhawk] Re: Tack welding After the fabric is on what do you plan to do if the pressure gauge shows you have a leak? Cut off the fabric? How are you going to find that leak? Just put connecting holes in all the tubes and install line or linseed oil. The oil will clot and seal any pin holes. You may be loosing sight of what you're trying to accomplish. Oxygen inside the tube in a fully sealed system presents no rust problem. A little light haze rust forms on the inner surface of the tube and that is it. Once the small amount of oxygen has reacted with the surface of the steel no further rusting can take place. The object is to prevent "breathing" of the tube during barometric pressure and temperature changes. Such breathing carries in fresh oxygen (necessary for rusting) and moisture. With the system oiled, besides sealing any pin holes, the oil eats up any free oxygen. With no free oxygen, even with water present, no rusting takes place. If a small crack eventually forms (no single crack is going to cause catastrophic failure in these truss style tube frames) it is likely the internal coating of oil will continue to protect the tube. It is also likely that remaining liquid will seal that new crack to continue to protect the tubes. I have welded tube frames that showed absolutely no leak down over 4 weeks. But once the frame was put in service the pressure leaked out. No crack, just a pinhole unclogging from the bumps and flexing. Linseed oil prevents such a problem. I once cut apart a gear leg from a TriPacer that had been rebuilt 30 years in the past. It had been oiled when rebuild (though the original Piper leg was not). When I opened up the rear tube of the leg it contained about 8 oz of water and 4 to 5 oz of still liquid linseed oil. There was not one speck of rust in that tube(the plane had been in dry storage for 15 years). I actually sawed it full length to be sure that there was no rust present. Don't know how the water got there, but the oil still did its job. Use the oil and don't worry about all those "what ifs". +++ #1802 From: Tim Anderson Subject: [Bearhawk] Re: Tack welding General questions on the oiling process. Correct me if I'm wrong. 1. Drill all interconnecting holes at tube joint locations (prior to welding) Bruce your drawing is great. 2. weld the frame completely 3. poor in hot linseed oil to several locations? How much? 4. seal up the tubes 5. rotate the frame to prevent pooling? But how does one prevent oil pooling at the low spot in the frame when all the tubes have interconnected drain holes. On the taildrager, all the oil will end up in the lower tail (which is probably where any water or condensation will also pool). The top of the fuselage will never see oil after the initial application. +++ #1804 From: Russ Erb Subject: [Bearhawk] Re: Tack welding > But how does one prevent oil pooling at the low spot in the frame when > all the tubes have interconnected drain holes. On the taildrager, all > the oil will end up in the lower tail (which is probably where any > water or condensation will also pool). The top of the fuselage will > never see oil after the initial application. Line oil (Poly Fiber Tube Seal) has incredible capillary action such that it will climb up the inside of the tubes against gravity. I can't tell you why it does that but I've seen it happen. Thus the oil will stay in the top tubes. Oil pooling at the tail is not a problem (only a few ounces of weight), and a good place to have it if that's where the water collects. +++ #1806 From: budd davisson Subject: [Bearhawk] tube oiling Bruce brought up an important point about internal corrosion: it needs oxygen to happen. I don't know the percentage, but a major percentage of the old fuselages weren't oiled on the inside and many just oiled the longerons. Drilling and oiling all the diagonals is a great preventative measure but in cutting up and repairing dozens and dozens of old fuselages, I don't think I've run into internal corosion more than a couple of times and then it was the result of exterior rust pinholing the tube and letting air/moisture in. Sloshing line oil in there and making sure every tube is sealed will make it last into the next century. Sloshing the oil in and not welding everything as tightly closed as possible, may let oxygen do it's thing, dispite the oil. Another thing, is making certain the exterior of every cluster joint is completely clean before painting it. If a piece of scale flakes off after painting it, all the line oil in the world won't help, as it'll start rusting from the outside. We have a local powder coating outfit that does a terrific job of gently (repeat, gently) blasting a fuselage and then powder coats it any color you want for $300. I think it's worth the investment. Incidentally, safely sand blasting fuselages is an art: don't turn it loose with your local pool contractor. +++ #1815 From: budd davisson Subject: [Bearhawk] Re: ADEL clamps How about bandsawing a wide notch, the width of the bolt, in the nose of a cheap pair of vice grips and maybe grind the nose down so they are pretty thin. Clamp over the adel and slip the bolt through the notch. just thinking. +++ #1816 From: Derrick Howard Subject: [Bearhawk] Re: ADEL clamps You can use waxed tie string(used to tie up wire bundles)looped & tied through the bolt hole. The wax will keep the clamp closed, still able to get the bolt in(barely), & you can either leave the string tied, or cut it away. +++ #1817 From: Tim Anderson Subject: [Bearhawk] Re: ADEL clamps My thoughts exactly. Maybe two flat plates welded or BRAZED on the jaws with a slot for the bolt/nut. +++ #1822 From: Russ Erb Subject: [Bearhawk] ADEL clamps One answer to ADEL clamps is just plan to be frustrated. Vise-grips are a definite plus. I like the safety wire idea--that never occurred to me. Here one I developed for a specific condition. My main wiring conduit is held in with ADEL clamps, and I realized that I had cleverly placed it through the lightening holes in the nose ribs in such a way that I couldn't get my arm through the lightening holes in the main spar to buck the rivets on the nose skins. The conduit was just in the way. I had already installed all of the brackets to hold the conduit and liked the way they turned out. There were several options: 1. Leave the conduit in place and use blind rivets to attach the nose skins (No good--lose most of the cool points gained from flying a Bearhawk, especially around other Bearhawk builders. Not to mention the question of 1) rivet strength, or 2) cost of that many cherry max structural rivets). 2. Cut seven more access panels in the bottom of the wing (Too much work, also ugly) 3. The answer: Pre-attach the clamps to the conduit using machine screws and thin jam nuts. This holds the clamps in place. After riveting the nose skin on, slide the conduit in place, insert remaining end of machine screw through bracket, and install nylon stop nut. I have checked and there is sufficient room to do this at each location either through the lightening holes in the spar or access panels installed for other purposes. The intent is that the conduit would never have to be removed. For the very small probability that it did, a few new access panels would have to be installed. +++ #2112 From: bearhwk272 Subject: Fire in the workshop ! Just a friendly safety reminder. If you happen to own and use a belt sander, with or without a dust collection system be cautious of the following. Sand a bunch of wood for tooling and household projects, sand a bit of aluminum for the Bearhawk, sand 4130 for flap and aileron hardware.... AND POOF FIRE in the belt sander guard. Various material buildups had occurred in the pulley hubs and "dead" areas that just managed to ignite from the steel sanding sparks. No harm done this time. Hate to think what might have happened if it had migrated into the dust collector / Shop Vac. Back to sanding. +++ #2116 From: Russ Erb Subject: [Bearhawk] Fire in the workshop ! FIRE IN THE HOLE!!! Excellent point, Kevin, and one I had not thought about. I keep a fire extinguisher handy in the workshop. Its expected use was primarily during welding, but would be good for this case too. While welding I also have another system available--the faucet on the sink in the shop has a hose thread on the end. I attach a garden hose to the faucet, and a spray nozzle to the other end. Water on full pressure, with the nozzle in a bucket in case it leaks. If fire breaks out (beyond minor scorching of plywood that can be blown out), grab the nozzle, squeeze, and its gone. Won't do wonders for the temper of your weld joint, but at that point the weld is way down the priority scale. Haven't had to use it yet, but I'd much rather have it there and not need it than the other way around. If you don't have a sink available, you can run a hose in from the back yard. +++ #2158 From: Bill Cox Subject: Re: [Bearhawk] Other - New Airstrip I have a tube notcher (ol Joint Jigger), but usually use a pair of compound snips and finish with a file. My neighbor uses his quite a bit, so I guess its what you get use to. His is from Harbor Freight and it's an exact knockoff at less than half the price. The welding gets easier with practice. It sounds like you got the fundamentals. Same with the riveting, you'll probalbly buck most of your own rivets. I spent a bit of time with the Lincoln folks learning to weld Al with the Lincoln 175. I did alright with him looking over my shoulder coaching, will I do OK on my own? We'll see next week. Sounds like you made a good haul. I believe I have every thing for the wings. The skins are on the way from Airparts. +++ #2175 From: Mike Eldredge Subject: Re: [Bearhawk] Welding fuse clusters What kind of tubing cutter did you buy that you don't think you will use much? I ask because I'm considering buying the tubing notcher from Harbor Freight. What do they recommend for cutting? +++#2178 From: Kelvin Gurney Subject: Re: [Bearhawk] Welding fuse clusters I bought the expensive one listed in most aviation magazines. I have heard the Harbor Freight notcher is an acceptable copy. I made that comment because they show a technique using tin snips and a bench top grinder that combines the measuring, cutting, and fitting into one fluid operation. I have played around with my notcher to get a feel for it. I think there are two disadvantages to the notcher: a) Clamping and unclamping the tube every time you want to make a cut takes time. b) Measuring the angle and transferring that angle to the notcher takes time and is prone to error. The advantage to their technique is: a) It's quicker. You are making the cuts standing at the fuselage jig. No clamping and unclamping of tubes. b) It's intuitive. You mark the angle with your thumb and make small cuts. Less chance of error. I think the notcher is useful. I would guess where you have complicated clusters the time spent setting it up and running test cuts would pay off. It just after seeing the video I realized there was a quicker, simpler way. Keep in mind, this is the opinion of someone who has yet to build his first fuselage. +++ #2179 From: Bill Cox Subject: Re: [Bearhawk] Welding fuse clusters I have the high dollar notcher, my neighbor has the Harbor Freight model. They appear to be nearly identical. He builds fuselages for an ultralight kit and uses his to some extent. He also cuts a lot of tubes useing a reamer in his lathe. I mostly use the snip, file, grind method. It seems to go the quickest. +++ #2180 From: Bob Romanko Subject: RE: [Bearhawk] Welding fuse clusters For what it's worth..... In 1981 I went 21 months through my A&P school, and there wasn't a tubing notcher in site. I passed my FAA Airframe practical exam with a cluster weld done entirely with snips and a rounded wheel on a grinder. Once I got the hang of the technique I can't imagine how I could make a joint any faster with a notcher. +++ #2184 From: budd davisson Subject: Re: fitting tubing Yet another opinion, Don't complicate your life by a) trying to get absolutely perfectly symetrical fits and b) by using something that adds time to notching the tubing. IN the first place the fits don't have to be perfect. Remember you're going to melt most of the edge so if it is a little rough, it doesn't make any difference. The tiny sharp corners caused by the edge of a griding wheel melt first and smooth out with the rest of the puddle. What you don't want is tubing touching tubing,because it needs a little space to expand. A .030-.040 gap, or the thickness of a handsaw blade, is okay, but it doesn't have to be perfectly even and tight unless you're tigging, which works better withtight fits. Setting up the tubing notvcher and all that takes unnecessary time. Every single person reading this has their own method and Iv'e used most of them. I finally settled on dressing my grinder wheels to a point, not a radius. I lay the tubing in place and make a mark that runs across the diagonal and overlays the cenerline of the longeron or cluster centers. That gives me the angle to cut it, which I do on a cheap metal cutting band saw. Before I cut it, however, I mark the end of the diagonal front and back (fore and aft on the airframe), paralleling the longerons. This helps me keep the radii at each end lined up. I then grind a deep notch on each side of the diagonal where the centerline marks were with the pointed wheel. I take a short piece of scrap tubing of the size the diagonal is going to meet and use it to draw a rough radius around those notches. Then I grind to that mark using the sharp edge of the wheel to "wipe" the metal away. If it takes 5-8 minutes an end to do all of this, it is a lot. For those of you have haven't put a piece of .035/49 to a bench grinder: it disappears in a hurry. I fit one end before I notch the other end, that way I can make sure the notches parallel and the length is right. In my mind, it's better to do it fast, rather than perfect, because then you don't have much time invested in it and you are perfectly willing to scrap the piece and do it again. If it has taken you 15 or 20 minutes, between measuring, setting up the tubing notcher (it's easy to get the centerlines wrong and cut a piece "just a little" too short and be tempted to use it) per end, you're going to be less willing to start over. And don't worry about wasting the piece of tubing. If there is one truth in scratch building, it is that there ain't no such thing as too much scrap tubing. You'll use it up for something. Like I said, yet another opinion. Take it for what it's worth. +++ #2189 From: Bruce A. Frank Subject: Re: [Bearhawk] Welding fuse clusters I have always found the tin-snip method hard on my hands. I have a Joint Jigger(a poor quality tool when more than a couple of hundred joints need to be fish-mouthed) that I use extensively to build engine mounts and landing gear for the V-6 STOL, but I know all the angles and lengths so it's a fast process for me.(Actually, I now use a similar tool built by Elwyn Johnson, when he owned Northwest Aero, that uses hardened parts and roller bearings. It has produced several thousand notches without a problem) If you are building a one off fuselage there is nothing faster than a bench top grinder with wheel dressed to a radius, rather than flat. An end of 1/2" or 5/8" diameter .035" or .049" wall tube can be ground to shape in 30 seconds. It is a fast process. Fit up does not have to be perfect. Even occasional gaps of 1/8" really present no problem either with welding procedure or ultimate strength. I also have found one of those 4.5" right angle grinders, with a hard wheel that has its edge somewhat rounded from use, to be very handy for notching tubes while standing right at the fuselage. I consider a file a tool for fine, rather close tolerance work. Fuselage fit-up does not require that precise a fit. Once in a while I'll grab a rat-tail file to remove burrs from the inside of a tube that will sleeve another, but for the most part files are tedious when there are 300 joints to be made. Diagonal tubes can be a problem if the verticals and horizontals are hard in place. An easy method I use when faced with a forgotten diagonal, or a need to add one when making a change, is to cut a length of tube about 2" shorter than the needed piece. Cope both ends to fit the cluster into which each will fit. Then cut another 6" long piece of the next diameter that will snuggly slip over the first tube. Both ends of the 6" tube should be cut at a 30 to 45 degree angle and drill several holes suitable for rosette welding. Cut the first tube in the middle and insert the pieces, center cut end first, into the 6" sleeve. Slide the inner tubes out to fit into each position in their clusters, center the sleeve, tack all contact points, then weld the clusters, rosettes, and the angle cut ends of the sleeve. You then have an easily fit solid diagonal with little extra weight and no gob-on welds needed to fill the gaps needed to insert a full length diagonal. +++ #2491 From: Russ Erb Subject: Re: [Bearhawk] Short-Winged bearhawk Club I agree that the fan rivet spacer is well worth the money. I use mine frequently. However, I must differ with Forrest on one point. The instructions that came with it said do NOT use it as a drill guide. Besides the inevitable enlarging of the holes, you'll end up with a non-straight line of rivets. The technique is to draw a line, mark the locations with the tool, then drill on the line where the marks are. If you do this you will see that the holes in the spacer don't stay perfectly lined up but form a slight arc when the tool is expanded. I haven't worked out the geometry as to why yet. Clecoing the end points in does work very nicely if you can do it. +++ # 2499 From: mailstuff Subject: Re: [Bearhawk] Short-Winged bearhawk Club You have to be careful when you drill through the rivit spacer, but it can be done. I have one that is five years old and it still holds a #3 cleco just fine. Another thing you can do is use a spring loaded punch to mark the locations and then remove it and drill at the pricks. +++ #2580 From: Bob Romanko Subject: Leather Mallet/Hammer Source? I'm looking for an old ratty leather-faced hammer like we used at PIA back in 1979. No luck. Who the heck sells these things? I'm bangin' ribs with plastic, but much of the nostalgia is lost. It's just not the same. Call me a traditionalist. I'm tempted to get some 2" hickory, cut up one of my wife's (many) handbags, and just build my own. That WOULD be in keeping with the Bearhawk tradition. I've searched all over the web, and can't find a source anywhere. Howsaboutalittlehelp? Thanks, folks. And WATCH that rivet spacing out there! +++ #2581 From: budd davisson Subject: Re: [Bearhawk] Leather Mallet/Hammer Source? I am now officially let down in Bob "don't use anything that's already made" Romanko. Cutting up purses when you could be out there growing the cows, preferrably thick skinned ones? Try the "tin man's" website. I don't have the URL but someone will. And don't cut up the purses, go buy a couple of sole blanks from your local shoe guy. It's nice thick stuff. +++ #2583 From: Bruce A. Frank Subject: Re: [Bearhawk] Leather Mallet/Hammer Source? > I'm looking for an old ratty leather-faced hammer like we used at PIA > back in 1979. Have you tried Brookstone or McMaster-Carr? +++ #2584 Bion Rogers Subject: Re: Leather Mallet/Hammer Source? The following is available from Brownells, a gunsmithing tools supplier. They have a wonderful warranty ( If your not happy with it, send it back for refund or replacement)I use them in my gunshop all the time. These are the old style thick layer wrapped, boiled in wax, animal glued kind that everyone wants but always says they can't find them Made in the USA. Brownells has many hand tools that are impossible to procure anywhere else, and I'm not just talking about gun tools or parts. This is from their on-line catalog at brownells.com Perfect "Soft Touch" For Wood & Finished Metal Great for gently tapping on a barreled action during inletting or driving a 1911 slide back and forth when lapping it to the frame. Won't mar wood or metal. Head is made entirely of rolled rawhide. White hickory handle. SPECS: Rawhide Mallet No. 1, 4 oz. (113g) head, 11/4" (3.2cm) dia. x 31/8" (7.9cm). No. 3, 8 oz. (226g) head, 13/4" (4.4cm) dia. x 33/8" (8.6cm). Head lengths and dia. will vary with the density of the hide but will normally be within 1/2 oz. of specification. Stock No. Product Price Qty. 672-196-001 Rawhide Mallet No. 1 $17.10 672-196-003 Rawhide Mallet No. 3 $24.85 +++ #2634 Doug Knight Subject: Re: [Bearhawk] Seeds, Skinning Cats, and Brown Trucks Against my better judgment, "a cobbler's kid has no shoes." I'm right on the edge on making a commitment on building various tooling and jig fixtures for rent. What I need is a little feed back for planning and design engineering. My current thoughts are wood is fine for one off, where metal dies would last a little longer. Some how there would have to be set a standardized hole and finish process regime to allow the dies to have a long cycle life. If the field builder has improper holes sizes and poorly hole edge deburing and scotch brite finish. With that said I currently am thinking of 7075 dies and shoes. Singles for each hole sizes. These would work to with either all thread compression or in a press depending on what you have in your home shop. Now for what I do at my work, I am the lead fabricator/welder in a small fabrication company that builds theme park structures and theater set, and for rock and roll touring shows. There I build all the tooling and jig fixtures that produce either one or multi copies of parts. The inventive process is a daily thing for me. So what other tooling and fixtures you guys think might have a need for? And for those interest I haven't Gas welded in over 30 years and plan to do ALL my welding with Tig. I have several heat treaters here in town that could normalize my fuse when finished. Maybe I'll have it powder coated too, that guy lives 4 houses down the street from me. I think of a tube fuselage as just a micro truss. +++ #2902 From: Bob Romanko Subject: RE: [Bearhawk]brakes and stuff You have a good point about the space. That's why I designed my shop from the ground up. I used pole construction so I can knock out wall panels on opposite sides and hang the wings ala T-hangar. I also built a second floor to store parts and materials. It's pretty interesting when folks drop by to see the "Bearhawk" and don't see anything but the part I'm building at the time. When I finish with a set of ribs I store them upstairs, so I rarely have more than twenty or so blanks on my bench at any one time. If you look at my build log and then look at my shop, you'd be quick to call me a liar! I guess until I start pounding the spar together, the shop's going to be pretty bare. One thing I learned from visiting other builders is that most of their space is taken up by part storage and Christmas decorations, not necessarily with tools. Sure, not everyone has the luxury I was blessed with, to be able to build a shop for the purpose of Bearhawk construction. I do, however, think that for quite a few folks it would make sense to find someplace else to store the parts and household items that take up valuable shop space. Some of the U-Store-It places around here are dirt cheap, and in the total cost of construction it may make sense to take advantage of those places if it means making space for more tools (heehee). As an example, right now I have a tiller, lawn tractor, 55 gallon oil drum, Shopsmith, 2-ton hoist and a push mower stored in my shop. This is driving me bonkers. I'm building another building, a shed, that will be 12'x16' with ten foot ceilings and a 12/12 pitch roof for rafter storage. I thought that having those things in my shop wouldn't be a big deal, but every morning when I'm pounding/cutting/polishing aluminum I'm looking at them "invading my Bearhawk Sanctuary". Not good. Justifying to my wife that I need another 192 square feet after just building a shop that's 1,152 square feet hasn't been easy, but I think I'm wearing her down. Time will tell... +++ #2953 From: Hedges, Bill Subject: RE: [Bearhawk] back to work What's the name of the book on fabricating tools? I'd be interested in making tools over buying them new. Haven't looked too hard for used ones yet, we have a 10 ft brake at work, all I would like is a 48 " shear, a 48" brake, a drill press, tools like that. +++ #2959 From: Michael Geurink Subject: Re: [Bearhawk] back to work I was just reading about this book on the packrat faq. It's Racer's Guide to Fabricating Shop Tools. Plug that into the title box on an Amazon.com book search & it will come up with the book. Only problem is it's out of print or they have to search around to find it or something. Since I'm in Brazil I rely on people coming down here to transport books & parts & things I order. Since they had no guarantee of getting it by a certain time I couldn't get it or I'd be happy to give you a review. +++ #2967 From: Subject: Re: [Bearhawk] back to work The tool fabricationbook is "The Racers Guide To Fabricating Shop Equipment", by John Block. There are 6 well documented plans in it, though most of the tools are more useful to an auto builder. There is a plan for a nice hydraulic press. The main reason I haven't yet put together the parts for the brake is because it isn't a true center pivot brake. I don't know whether the small offset of the blade will make a difference when bending, but I hate to build it and find I ended up with a 40 pound boat anchor. I will put it together some day. +++ #2971 From: Daniel Fox Subject: Re: Fabricating Shop Tools book I just tried to order this book from Amazon a few weeks ago. They said "special order wait 6 weeks." 3 weeks later they said "Sorry no can do. We credit your account." Incidentally, I got the same thing when I tried to order Richard Finch's guide to automotive engine conversions for homebuilts. Any ideas on where to source that? I'm having a hell of a time trying to burn through this gift certificate. :-) Any suggestions for books for a wannabe homebuilder? +++ #3022 Subject: Re: [Bearhawk] Other: Oil Free Air Compressor? From: mailstuff > I happened across a two year old air compressor for $200. > It's oil free, but the specs look pretty impressive. This > one may be tough to pass up. A friend is selling it: > > Craftsman Model # 919.152930 > H.P. 6, Direct Drive > CFM 21.2 > Volts 240 Single Phase > SCFM @40psi - 15.0 > SCFM @90psi - 11.5 > > It has a 33 gallon tank, and it's on wheels. If it has greater than 10 scfm at 90 psi it will run any air tool continuously. I have a few that are air hogs and they won't run down a compressor of that size. Go for it! (mine new was $400 from harbor freight with a 60 gallon tank - as a reference for price) +++ #3023 Subject: [Bearhawk] Other: Oil Free Air Compressor? From: Russ Erb > I happened across a two year old air compressor for $200. It's > oil free, but the specs look pretty impressive. This one may be > tough to pass up. A friend is selling it: Listen to it run first. Oil free compressors tend to be LOUD! Oiled compressors are much quieter. I have an oil free compressor and it is located outside the shop and plumbed in because of the noise. +++ #3024 Subject: RE: [Bearhawk] Other: Oil Free Air Compressor? From: Bob Romanko This is the $399 one from Harbor Frieght/Northern Tool I was planning on buying before I found the used Craftsman: Model VT 6275 6.5 HP Vertical 60-Gallon Tank 11.5 CFM at 40 PSI 9.1 CFM at 90 PS 125 PSI maximum 230 Volts Oil-lubricated Twin cylinder Belt-driven pump If I just compare the ratings, other than the size of the tank and the fact that the Craftsman is oil free and direct drive, (oh...and it's $200 less). I'd have to say the used Craftsman seems to be the deal. My concern is I'm not real familiar with direct drive/oil free compressors. I figure if it makes it through the Bearhawk I'll be doing fine. Shoot, I'll probably spend more money on clecos... +++ #3040 Subject: [Bearhawk] back to work From: Russ Erb > What's the consensus on buying a shear/roller/brake? What size? > Any other major tool suggestions for reducing the time and > frustration without breaking the bank? My recommendation is to first join an EAA chapter if you haven't already. Then find out what members have such tools that will let you use them. I've gotten a lot of work out of an 8' brake, 4' shear, and bead roller that a friend has. Good thing, too, since I wouldn't have room for them anyway. Of course, you'll have to decide when the convenience of having your own outweighs the cost of purchase and the space requirements. +++ #3047 Subject: Re: [Bearhawk] back to work From: Donald Schindler There are alot of opinions on this but a real useful tool is the 3 in 1 brake, shear and roll like you can buy at harbor freight. It will do alot for the money. They sell them in 30 inch and 40 inch models. Try and hold out for the 40 inch if possible but I know alot of guys who do fine with the 30. If you have the time to wait they do put them on sale regularly. I have plans that I bought for a 8 foot tongue brake that if anyone is interested in I will supply info on. It uses 4 hydraulic jacks and is not to complex as far as brakes go. This is the type of brake they use at Boeing. It does require some good welding though. +++ #3049 Subject: Re: [Bearhawk] back to work From: mailstuff My dad bought a shear, press, and brake combination from Harbor Freight and he hates it. He has been an A&P for over 40 years and thought this would be a nice thing for working on homebuilts. He stated that it takes too long to switch between the operations, it does nothing really well, and you always have it set up for what you don't need to do ( and after you switch it, you realize you forgot to do something that had to be done with the previous setting) If you are really a patient person, it will probably work fine. My dad hates to spend a lot of time setting up a tool. You better have a good bench, because these things are really heavy! +++ #3117 Subject: RE: [Bearhawk] Tool sources From: Bob Romanko Good advice. If you go to an auction, even if something doesn't work, you can collect enough junk to make one good compressor if you're patient. I picked up a VERY nice 30 gallon tank and pump with no motor for $10 at the University of Virginia auction. It's still not what I'm looking for, but better than what I had. Don't worry TOO much about the three phase motors. It's not a big deal to hook up a three phase motor to a single phase circuit. You can build the converter yourself, or keep your eyes out on eBay for one. The max HP motor one should consider for this is about 7.5HP, which is MUCH more than the typical (but then again, few of us are "typical") Bearhawk'er should need. For you folks out there who want to understand 'lectricity real good, check out this URL: http://theoak.com/rick/Electricity_in_the_Shop.html Good stuff there that takes you from neophyte to sparky in no time flat. ...and yes Mr. Budd "Big Fancy Pilot/Author/Etc." Davisson, I DO have 'lectricity on my side of the mountain! +++ #4071 From: "Kent White" Subject: Re: [Bearhawk] Digest Number 232 >> Even slower yet are videos ordered from Tinman I had hand >> carried into the country. Here I was in the Amazon for a >> month & a half knowing that my 4130 videos were in S o Paulo. >> They finally arrived, and I've re-upped the itch to get >> started again. Just the old time/money thing in the way yet. Just finished a 4day training here at Homebase, and had one IA from Chugiak, AK. BTW, the recent series of aerometal articles in Sp. Av. are segments for the new video on Fairing construction, and this recent Training also allowed students to both watch and use the new Airhammer prototype dies for fairing construction. Judging from the extruded eyeballs, this new tooling moves the metal along quite acceptably. (The acid test will be the polished fairings for the H1 later this spring.) Happy students all around. +++ #4123 From: Russ Erb Subject: Safety with fiberglass cutting discs I had a friend weld up my fuel tanks recently, and was generally pleased with the results (read: he did a much better job than I would have). Of course, there were the pin-hole leaks that always occur, but I intend to take care of those with exterior application of some Pro-Seal. Possible more on that later. However, neither one of us were happy with the way one of the filler cap flanges turned out. Because of distortion from welding, it was out of round and had no hope of getting the O-ring to seal. (Odd, considering this was the second one that he did, and the first came out fine.) I finally decided it had to come off and be replaced. The only effective method I could find to cut it off was to use a 3" fiberglass cutoff disc in a drill motor. I was rather surprised at how fast the disc wore away while cutting through the thick aluminum welding bead. Seemed like I was removing 2 parts disc for each 1 part aluminum removed. Even so, it was working better than anything else. I didn't bother wondering where all of that fiberglass was going. Instead, I was trying to figure out when and where to get more to finish the job. About the time I quit, I started to realize where some of that fiberglass had gone. I finally recognized a familiar, though unwelcome, feeling. As is my custom, I was wearing a short-sleeve T-shirt in my heated workshop (one space heater and a bunch of insulation does wonders). My arms were itching, primarily on the inside (the part with no hair that never tans). It was an itch that I would get from working unprotected installing fiberglass insulation. Hmmm, think some of those fiberglass fragments had embedded in my arms? That's my theory. I put up with the itching for a while, thinking it would eventually go away. I woke up about 2300 still itching. For some reason, I suddenly remembered the treatment, which I immediately applied. It's sort of like lint removal--Get some sticky tape (I use plastic packing tape), apply it to the effected area, press down, then pull it off. RIP! Repeat several times. Believe me, the itch is so annoying the pain of hairs pulling out is actually a relief! The idea is that the tape is pulling out the fiberglass fragments. This was told to me by a composites builder. The same problem can occur when sanding fiberglass. But that wasn't all. I woke up this morning with a sore throat. I've had lots of sore throats, but this one felt different. I think I inhaled some fiberglass dust and it is irritating my throat. Tape won't help with this one--only time. Now, none of this is incapacitating, but why put up with the pain/annoyance if it can be prevented. When I finished up the job today, I wore a long sleeve shirt. No itchies so far. I also used a respirator to protect my throat. I also used some goggles figuring my eyes could use the same protection. I have typically avoided using goggles (not a good practice) because the pair I had were hard to see through and I already wear glasses. Those reasons seemed pretty silly when I noticed that I could get a new pair for under $3. While I'm at it, I'll also say that I frequently wear hearing protection, because loud noises hurt, or are at least uncomfortable, and I don't want to lose irreplaceable hearing when it's easy to prevent. Thus endeth our safety sermon for today. Remember, practice safety in the workshop so that when you finish your Bearhawk you'll be able to enjoy it! +++ #4124 From: Benton Holzwarth Subject: Safety with fiberglass cutting discs > I have typically avoided using goggles (not a good practice) > because the pair I had were hard to see through and I already > wear glasses. Those reasons seemed pretty silly when I noticed > that I could get a new pair for under $3. Brings to mind the story someone posted sometime back of having been checking the action on punch and having a shard come out, miss the goggles but embed itself in the lip. I took that story to heart, and bought myself a full-face shield. Fits over the glasses just fine, tho' does tend to fog up bit when it's cold. +++ #4125 From: Jim Ash Subject: Re: [Bearhawk] Safety with fiberglass cutting discs One of the tricks a local builder taught me was to take a cold shower as soon as you get done handling fiberglass. As cold as you can possibly stand it. If you take a hot one, your pores open up and the fibers can get inside them, then you itch for a week. I haven't had the fiberglass itchies since learning that trick years ago. +++ #4129 From: Tim Subject: Re: [Bearhawk] Safety with fiberglass cutting discs I second that Jim, when building Hinckley fiberglass boats in Maine, those words on the cold shower 'first' were instructions from the shop foreman...Of course being 18 yrs old I just had to find out for myself. One day after grinding decks, I reversed the shower order.....That was 28yrs ago and I vividly remember that night still, Mr Lobsterman, wicked/brutal..... +++ #4131 From: Tim Subject: Safety with cutting discs Serious business...; Lose an eye, your depth perception and your flare....I think about the loss of aviation when I tell myself, I don't need my safety glass for this quick 2-second job.....My wife's uncle lost an eye to a welding spatter, I saw it while it was going bad about a week after medical treatment, when he lifted the patch... When I was in the Hospital with my Military 3degree AC joint separation operation, a 23yr old mechanic was in the bed next to me with a splinter in his eye, that after 2 failed attempts still wasn't removed....He was in a lot of pain and on 100% drugs....I was talking with his Dad, who the doctor gave the task, to tell his boy it had to come out and I don't mean the splinter.......I also think about that when I'm not motivated to find that 'last resting place' of my safety glasses.... +++ #4132 From: Bob Romanko Subject: RE: [Bearhawk] Safety with fiberglass cutting discs I think most folks are missing the boat that you impaled yourself with fiberglass! The velocity of the glass strands were like thousands of little darts, blasting away at your hairless inner arm. AAGGHH!!! Yup...the tape trick's the way to go. This is NOT the time of year for a cold shower, even here in Virginia. Fiberglass is NASTY, and I don't care what them weenie canard builders say. If God had meant for planes to be made of glass he wouldn't have given us 2024 and 4130 trees. Speaking of losing an eye, a good friend of mine had PERFECT vision and a not-so-perfect pair of safety glasses on. While operating a precision grinder, a piece of metal flew BEHIND his glasses and struck him square in the eyeball. After the operation he's now tied to glasses for the rest of his life. His good eye is still perfect. I tried on his glasses once and it was wild. One lens has gobs of correction, the other is just clear. Totally whacked. The irony of it all is he was using the grinder to form a piece to go into a machine to cut eyeglass lenses. Life's like that. +++ #4136 From: Warren "W. Shalm" Subject: Re: [Bearhawk] Safety with fiberglass cutting discs That's a good tip on the fiberglass removal. I've used it quite a bit on home projects but always just covered up which is miserable in the summer. If you're not working with fiberglass however here's a tip to help make you more comfortable in hot climates. I spent 15 years in India and they told us the way to avoid heat rash and skin problems from perspiration and body salts etc. was to first take a hot shower to open the pores and flush them out, then cool off with cold if you need to. It really works even though most of my Canadian friends think I'm nuts. Oh well, let 'em scratch. +++ #4148 From: Shelly Subject: Re: [Bearhawk] Safety with fiberglass cutting discs > The only effective method I could find to cut it off was to > use a 3" fiberglass cutoff disc in a drill motor. I wonder if part of your problem is the type of cut-off wheel you are using. I have been using a 1.5" "fibre-cut" (aluminum oxide) discs for general cut-off jubs on just about every kind of material for about 30 years with never a problem. They are made by Dedeco Co. If you think you would like to try one, I'd be glad to send you one - or I can tell you where to order. I use it in a small Ryobi high speed. +++ #4155 From: "Donald Schindler" Subject: Re: [Bearhawk] Safety with fiberglass cutting discs I dont think it would be over-kill to maybe call a physician and mention your experience. You say your throat is sore but the real problem might be a little deeper in your lungs. Repeated exposure to fiberglass dust will certainly bring on emphysema but this is the first time for you right? Maybe an over the counter expectorant might help bring it up. Guard those lungs and eyes. +++ #4156 From: BruceAFrank@a... Subject: Re: [Bearhawk] Safety with fiberglass cutting discs It is a good idea to protect your lungs from fiberglas dust. Any particulate can cause problems, but we are not talking Asbestos or Berilum (sp?) here. Fiberglas particles are moved out of the lungs fairly well over time with no real long term impact. The throat irritation could easily be from the powdered epoxy binder used to make the wheel. If you breath through your nose you'd be surprised at how little of such particulate actually gets to your lungs. I am not saying don't take care, but there were no real long term problems created during this one incident. Oh, I consider aluminum dust MORE of a hazard because of its reactiveness and its oxide crystal structure. +++ #4229 From: budd davisson Subject: Re:variations on explosive forming Re: alternate forming techniques In my one and only regular job since graduating college, for a couple of years I was based at the duPont lab in NJ where, among other things, they/we developed explosive cladding, which is how the original billets for laminated quarters (coins) were made, and we did some explosive forming. Most of this was done with Detasheet (spelling?) which was a sheet form of primacord. They did some really neat stuff, including forming one inch steel plate for boiler ends, but I haven't heard anyting about it since then. Incidentally, this was all done under water which provided much of the needed resistance to direct the explosion. Another method, I haven't heard anyone mention lately, is directly applicable to homebuilts. I once saw cowl bumps being formed via a unique method: rather than pounding them down into a female mold, a steel plate was screwed to the mold capturing the aluminum sheeting under it. The plate had a grease zerk screwed into it and then grease was simply pumped in via a normal grease gun. Enough pressure was developed to push the aluminum, without hammer marks, into the mold. They had an secondary method in which the sheet was trapped between two steel plates, one with the cut out of the part to be made, and they simply blew it up with grease, like making a small free blown canopy but in aluminum. Very cute method! bd +++ #4232 From: "Kent White" Subject: Re: [Bearhawk] Re:variations on explosive forming Detasheet is used by artists, still. One gal, down in AZ back in '90, was forming 5'X10' cor-ten a half inch thick using the stuff, and the female was a concrete bas relief. Took her a while to find the finished part, but that is why she used the desert for her workshop. Grease-gun forming, either free or captured is widely-known amongst older airplane folk. Our video on Fluid Forming is a variation, and uses a cheap pressure washer to inflate various-sized stainless, copper, aluminum, and steel sections for art, aircraft, and murdercycles. Rohr and GenDyn used to use electro-hydraulic forming, where an aluminum wire in a water column was fired by a huge bank of capacitors. Charge the caps, jolt the wire, shock wave goes through noncompressible "dolly" and the wave forms the part. Ka-Whoom! Explosive forging will do heavy sections in exotic alloys (Renee 41) with much finer detail and weight-savings than other slower methods. Cylinders and tubes may be bulged and contoured without having to withdraw complex interior die sections. Multiple metals may be formed together and sealed pressure tight without welding operations. If using water, there must be air between the dies and the blank to avoid weird displacement problems. Standoff is important. ---And always use a neighbor's pool. The water spout is a fine spectacle, but can empty the pool, and leave the condition of the bottom exposed to scrutiny. +++ # 4249 From: Russ Erb Subject: A truly useful but cheap tool At some point in your construction, probably after finishing your ribs and spars, you'll need to start laying out a bunch of stuff. This involves drawing a whole mess of lines. Just like when you were in school, this will require copious use of a straightedge. I got my most useful and favorite straightedge quite by accident. It started out life as a leftover strip of 0.025 aluminum from making blanks for the rib stiffener angles. Thus it is a little over 1 inch wide and about 3 feet long. It was cut on a 4 foot shear, so I know the edge is straight. I have used other straightedges, of course. When I've needed something shorter, I've used the 6" or 12" rules from a couple of combination squares. For really long lines, I've used an (aluminum) 4 foot drywall square. On occasion I've also picked up a piece of fuel tank strap (1" x .025 4130 steel). So why is my favorite my favorite? Two reasons: 1. It's flexible, so it will bend with the surface of the wing, such as drawing the centerlines of the ribs on the wing skin while the skin is on the ribs. The rules from the combination squares are stiff and won't bend (more than once). The drywall square is too unwieldy and heavy for most jobs. 2. (The main reason) For reasons I can't fully explain, any steel rules (or the steel straps) are hard to slide on the aluminum sheet to get in just the right position. My best guess is that the edges are trying to dig in to the aluminum, and the aluminum is just gummy enough to catch the edge. In contrast, the aluminum straightedge slides into position very easily. Much nicer. I also took a similar piece of aluminum and bent it around the same pipe I used to form the leading edges. I use this one to draw lines around the sharp corners near the leading edge. My recommendation to you is if you find access to a shear to cut the strips for your rib stiffening angles (check with local air conditioning contractors if all else fails), cut a few extra strips while you're at it to use for drawing later. Costs next to nothing; has benefits in excess of many expensive tools. +++ #4259 From: Corky Scott charles.k.scott@d... Subject: Re: [Bearhawk] Digest Number 260 > My recommendation to you is if you find access to a shear to > cut the strips for your rib stiffening angles (check with > local air conditioning contractors if all else fails), cut a > few extra strips while you're at it to use for drawing later. When I needed to cut a bunch of aluminum in straight lines, I used an old trick from I don't know where. I can't even tell you what gave me this idea but it did work. I laid the sheet out on my thinly carpeted floor and laid a long stiff straight edge on it and then used a very sharp carpenters knife to score the line. I did this very carefully the first several passes, digging in hard the second time. Then I made several more passes along the scored line pressing as hard as I dared. I flipped the sheet over and using the same stiff straight edge, laid it along the scored mark which was obvious from the indent I could see on the backside of the sheet. Then I was a matter of bending it back against the straight edge as I stood on it. The sheet gave right as the score mark and rocking it back and forth caused it to fatigue along the line. This left a lot of filing to do to clean up the edge but when you don't have the right tool (wide sheet metal shear) labor is cheap. +++ #4430 From: Bob Romanko Subject: Other: Nice Micrometer Set on Ebay Not mine, I already have a 0-6" ST set. I REALLY like Scherr-Tumico micrometers, and noticed this set on eBay ending at around 1700 EST today, January 8th. http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=535451895 The set new is around $700. I have no interest in this set, but thought fellow Bearhawkers may want to be aware. I like these more than those from Starrett or Brown Sharpe. +++ #4481 From: budd davisson Subject: Re: [Bearhawk] media blasters Re: Small parts blasting Somewhere I saw the plans for a homemade blasting cabinet built around a siphon blaster. It seems to me they were being sold by TP, the same folks who make a wide range of blasters and cabinets. They have lots of neat, applicable stuff, www.tptools.com. +++ #4487 From: "DANFORD, GARY" Subject: RE: [Bearhawk] media blasters I have been working on cars, pickup's, lawnmowers and airplanes for years and don't see how you can get by without a sand blaster. Your welding immediately gets better because you don't have to weld thru slag. The sand blaster takes the surface tension from welds and the paint sticks. I would suggest[http://www.tptools.com]. They sell a sandblaster kit with plans for the cabinet for around $149.00. The cabinet requires 2 sheets of plywood and you're in business. Mine works great and wouldn't be without it. You can also call them at 1-800-321-9260. +++ #4548 From: Russ Erb Subject: Re: [Bearhawk] media blasters > Cooling plenum? do tell! I've had a real problem with water > while painting and I'm willing to try anything to fix it > (short of hiring out the process ;-). I figured someone would bite on that phrase. Ken, it's a fancy name for a fairly simple concept. When I lived in Colorado, I had the air compressor in the garage (noisy damn thing) with the air piped down to the basement. Originally I had the filter/dryer (the thing that looks like it has a gascolator bowl on the bottom) all of 18" from the compressor. In several years, I never saw any water trapped in it. Granted, Colorado Springs is drier than a lot of places, but not that dry. I moved the filter/dryer to the basement so that it was about 8 to 10 feet from the compressor. Hmmm...now I'm starting to pick up some water. My theory is that the air coming out of the compressor tank is still warm enough that the water won't condense out. Solution: Give the air some time to cool down before getting to the filter/dryer. Therefore, my "cooling plenum" is about 40 feet of 1" Schedule 40 PVC pipe zig-zagging downhill (to drain the water) before getting to the filter dryer. Granted, now I live in the desert, but I occasionally do pick up a little water in the dryer, so I'm guessing it's working. All of this is kind of meaningless for painting since I'm using water-borne Poly Fiber products... For those of you who may be horrified at the thought of using PVC pipe for compressed air distribution, we've already had that discussion. Go see the archives or the CD. By the way, the system is also grounded by a galvanized wire inside the pipe connecting the brass fittings at the ends and grounded. At least it was when it was built--I have no idea what condition the wire is in now. +++ #4562 From: Ken Beanlands Subject: Re: [Bearhawk] media blasters Don't be fooled in thinking that a slug of water does not affect the AFS water-borne stuff. That is exactly what I painted the fuselage and tail surfaces of the Christavia (and what I plan to paint the Christavia wings and the Bearhawk) with. Fantastic stuff. However, if you get a slug of water (it always seems to come in a slug whrn you disturb the hoses or change the spraying orientation) will need to be blotted off with a rag or it will leave an unsightly run in your paint job. It doesn't seem to affect the CecoFil that much, but it definitely hampers the paint. Back to your plenum. Where are your inlet and outlet with respect to the plenum? I've seen "Drip lines" where the pipe runs from ceiling to floor but the outlet tees off about half way down. +++ #4583 From: Russ Erb Subject: Re: [Bearhawk] media blasters > Don't be fooled in thinking that a slug of water does not > affect the AFS water-borne stuff. I wouldn't doubt that, since it would be like a slug of primer in solvent based paints. My point was that a little extra humidity was not going to affect it like, say, it would dope. > Back to your plenum. Where are your inlet and outlet with > respect to the plenum? I've seen "Drip lines" where the pipe > runs from ceiling to floor but the outlet tees off about half > way down. Can't get past this one...The hose from the compressor goes almost straight up about 18" to the beginning of the plenum. The pipes zig-zag downhill almost to the ground. One leg of a pipe tee goes to a standard female "M" style connector. Stuffing a male connector fitting into it blows the water out of the lowest point. The other leg of the tee goes into the garage and straight up about 3-1/2 feet to a manifold with two regulators and an unregulated outlet, all connected to female connectors. Come on down and see it! +++ #4611 From: bearhwk272@a... Subject: Tank testing and glue Couple quickies. Glue, I use quite a bit of particle board, MDF and chip board for tooling and fixtures. Found a new to me glue this past week that works great. It is Elmers exterior waterproof white glue. Duh,what's the big deal? It is in a new format..... a gell.... like toothpaste. Does not run, works well into the pores of the material makes nice edge fillets, cures out much stronger than the other glues I had used, much faster drying. +++ #4745 From: Benton Holzwarth Subject: Fluting pliers (was: Building Status #426) > Currently I am attempting to make the flutting pliers. I > haven't bought a real tourch yet, so I'm working with a little > map gas set. It seems to be having trouble getting the pliers > up to the right temperature. If I don't work out a solution > soon I will probably just buy a pair of flutting pliers and > get on with the work. I'm just a little ahead of you, and will share what I thought worked for me. I started by filing a healthy nick onto each side of the jaw, a'la a center-punch mark, then clamped the jaws, still pinned together, into the vise. I also had trouble getting the hole drilled out. When it finally worked, I'm not sure it was heat that did it, but maybe that I'd been trying to drill with a relatively small bit -- say about 3/16" [meant to say 3/32" bjh] or 1/8" -- expecting to work my way up. I finally gave up, and switched to something closer to the full 1/4" and it did finally bite in and go without too much trouble. (I had applied heat from a small O/A tip, before and during the earlier drilling with no greater success than when cold. I cut the piece of 3/16" rod to length and layed in the groove, for brazing. Doing it again, I think I'd try leaving the whole length of the rod attached, to aid in getting the bit straight. Mine's a little crooked. Having never seen a store-bought set of fluting pliers, it wasn't clear to me just how polished they really want to be. I thought I'd done an appropriate job of shining 'em up, and was merrily flanging and fluting away on my ribs, when doubts began to crop up. After an exchange with P-Bob, I've scrapped my first dozen ribs, and started in on my second first-dozen. The pliers, as originally finished, were leaving nicks on one side of the metal, and a frosty mark on the side against the rod. I believe the nicks were probably salvagable, but the sanding and polishing marks were so gross that I just couldn't let these be my first airplane parts. Here's a scan of a sample flute from the 'before' pliers: http://www.teleport.com/~bcgh/jpegs/d9.jpeg [now http://www.siletzbay.com/Images/d9.jpeg BJH ] Also, the nicks suggest that the metal was holding there, rather than sliding, indicating that I was stretching the metal, rather than pulling in a bit to form the flute. After more work with a file -- rounding the female jaw side and rounding the toe off the rod; and then working 'em over with a Scotchbrite wheel (which moved a lot more metal than I was expecting) and polishing with emery-cloth (fold a strip so it's grit on both sides, clamp lightly in jaws and clamp in the vise, then run back and forth like dental floss) -- they looked pretty good. Then I hit 'em with the Dremel-mounted buffing wheel to put a high shine on 'em. (The 6" wheel just wouldn't get into the tight spots well.) A trick for the Dremel tool -- I got some grocery-store Scotchbrite pads -- the 1/4" thick green stuff. Traced around a coin to make circle and cut out with an Exacto knife, and mounted in the little mandrill that came with the tool. At mid-speed they make good little abrasive wheels. Less agressive than the grinding stones, more than the cotton pad. Don't last too long, but only take a couple minutes to cut out a half dozen, and a moment to change. +++ #5002 From: Budd Davisson Subject: Re:Beading roller I know a bunch of you probably already know about this, but I've finally bought a cheap tool that works, at least for the time being and I thought I'd pass it along. I just bought Harbor Frieght's hand beading roller, SKU S34104, $170 and just ran a bunch of 18 gage cold roll steel through it (the trunk floor for my roadster). It works like a charm. A Chinese charm, since it has Made In China stamped in so many places it'll eventually fatigue crack through one of the "I"s. It comes with three different size of beading rollers and three different flanging dies. All work well. Okay, I know some of you are frowning that I'm trading with the Chinese. Especially my partner. However, look at it this way: If we buy enough of their stuff, we'll represent enough of their market that they can't afford to nuke us. Of course, that assumes some sort of logic reigns at the higher levels, which I'm afraid may not be the case. So, I'll just bead the top of my fall-out shelter a little more to ride out the attack. Just passing it along. This would be trick for the gas tanks. PS I just ran some .032, 2024-T3 through it and it acts as if there's nothing between the rollers. +++ #5003 From: "Bill Cox" Subject: Re: [Bearhawk] Re:Beading roller That is the tool I used to bead my tanks and it works great. +++ #5005 From: "Tim Anderson" Subject: Re: [Bearhawk] Re:Beading roller Harbor freight had that model on sale last month for something like $120. Almost bought one. +++ #5009 From: Mark Deacon Mark_Deacon/MSP/Mesaba%Mesaba@M... Subject: Re: [Bearhawk] Re:Beading roller A friend of mine has a beading roller his dad used back in the "good old days". I was wondering if you could use it to bead the ribs instead of bending/cutting/drilling/deburring/riveting a gozillion angles on the ribs? P.S. Are there any Bearhawk builders in shootin' distance of Detroit? +++ #5011 From: Budd Davisson Subject: Re: [Bearhawk] Re:Beading roller This is an interesting question. At some point a bead will equal a riveted stiffener, but, for the life of me, I don't know how to calculate the differences. I spoke with BOB about it one time and he was skeptical. When we get everything up and running, I think we'll do an empircal comparison. Make one each way and put them in a loading jig to seewhich is stiffest or how much of a bead it takes to equal a riveted angle. It would certainly make life easier for all of us, if those little stiffeners were eliminated. +++ #5020 From: Tim Subject: Stiffing Beads...pics & tool pic I've uploaded a few pages from my 2 Pazmany Builders Manuals.....These will download automatically in just seconds, from where you sit ;-) NOTE: Pazmany doesn't use fluting pliers, he files notches in his form blocks #1....Edge radis table and how to make tool... #2....Shows Beads in wooden form blocks and even a lightening hole die #3....Shows an Aluminum beads die block....Lightening hole die +++ #5021 From: Budd Davisson Subject: Re: [Bearhawk] Re:Beading ribs Re: beading procedure I think the beading could be done while the blank is still flat, you'd just have take a round nosed bit in a router and cut clearance grooves in the form block. I'd bet you could flange the ribs and do the hole flanging with dies (me and Bob-sticks don't match) and have no problems. None of this makes any difference however, because we don't know if this is a structurally sound alternative and won't until we investigate it through testing. The Bob won't let it go through any other way and he's got go, no-go approval power over the production aspects of the kit. +++ #5052 From: "Kent White" Subject: Re: [Bearhawk] Re:Beading roller > This is an interesting question. At some point a bead will > equal a riveted stiffener, but, ..." Trust me on this one guys: Beadforming hardened material will get you distortion...only. +++ #5055 From: "Tim Anderson" Subject: Re: [Bearhawk] Re: lightening holes I have been using a Rotozip tool lately to auger out my larger fuel tank holes and it works well....But it can get away from you real quick. For those that don't know what a rotozip tool is, it's basically a smaller, hand-held router with small streight bits. I didn't use this on my lightening holes, I used a hole cutter on my drill press and then bob-sticked. But, the rotozip has it's uses. Should be able to see one at Home depot if your interested. $60-$70 range as I recall. +++ #5093 From: Rob Gaddy zipppydoggg@y... Subject: Re: Malco > I'll add my experience with the malco and flycutter operations > to the discussion. I've had excellent results with mounting > my router to/under my work table. As mentioned, I used the Malco and didn't like the precision of the hole size, or the finish on the inside of the hole. More time was required to smooth the inside of the hole. I mounted the fly cutter to a drill press (don't even think of trying to use a hand held drill with a fly cutter) and after setting up for a particular hole size, I set up the clamps and was able to "drill" all the holes is short order, with precision and good quality hole finish. When setting up for the next hole size, sharpen the cutter ;-). By the way, the belt on my drill press is "way loose", I highly recommend this since the belt would slip when I did something stupid. The cutter would just stop and then I could stop the drill press motor, get unstuck and then proceed again. I cut my rib blanks, without lightening holes, flanged and straightened them, then drill the lightening holes. It worked, nothing sayes that the lightening holes couldn't be accomplished with the blanks are cut, but the lightening hole centers were used for index pins during the flanging operation. Snowed in Phoenix again +++ #5127 From: Budd Davisson Subject: simple revelations Second revelation: I was looking for something to protect the weld table under a weld and grabbed a apiece of scrap 20 gage steel I had been using to learn how to use my new Harbor Frieght roller. The piece had a couple of beads rolled in it, which acted like feet to keep the metal off of the table top. Again, worked great! I then took a 6" quare piece of 20 gage and rolled a bunch of parallel beads about 1.5" apart to use as a ready-made stand-off for holding stuff off the bench so I can weld it. The best stuff is always the simplest and the most obvious. Duh! +++ #5241 From: Budd Davisson Subject: Re:Tinman Video This is an unpaid for, unexpected and unsolicited review. The subject is Tinman's (Kent White) new video called Those Darned Saddles. The only thing about the tape I didn't like was the title. The rest was terrific and much of it is directly applicable to Bearhawks. The tape gives a blow by blow (pun intentional) account of how to make first, a windshield fairing strip out of aluminum and then a strut-to-wing cuff. First a side note for doubting Thomases: there's a general feeling that the ability to form compound parts out of aluminum is black magic. When it comes to big parts and subtle panels, that's right. But, wheni t comes to smaller parts like these, it is absolutely achievable by anyone. I spent many weeks down at Jim Younkin's watching him make similar parts and I was amazed how quickly I picked up the ability to do these kinds of small parts. More important, I was amazed at how much more quickly they progressed than fiberglass. In the time it takes the average guy to first locate the foam for a mold, glue it in place and then get ready to shape it, he would have the aluminum part done. One great aspect of making aluminum small parts is that when you make a mistake and have to start over, you only have a maximum of 10-15 minutes tied up in it and you're perfectly willing to make a new piece. Now to Tinman's video: The windshield fairing strip he was making was quite simply a matter of understanding where to stretch it and where to shrink it, all of which was done with a funky looking square mallet and an easily made steel dolly (make out of pipe). I can't wait to try it myself. Kent spends a fair amount of time showing how to make the patterns, understand what the patterns are telling you, and then how to make the part. very cool and fairly easy. The wing cuff, which would go up at the top of the strut, is made of two pieces and he shows several different ways to make it. The inside portion, with the tight "saddle" (hence the video name), is the tough one, but again, its a matter of making a pattern and seeing what it tells you about where to shrink and stretch. Making this part will produce some scrap, but I'm willing to bet that every builder reading this will spend an evening making scrap, think about it the next day, and the next night will make a useable part. Kent was welding his halves together, but they could be butted and flush rivetted just as well. This a video worth watching, as it also includes making wing to fuselage fairings, as on low wing airplanes, but which we don't have to worry about on the BH. I also bought Tinman's starter kit for aluminum welding. I haven't gotten into it yet, but I'm planning on doing an article, for Airbum, if no place else, titled something like Country Klutz Tries the Impossible: a Study in Learning. Stay Tuned. +++ #5242 From: Jim Ash Subject: Re: [Bearhawk] Re:Tinman Video For those at the Sun 'n Fun: Go to the hand-forming tent and spend a half hour or so with a shot bag and some mallets and dollies. Once I got the basic principles, I found it pretty easy to form up a part. If you're going to work with sheet metal, this skill is a must-have, as well as being a lot of fun. +++ #5667 From: WAYNE ESTMENT Subject: LASER CUTTING Does anybody know if laser cutting 2024 T 3 sheet will cause any cahnges in amterial strength due to the heat of the laser. Wayne +++ #5668 From: hkeil@n... Subject: RE: [Bearhawk] LASER CUTTING there will be a heat affected zone along the cut. It will probably not be too wide in thin sheet. Have you considered water jet cutting? No heat affected zone, easier to deburr, you can stack the sheets up to one inch thick for ribs and such. Herman Keil (lurker) +++ #6229 From: Russ and Penny Erb Subject: RE: [Bearhawk] air compressor Compressor: Depends on your tools. Rivet guns won't stress it, and air drills aren't that bad. Check flow rates on spray guns and sandblasters. +++ #6235 From: Budd Davisson Subject: Re: [Bearhawk] air compressor Air compressors: sand blasters are the real air-eaters. Ditto cut off wheels. Figure a mininum of 5 horsepower, 30 gallon tank, 7 cfm at 90 psi. 7 hp, 40 gallon is better. $500 will buy more air compressor than you can use. it'll be 220 AC, by the way. bd +++ #6236 From: Bob Romanko Subject: RE: [Bearhawk] air compressor Here is a response I made to someone thinking that only a 2-stage compressor would work for aircraft construction. I posted it on RAH: A 2-stage compressor required for aircraft building? This is pure Barbra Streisand (BS). A single-stage compressor will do you just fine assuming you buy a big enough single-stage. I have a Porter-Cable that is a 220V motor on a 60 gallon vertical tank. It's right around 9.6 CFM at 90 psi. That keeps up nicely with a 4000 rpm drill motor, and dies of boredom with anything else I have. Harbor Freight now sells several compressors with close to the same specs for less than $450 USD and free shipping in the continental US. I paid $410 for my Porter-Cable, and have been totally thrilled with it. With these larger single-stage compressors you're talking belt-driven, twin cylinders. DO NOT GET A DIRECT DRIVE "OIL-FREE" COMPRESSOR! If you think I'm shouting, wait until you plug one of those babies in. If in a confined space, quite possibly the loudest sound you'll ever hear. For what it's worth... Planter Bob +++ #6239 From: meldredge@a... Subject: Re: air compressor > you're talking belt-driven, twin cylinders. DO NOT GET A > DIRECT DRIVE "OIL-FREE" COMPRESSOR! If you think I'm > shouting, wait until you plug one of those babies in. If in a > confined space, quite possibly the loudest sound you'll ever > hear. what? WHAT?? DID YOU SAY SOMETHING??? MY DIRECT DRIVE OIL-FREE COMPRESSOR IN THE BACK CORNER OF MY GARAGE JUST KICKED ON. Yes, it's $#(*& loud. I have to remember to shut it off at night just so it doesn't pick an inopportune time to re-fill itself and wake the neighborhood. It was inexpensive, though. $230 or so at Sam's Club -Mike (wearin' ear plugs) Eldredge #427 +++ #6245 From: Ken Beanlands Subject: Re: [Bearhawk] Re: air compressor The other two disadvantages that were brought to my attention (may or may not be true) were that the oil-less compressors will eventually wear out thier bearings (usually some sort of synthetic material) and will need replacing. If the company is out of business, you may have a disposible compressor. Granted, with the amount of use that we amateurs give it, it would probably last our lifetimes. With proper maintenance, the oil type last a lot longer. The other thing was that the belt drive compressors can be replaced in a modular fashion should something fail. Say, for instance, the pump failed. You could truck down to your local compressor repair shop and buy a refurbished pump from another vendor, make up some mounts for your tank to accomadate the new pump and slap on a new belt and pulley to fit and away you go. Same goes for the motor and for the tank. With direct drive units, you are far more dependant on finding exactly the right motor and pump as they are bolted together as one unit. However, as Mike pointed out, you can generally get 2 Direct Drive Oil-Free compressors for the cost of one oiled, belt drive one. One other thing that was suggested was to look for a compressor with a cast iron head rather than aluminum as it disipates heat better and is less prone to fatigue cracking. I ended up with a Campbell Hausfel (sp?) 4.5 HP belt driven, oiled, iron headed compressor for about $450 CAD ($300 USD). It's OK for most things but a little small for an HVLP spray gun. I've been using it anyway but I might try and get a bigger, or just a second compressor for the wings. BTW, can anyone see any problem in hooking up two compressors in parrellel to try and get enough flow to spray the plane? I'm sure I can find someone else in the area that will need to spray a plane that I can work out a deal with. (I borrow his and he borrows mine) Just some food for thought. Ken Beanlands B.Eng (Aerospace) +++ #6247 From: zipppydoggg@y... Subject: Re: air compressor > With proper maintenance, the oil type last a lot longer. > > I ended up with a Campbell Hausfel (sp?) 4.5 HP belt driven, > oiled, iron headed compressor for about $450 CAD ($300 > USD). It's OK for most things but a little small for an HVLP > spray gun. I've been using it anyway but I might try and get a > bigger, or just a second compressor for the wings. > > BTW, can anyone see any problem in hooking up two compressors > in parrellel to try and get enough flow to spray the plane? > I'm sure I can find someone else in the area that will need to > spray a plane that I can work out a deal with. (I borrow his > and he borrows mine) I have an old (20 years) craftsman 2 horse with 20 gal tank (iron head, belt drive, etc.). It is OK, and has lasted a long time. It is not big enough for large sandblast jobs, but can generally keep up with a conventional spray gun. One thing I did is add an automotive air filter to keep the grip out (sandblasting) and replaced the air line from the compressor to the tank with a long length of copper tubeing, made into a coil, to reduce the temperature of the air going into the tank. I don't really care what temperature the tank is, but the unloading valve is mounted at the tank, and was getting overheated (causeing sticking) with the short stock length tube. All that said, I think there is a better way. I would suggest that it would be better (cheaper) to buy a small 110V unit for general low volume shop work (drilling, riviting). This unit is also portable so can be used to air up the RV tires in the back yard, etc. When sandblasting and (to some extent) painting is needed, just rent a gasoline engine compressor from the local rental agency. Lots of volume. These units by definition are portable and allow you to sandblast somewhere away from the shop and house (dust). This is what I would do if I started over. (I've been waiting for the Sears unit to die for about 10 years now). OK, it is better to have to tools on hand in the shop, so if the pocket book allows, one big unit for the big jobs, and one small unit for portability. As was pointed out, the volume of the tank is important. The bigger the better. Any extra tankage is good. By the way, I wouldn't see any problem hooking up two or more units togeather. It would take a couple of "T's" (parallel). You could run one unit into the other's tank. I would think you would want to keep the hose length to the spray gun/sandblaster unit to a minimum length. Advice is worth what you pay for it. Rob $.02 Gaddy BH 401 +++ #6255 From: Russ and Penny Erb Subject: RE: [Bearhawk] air compressor WHAT? JUST A MINUTE, LET ME TURN OFF MY DIRECT DRIVE "OIL FREE" AIR COMPRESSOR... And where, Planter Bob, do you recommend I get a belted, oiled compressor? When I look at Sears, they ain't got 'em, and when I do find them, they cost way more than the noisy kind. I have one of the noisy suckers (or would that be blowers...) that lives outside the garage and is plumbed in. Keeps the noise down to a reasonable level. It's been running (off and on) since I bought it in 1995. However, when I move I'll probably have to have the compressor, er, noisemaker, in the hangar with me. My brother and I are working on an idea for a soundproofing enclosure that would let the air in, allow a flow of cooling air, allow easy access, but keep most of the noise in, or at least enough that I don't jump out of my skin when it comes on. Seems a viable option is to buy the cheap LOUD compressor then soundproof it, and buy another one when it dies. Russ Erb #164, Edwards CA +++ #6261 From: Jimmy Mathis Subject: RE: [Bearhawk] air compressor Do ya'll have any Grainger's outlets where you live? I bought the tank and a compressor head and motor to customize my setup to what I wanted and spent around $300.00 Jimmy +++ #6262 From: Bob Romanko Subject: RE: [Bearhawk] air compressor Del, you're warm with the Porter-Cable, but don't get the BIG one. It's a two-stage unit, sits on an 80 gallon tank (I think) and is way overkill. Get the smaller one on the 60 gallon vertical tank. It sits there at 135 psi all the time and I put a separator and regulator on it to get it where I need it. I don't bother with oilers, as they just muck up the lines and create the hassle of keeping your hoses straight when painting. I just put a few drops of Marvel Mystery Oil directly into my tool inlets. Planter Bob +++ #6263 From: Bob Romanko Subject: RE: [Bearhawk] Re: air compressor You DO have yours mounted to a concrete slab, right?!? I secured mine with 5" x 3/8" lag bolts and the rubbers dampers with steel cups that came with my compressor. You'll have vibration in most cases because you tighten the nuts too much and compress the rubber and they're no longer effective. What I did that worked well was to tighten down the nuts, fire up the compressor, then gradually loosen the nuts (evenly) until the vibration was minimal. Planter Bob +++ #6264 From: Bob Romanko Subject: RE: [Bearhawk] air compressor Okay everyone, here's the URL to my compressor: http://www.porter-cable.com/cgi-bin/products.cgi?method=byid&prod_id=CPLC7060V Sorry for the long URL. I bought this unit at my local Lowe's store for $429. I could have got it at 10% off if I waited until the ONE day a year where they have a "10% Off Everything in the Store" sale. I'm not that cheap, so I bought the silly thing when I needed it. (Now this past 10% day I DID buy a fourth (for me) compressor, a Senco, to run my Paslode framing nailer. Can't have too many toys, you know!) Anyhow, this is a darn good compressor, folks, and I looked for about six months comparing specs. I like Porter-Cable, although chances are REAL good the didn't actually make this thing. There's a good chance this is a slightly tweeked Coleman, which I have no problem with. They make a good compressor as well. If you don't want to click on the URL, here are the specs "Cut and Pasted" from the website: Compressor, Model #CPLC7060V 7 HP(peak), 60 gallon stationary oil lube compressor vertical tank 220 Volt induction motor with manual thermal overload protection Higher operating pressure for more work. 110 PSI start and 135 PSI stop High output of air: 12.1 SCFM @ 40 PSI/9.7 SCFM @ 90 PSI Cast iron cylinder sleeves Pump contains automotive style pistons, rings and connecting rods Large tank pressure guage Full-size belt guard Patented automatic belt tensioning device CUL listed with ASME constucted air tank and safety valve to meet codes I think these are pretty good for the price. Most HVLP guns need 8cfm/60psi, so this thing would keep up nicely. It makes it easier when the tank is charged to 135 psi and you use 3/8" hoses and regulate it down off the tank. For what it's all worth... Planter Bob +++ #6268 From: "Tim Anderson" Subject: RE: [Bearhawk] Re: air compressor Painting does take some air, but also, it depends on your painting style and what your painting. When my brother was painting his lancair, he thought he would need a big compressor (220V) and a big capacity gun. Turned out that a lot of peices were small enough in size that he didn't run the gun a lot in constant "spray mode". When I did my kitfox, the wings were easiest, but took a lot of constant air supply. My oil free direct drive 3.5Hp unit struggled a bit but it worked. I had to plug it in without use of an extention cord to reduce the power drop in the cord...and use a long hose..requireing more air pressure to make up for hose drop by the time it reached the gun. Poly tone is easy to work with. Moving around every two to four years and renting houses prevents me from installing any equipment in a permanent mode and installing 220V circuits in my CAVE..(workshop). Tim #398 +++ #6281 From: Jim Ash Subject: RE: [Bearhawk] Re: air compressor Slab? Concrete? It came bolted to a pallet. I leaned it into my van and slid it in on its side. When I got home, I pushed it out and stood it back upright, pallet and all, then pondered how I would, alone and sans any kind of lifting device, get it into the garage. I started rocking it sideways, and used this rocking motion to 'walk' it into place. I pulled 220v service to a switch box on the wall and flex conduit to the compressor. There it sat for 10 years and many hours of service until we sold that place. It's similarly placed in the rental house I'm in now. You mean my house doesn't have to shake? Jim Ash +++ #6308 From: Budd Davisson Subject: Re: [Bearhawk] air compressor My two cents on dry air. For a couple of decades I painted and sand blasted in northern NJ (during a protracted period of temporary insanity) and had a terrible time getting air dry enough to keep blasting and painting. Finally i went the entire route with the enclined metal airsupply line on the wall and all that. What worked best, however, was overkill in the clean-the-air-line department. I got two oil/air separators and two moisture coelessors from TP Tools (www.tptools.com) and piped them all together in a little unit that mounted on a foot square skid with air jacks on both sides. When I wanted perfect air, I just jacked the long line into the unit and a shortline to the gun or sand blaster on the other side. Never an an instant of trouble after that. bd +++ #6746 From: "Donald Schindler" Date: Wed Jul 4, 2001 6:24 am Subject: Re: Erbman's possibly useful trivia... Russ, Congratulations on discovering valve lapping compound. You will find that it will be a most useful friend to you. I carry a can in my toolbox that has both the course and fine in two separate compartments. An old mechanics trick is to dip your phillips head screwdriver into the fine compund to use on the screws you think will be stubborn, then use lots of pressure and it'll hold like a rabid dog. I take off lots of spinners and it sure is my trusty friend. Soldier on... Don 068 +++ #7168 Date: Mon, 13 Aug 2001 11:23:20 -0700 From: Benton Holzwarth bcgh@ Subject: engine-mounted compressor (was: semi OT: Tools) > Some of you on this group might be interested in the portable > compressor setup I want to eventually install on my Jeep. You > take a regular A/C compressor, run it off the engine with a > belt (like in the A/C setup)... Perhaps you could find someone taking the airstart off their M-14P setup? I'm presuming they have an engine-mounted compressor to refill the bottle... Benton 13aug01 +++ #7170 Date: Mon, 13 Aug 2001 10:29:00 -0800 (AKDT) From: Float-By Shooter del@ Subject: Re: engine-mounted compressor (was: semi OT: Tools) > Perhaps you could find someone taking the airstart off their > M-14P setup? I'm presuming they have an engine-mounted > compressor to refill the bottle... Actually nothing that exotic is needed; most guys just get an AC compressor from a junkyard and adapt it as needed. Del Rawlins-- +++ #7173 Date: Mon, 13 Aug 2001 15:14:59 -0700 From: "Owen Davies" owen@ Subject: Re: engine-mounted compressor (was: semi OT: Tools) > Actually nothing that exotic is needed; most guys just get an > AC compressor from a junkyard and adapt it as needed. That's an interesting thought. Any idea how much pressure and volume they can put out? How do they compare with a refrigerator compressor? Thanks. Owen Davies +++ #7175 Date: Mon, 13 Aug 2001 13:41:36 -0600 From: mprather@ Subject: Fwd: Re: engine-mounted compressor (was: semi OT: Tools) I think the M14P compressor is designed to have about 700psi. Its a pretty monster pump, from what I have read. This is an exerpt about the engine. "Some tips about the pneumatic system Quite a few flat-engine pilots have asked me how long the air reservoir will hold its pressure between flights. It seems to me that when my head wrench gets all the leaks chased out of the system, it really doesn't leak at all between flights and would be capable of holding its pressure for months. It is true that if you fly, put the airplane away, and see, for example, 700 p.s.i. on the gauge, you might see only 650 p.s.i. when you come back to fly the next day. That's probably because the air in the reservoir got cooler overnight, not because the system is leaking. There are a number of tender fittings, and with 800 p.s.i., it doesn't take much of a leak to let the pressure escape quickly. So you need to chase down the leaks and eradicate them. You will probably need to put " Matt- +++ #7178 Date: Mon, 13 Aug 2001 19:35:50 EDT From: supermexgarza@ Subject: a/c compressor > Some of you on this group might be interested in the portable > compressor setup I want to eventually install on my Jeep. You > take a regular A/C compressor, run it off the engine with a > belt (like in the A/C setup)... Here is my 2 cents worth I been doing refrigeration for a living for years. both sationary and trailer sistems been familiar with automotive type compressors and they will not last more than a few hours( 2 o 3 ) of run time if used for an air compresssor, Before you send me any hate mail telling me that your next door neighbor`s cussin`s brother in law`s exnephew had one for years here is what is going to happen if an A/C type comressor is used on an open loop sistem open loop been ; the gas that the unit pumps is discharged in to the air and does not return to the intake, you will loose the oil in the compresossor very rapidly there are only 8 or 10 oz of oil un an automotive comressor. and they "spit" oil out of the discharge (that is a fact) even if it is"brand new", sinse the comp is used in an closed sistem in A/C the oil will allways find its way back to the comp. if you install an oiler in the intake and you do not use the comp in a regular basis the day you need the air comp (FLAT TIRE) it will have an exess of oil in the intake valve, the moment you energize the clutch it is good bye valves because the density of the oil you will break a thin metal call "reed" and you will have compresor that will not suck there for it cannot pump AT ALL un less you find an OIL LESS COMPRESSOR at WALL MART "baaaaut" 19.95 and it plugs in in the cigarett ligther saving the radiator when the compressor locks up and the belt comes out flying to get wraped around the fan blade and you wil have the most powerfull wed eater ever made sorry if i went long Javier (freon sniffing ,ozone killing we all going to die from skin cancer) Garza Hou TX # 497 +++ #7188 Date: Mon, 13 Aug 2001 19:23:25 -0800 (AKDT) From: Float-By Shooter del@ Subject: Re: a/c compressor > been familiar with automotive type compressors and they will > not last more than a few hours( 2 o 3 ) of run time if used > for an air compresssor, Before you send me any hate mail > telling me that your next door neighbor`s cussin`s brother in > law`s exnephew had one for years here is what is going to > happen Definitely no hate mail, I'm interested in learning as much as I can before I try to install something like this. I will say that I follow the rec.autos.makers.jeep+willys newsgroup, and there are a number of members who have had good results with their systems, but a lot seems to depend on the type of compressor used and how it is set up. I can't address your specific concerns because I don't know a whole lot about A/C (it hasn't been much of an issue here in Alaska). What I do know, from reading the experiences of people who have installed onboard air systems, that the compressor to get, is known as the "York." They were used on a lot of older vehicles, are common in junkyards, have their own built in oil reservoir, and pump the most volume out of the available A/C compressors. They are also the largest and most difficult to fit under the hood, and usually require special adapters. The other, easier alternative is the OEM rotary type (York uses a piston) compressor as would have been originally installed on a given vehicle for the A/C system. This neatly avoids the mounting issue (if you don't have A/C already and can find the right brackets at the junkyard) but introduces the issues of a less heavy duty unit, and the need for an external oil supply (since they would normally be lubricated by the oil in the refrigerant). One recent poster to the Jeep newsgroup described how he cooked his rotary compressor by overheating it filling up the tires of multiple rigs at the end of trail runs (since it is SOP for 4 wheelers to air down tires for better traction, at the end of a run if you have a fast compressor you become everybody's best friend). The 2 things that are really critical are th3e need for a "pop-off" safety overpressure valve, and a pressure switch to regulate the pressure. These compressors are apparently capable of generating a lot more pressure than is needed or desireable. They also produce a lot of heat and many users have had to go to hydraulic hose (standard air hose won't cut it) right after the pump to deal with it. There are, of course, a number of 12v electric compressor options, but they all share the common trait of being relatively slow, and even with an air tank (many use truck air brake tanks, and others plumb fittings into bumpers, nerf bars, etc) you won't be able to run tools for long, and may not be able to reseat tire beads. An engine driven compressor may also spit a lot of excess oil out the line and into the system, but that certainly won't do your air tools any harm, and it isn't like you'd be trying to paint with it. Most guys don't seem too concerned about compressor failure, since another trip to the junkyard for another cheap used compressor isn't a big deal (unless, as you mentioned, it dies when you need it). Del Rawlins-- +++ #7190 Date: Mon, 13 Aug 2001 19:54:40 -0800 (AKDT) From: Float-By Shooter del@ Subject: Re: engine-mounted compressor (was: semi OT: Tools) > That's an interesting thought. Any idea how much pressure and > volume they can put out? How do they compare with a > refrigerator compressor? The onboardair.com site has specs, but I couldn't find a CFM rating anywhere for the Yorks. And unfortunately I have no idea what a fridge compressor puts out. They do, however, have links to lots of people who have installed air systems on their vehicles. Del Rawlins-- +++ #7209 Date: Tue, 14 Aug 2001 08:29:39 -0700 From: "Greco, Bob" bob.greco@ Subject: RE: a/c compressor I used a York 2 cyl refrigeration compressor from a refrigerator truck. I powered it by a 1.5 hp electric motor and used it mounted on a five gallon air tank as an air compressor while building a MMII. Used it to run rivet guns, paint sprayers and rotary grinders. Worked great although sometimes the sprayer got ahead and I had to wait for it. It is still working today in a cabinet shop as their backup. That is almost 30 years of use as an aircompressor >>> 2mar02 #7686-9153 +++ #7743 From: "Kent White" Subject: RE: Hydraulic presses I have seriously bent the cheap orange presses using their own jacks at full capacity. The taper top design might eliminate the "bent into a hairpin" top beam. But the table adjustment holes will still elongate. Kent White +++ #7744 From: yeomans@s... Subject: Re: Cutting tube and Hydraulic presses When buying any tools you get what you pay for.. for just a few operations these presses are probably fine if you watch the pressure you apply.. As far as a tube cutter. I cut most of my tube to .049 and some heavier with a standard copper tube cutter from a deptment store. I don't like adding the concentrated heat that a cut off or chop saw applies... But thats only my opinion. weld on.. Tom Yeomans 075 New Mexico. +++ #7746 From: "Owen Davies" Subject: Re: Cutting tube and Hydraulic presses > Why not invest $60 in a 14" cut-off saw from Harbor Freight It's a whole lot more money, but folks might want to take a look at Ernie Leimkuhler's posts about cut-off saws that use a blade rather than an abrasive disk. Look for them in the Google archives of rec.metalworking and sci.engr.joining.welding. He makes them sound like really nice tools. Owen Davies +++ #7891 From: "Rod Smith" Subject: 18" Sheet metal tool I noticed this combination sheet metal tool on sale at harbor freight. I know that some of you had mentioned a beading tool from harbor freight previously. What do you guys think, hopelessly cheaply built? http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=34104 Rod Smith #246 +++ #7893 From: Budd Davisson Subject: Re: 18" Sheet metal tool I have their beading tool and it works well, but you need to polish the edges of the female die or it leaves marks. I have their 24" break and it doesn't have enough clamping pressure to bend anything but the thinest stuff. You can modify it fairly easily to keep the top piece from sliding back. bd +++ #8341 From: "Bruce A. Frank" Subject: Budd, Thank You! A few months ago you recommended a sand blast outfit manufactured by Truman Company (The San Blast model). For those who don't know or remember it is a pressure feed, rather than siphon feed, unit that holds about 100 lbs of sand. I had been fighting with a Harbor Freight siphon feed unit for 15 years. Between the constant clogs from condensation and grit irregularity and the low velocity low volume flow and a compressor that couldn't keep up I farmed everything out. A week ago I built myself a new engine mount for my 3.8L Ford conversion (sold my last one to a customer in a hurry). I was getting ready to take it to the powder coater, who charges me $35 additional for the sand blast, and I decided to try this new equipment. With my old siphon unit this engine mount had taken two hours, no joke, to sand blast on previous occasions, so it is clear why $35 seemed reasonable. This new unit, after five minutes of setup time, did the job in less than 5 minutes. Hallelujah!! Home Depot in my area has what they call #30 blasting sand for less than $3.00 a bag. At that price I don't have to worry about recycling the sand too much. (Since the steel has no hazardous material on it, like paint chips, I could do the job in the garden) Now I am into things like etching glasses with relatives' names for Christmas gifts (another distraction). Anyway, I wish it hadn't taken so long for me to realize that there was something better than what I had. Thanks again. Bruce A. Frank +++ #8342 From: Budd Davisson Subject: Re: Budd, Thank You! Hooray, I finally did something good :-) bd PS I've found the #30 sand works better if you either screen it or keep a piece of 1/16" rod handy to unplug the nozzle from time to time. +++ #8444 From: Benton Holzwarth Subject: Compressors, again Compressors again -- I'm looking at models like these two -- They're of similar power, and both are near the 10 cfm@90psi guideline for hungry tools. Both are oil-lubed -- it'll be in an attached garage, the family needs to live with the noise, not that I expect 'em to mind the compressor next to the riveting. And both run on 220V. They're also both around $425. Where they differ: The first is 6 HP / 26 Gal and comes with wheels and weighs about 175 lbs. The second is 7 HP / 60 Gal, is set up as upright-stationary, and weighs about 290 lbs. My thinking is that the first really isn't 'portable' since no matter where it's parked it needs 220V, so I can't just power it up anywhere. But at 100 lbs less, it should be easier to move around the shop when necessary. Also, the smaller tank will mean more frequent cycling of the pump as tools run, but I'm expecting I may wind up working in relatively short shifts, and thought the smaller tank would be an advantage in getting up to pressure more quickly. (How fast does a compressor bleed down? I assume one doesn't normally release the pressure when knocking off for the night...) Am I missing anything else I should be considering here? I believe someone had said that the 60 gal upright was a good setup. There's a Harbor Freight in town, so I can pick one up w/o freight charges or hassles. Complicating the decision is that there is a refurbished rig on the Campbell-Hausfeld web site similar to the upright model for $385 (delivered in the 48 states). Benton 20dec01 +++ #8445 From: Jim Ash Subject: Re: Compressors, again I've got a 5 hp single-stage 60 gallon upright from Sam's Club that has served me well for 12 years. The brand name on it is Black Max, but I Imagine it's equivalent to the ones you're seeing. I pulled 20amp (220v) service with a switch for it and it sits permanently in the garage. Admittedly, there have been a few times when its permanent placement has been inconvenient, but in anticipation of this, I plumbed the whole system with quick disconnects and got a couple extra hoses which give me an operating radius of around 200 feet from my garage door. The problem with using extension hoses is that if the system is flowing much, you lose some pressure at the tool end. It hasn't been a problem for me because the tools I've used this way are either intermittent or don't suck much air. I've considered rigging my portable air can as a 'capacitive' tank (30 gallons - You'll want one at least a 10 gallon one for airplane tires someday anyhow) for the end of a long distance run, but haven't had the need yet. My father and brother each have 30-gallon 'portables', but I personally find dragging them around to be annoying. I ended up using one of those cheap 12v cigarette-lighter compressors to charge the pressure tank in my parents' water system after dragging dad's portable out and finding out his 25' hose wouldn't make it under the house to the tank. I'd rather play with my hoses. I shut off my electric feed, main tank valve and bleed the tank until I get no more water at the end of the session, so I leave lots of air in my tank. If I shut down with 100 psi in the tank, it takes maybe two or three months of non-use to leak down to 40 psi. Likewise from, an empty start, I guess it runs for 10 minutes or so to get fully charged, but then I let it cool and do an initial bleed right away after this event. Side notes - If you're going to paint, buff, or sandblast with this compressor, you'll want a side to the system with a filter and dryer, but no oil. An oiled side to the system is nice for the drills, wrenches, and rivet guns, but it sucks for buffing (The voice of experience, after coating my hood with oil spatter while attempting buffing). If you do any mechanic work, get an impact wrench. This has turned out to be the most invaluable tool for me over the years. Down side - It's made my driveway the place to be for family tire rotations and exhaust work. Jim Ash +++ #8446 From: "Del Rawlins" Subject: Re: Compressors, again > They're of similar power, and both are near the 10 cfm@90psi > guideline for hungry tools. Both are oil-lubed -- it'll be in > an attached garage, the family needs to live with the noise, > not that I expect 'em to mind the compressor next to the > riveting. And both run on 220V. They're also both around > $425. I've been trying to convince my wife that I'll really need the gargantuan Ingersoll Rand compressor (as opposed to a lesser unit) when I have a workshop again. The only argument that has had any real effect so is pointing out that a compressor with higher output and a larger tank will have to run less often, which means that she'll have to listen to it less often. > Where they differ: > > The first is 6 HP / 26 Gal and comes with wheels and weighs > about 175 lbs. The second is 7 HP / 60 Gal, is set up as > upright-stationary, and weighs about 290 lbs. I don't think I'd bother with a portable of that capacity unless I was planning on taking it to construction sites frequently where I needed to run some serious tools. I also wouldn't mess with a horizontally configured unit simply because they take up more floor space. In our tire shop in Cordova, we had a monstrous horizontal that took up a lot of space, BUT it was on the loft above the shop so it wasn't an issue. My dad also had a smaller horizontal unit in his garage, and we tried building a table over it in an attempt to reclaim some of that space, but the compressor vibrated the table so much that it was next to useless. For these reasons I am planning on a vertical unit to minimize the footprint. It will also be a lot easier to fasten to the shop floor than the big portable. Unless you are moving it around a lot, you'll want it bolted down so it doesn't move around on its own. I'm probably just going to get the biggest stationary compressor I can afford and pipe air wherever I could potentially need it. The shop in Cordova has air running in a steel pipe underground below the driveway over to the office/toy shop building. It's worked great for at least 15-20 years with the exception of one winter a few years ago when it froze up for a while. Eventually I might get a little portable compressor but for the typical job of airing up a flat tire out of reach of your hoses, its usually less hassle to just fill a portable tank to use. Old air brake tanks (off of trucks) are readily available and can be adapted to this purpose. Mounting a couple to the wall near your compressor might be an expedient way of adding tank capacity if needed. > advantage in getting up to pressure more quickly. (How fast > does a compressor bleed down? I assume one doesn't normally > release the pressure when knocking off for the night...) So long as all of your pipes, hoses, and fittings don't leak, it shouldn't bleed down much if at all. I would often not drain the system if I was planning on returning to the shop after dinner to work on whatever, and would only turn the compressor off. If the compressor immediately started running when I turned it back on later, I knew that something somewhere was leaking. The big fear was a hose or regulator failing, which is why the compressor was always turned off when the shop was locked up, regardless of whether the tank was drained or not. If it were left on and something let go, it would run flat out without a load until somebody showed up and noticed it, which might not be for a while. Not good! Last summer this actually happened (fortunately during business hours) when an old water/oil separator burst in the half of the office/shop building that is rented out to a sporting goods store. It was an autobody shop years ago and none of the air piping stuff was ever removed (or the numerous 220V outlets!). Scared the hell out of my tenant when something in his storage room started hissing like mad! I finally found where the shutoff valve for the underground pipe was and replaced the separator with a piece of pipe and a shutoff valve. My next workshop will have a shutoff valve at the beginning of every pipe in the air system. My stepmom couldn't use the blast cabinet for her glass etching for several days until I had time to fix it so we could restore air to the building. Anyway bottom line is I really like compressed air and I don't think you can ever have too much of it in your shop (excluding a failure of the compressor's pressure switch). If you are only planning on buying your compressor once, get the next size larger than you think you need and you probably won't be unhappy with it later on, especially if you choose to do your own sandblasting at some point. Del Rawlins +++ #8447 From: "Del Rawlins" Subject: Re: Compressors, again > If you do any mechanic work, get an impact wrench. This has > turned out to be the most invaluable tool for me over the > years. Down side - It's made my driveway the place to be for > family tire rotations and exhaust work. Excellent post! If anybody is thinking about getting an air impact wrench, the Ingersoll Rand is the best made. Working in the family tire shop we used a lot of different wrenches over the years, and I don't think I'd ever buy anything but IR impact tools now. Be sure to get a set of impact sockets to go with it; don't use your regular sockets and extensions since they won't last long under impact use. A set of impact wobbly sockets will make getting into inaccessable places a lot easier. As for exhaust work, I usually start out trying to use an impact wrench and wind up finishing with the air cutoff tool. I don't think the people who install them at the factory ever heard of anti-sieze lubricant. If you do your own oil changes an air grease gun is a real luxury and not terribly expensive. Del Rawlins +++ #8448 From: Brian Cox Subject: RE: Compressors, again > Eventually I might get a little portable compressor but for > the typical job of airing up a flat tire out of reach of your > hoses, its usually less hassle to just fill a portable tank to > use. Old air brake tanks (off of trucks) are readily > available and can be adapted to this purpose. Mounting a > couple to the wall near your compressor might be an expedient > way of adding tank capacity if needed. My two cents worth, My 73 cu ft oxygen tank went out of date a couple of years ago. They are life limited to 24 years. I think this equates to one filling a day, or about ~9000 cycles. This rule was mandated by the FAA based on airliner oxygen systems, which are filled more frequently than ones in GA aircraft. I only had to fill my bottle once every two years or so, making the 24 year limit kind of arbitrary. A new bottle cost nearly $1000. The shop that replaced it just XXXX'ed out the date code so it is not airworthy. He told me a lot of people save these and mount 1" threaded pipe fittings at Home Depot and turn it into a portable tank. They work great - oxygen is pressurized to 1800 psi, so they can handle anything a shop compressor can put in them. The guy who filled the bottle said I could have other ones from him for free, as he just had to dispose of them. You might check your local Oxy bottle filler to see if they would have any. Brian Cox, #478 +++ #8479 From: Benton Holzwarth Subject: re: Compressors, again Following up on my initial query, another compressor datapoint -- I called to talk to the Campbell-Hausfeld people about one of their refurbished compressors. The C-H ones were gone, but they have three of the 'Husky' brand. They make Husky as well, for Home Depot. The guy explained that the Huskys are identical to the comparable C-H model, except "they have a better air filter." By my reconing, the 6.5 HP / 60 Gal Husky runs $400 new, vs. $430 for the C-H at Harbor Freight. And I've got a Home Despot less than a mile from home, whereas Harbor Freight is clear cross town... Benton 26dec01 +++ #8852 From: Russ and Penny Erb Subject: Today's machining lesson--taps and dies I have designed a different trim actuation system that greatly increases the mechanical advantage between the trim wheel and the trim tab. That is, instead of requiring half a turn of the trim wheel to move the trim tab through its full range of motion, it requires multiple turns like you would find in most Cessnas. I'll post pictures and drawings later, but today's lesson is on taps and dies. This new system has several places that require cutting threads, including the main jackscrew thread that makes it work. A while back I picked up what appeared to be a nice tap and die set from Harbor Freight (that should tell you something right there...). It didn't cost much, and it appeared to have everything I would need. Jumping forward in time--it wouldn't cut new threads worth a flip. Closer inspection eventually revealed the problem. Taps and dies meant for cutting new threads (such as the ones I eventually bought) have quite a few partial depth threads before reaching the full depth threads. For instance, on a good plug tap, about the first 5 threads are only partial depth. This allows the tap to slowly work its way down to the full depth of thread by taking small pieces off with each cut. The taps in the Harbor Freight set only had 2 to 3 partial depth threads. Because they had to cut quicker into the metal, trying to use these taps quickly got to a point where the tap could no longer be turned, no matter how much cutting oil you slathered on it. The dies were similar, having almost no partial depth threads. In the end, this is the conclusion I came to--the taps and dies in the Harbor Freight set were intended only for cleaning up already existing threads (re-threading), not for cutting new threads. This conclusion was supported by McMaster-Carr, which sells taps and dies specifically listed at "rethreading", separate from the taps and dies for cutting new threads. Therefore, if you come across a "good deal" in taps and dies, be sure to look at the partial threads to determine which kind you are getting. Using rethreading taps to cut new threads will lead to aggravation at the least and a broken tap in the hole at the worst (you can't drill them out--taps are harder than the drill bits). Russ Erb +++ #9021 From: bearhwk272@a... Subject: Topic is Sand Blasting Ok, enough of this old parts stuff. I am working on a sandblast or glass bead setup where I have a box with blasting nozzles that will blast the fuselage tubes in their full length prior to cutting and fitting. Just debarked 4130 tubing clean and ready to use. New tube in one end, clean new tube out the other,should save a passel of time in fuselage blasting. Now If a guy was to prime the steel prior to working with it, fit it up and clean the weld area, then final fuselage work would consist of blasting the joints followed by local priming, then topcoat. How is that for a concept? Kevin +++ #9025 From: Russ and Penny Erb Subject: RE: Topic is Sand Blasting You might get away with it in Phoenix, but I wouldn't try it where humidity is the rule. As for priming before welding, I had to cut apart a part that had already been primed to fix a misalignment. Upon welding, the primer burned back pretty far, and I don't know what it did to the primer that got hot but not hard enough to burn. With the incredible number of places that need welded on the fuselage (don't forget the stringer standoffs and about a billion tabs for the floor/cowl/windshield/etc) I think you would end up with about 30 to 40 % of the tubes (at the most) that still had primer on it. I don't think you'll see any real time savings by pre-priming. Any time savings would probably eaten up in time spent cleaning primer off prior to welding. Russ "Doesn't that guy ever like an idea?" Erb +++ #9027 From: Budd Davisson Subject: Re: Topic is Sand Blasting Good idea, but in reality, it's not necessary to actually blast a satin surface on the straight parts of the tubes. A little Scottbrite will do it just fine. The blasting is mostly needed at the clusters. I really like the concept though. A possible problem in areas that actually have humidity, which you and I don't, is blasted tubing rusts like crazy. bd +++ #9032 From: "Bruce A. Frank" Subject: Re: Topic is Sand Blasting > I am working on a sandblast or glass bead setup where I have a > box with blasting nozzles that will blast the fuselage tubes > in their full length prior to cutting... Don't do it. It will be one big rust bucket before you finish. Leave the mill scale in place, in fact add a little WD40 to hold everything somewhat more rust free. Blast only the areas you are going to weld, weld them, then once cool hit them with a light coat of WD40. Water Displacing 40 is easy to remove when you get ready to paint, the sand blast process eliminates it...no residue to mess up the paint. Even if you have to weld in an area contaminated by WD40 it is light enough to burn off leaving virtually no carbon residue to contaminate the weld. If you are a stickler then wipe with a little acetone before welding. Priming the steel will cause a much greater problem when welding than even the heaviest layer of mill scale (or WD40). One last point, if you follow your suggestion, blasting the joints for a final prime after welding will not do the job. It is virtually impossible to blast the clusters and joints without damaging the primer on other parts of the fuselage and getting little bits of sand or bead imbeded in the primer on distant sections of tube. Been there, done that. Learned the hard way. Bruce A. Frank +++ #9034 From: Benton Holzwarth Subject: Router cut question I tried using a router to lop off some Al blanks for the parts I was working on. I used a new "2 flute straight, 1/8" cut diamter" cutter. It seemed to leave a feather of Al chaff on one side of the cut or the other, according to which direction the router was moving. Is there something I need to change -- do I need to feed faster or slower, or is it just part of the way it works? The edge cleaned up fairly easily, but I was expecting a cleaner cut. Benton 20feb02 +++ #9035 From: Del Rawlins Subject: Re: Router cut question > I tried using a router to lop off some Al blanks for the parts > I was working on. Well, I'm one of the guys who cut out all of his ribs with tin snips, but I did try the router method briefly (didn't like the mess of aluminum chips everywhere) and I didn't have that problem. I used a 3/8" trim bit that left the edge as clean as if it had been cut with snips. I think you are using too small of a bit that doesn't cut fast enough, so it heats up and sort of melts its way through. Del Rawlins +++ #9036 From: "Bruce A. Frank" Subject: Re: Router cut question You need a larger diameter cutter, 1/2" or so. You also may find some lubrication will help. I find the wax-like saw blade lubricant available through wood shop supply stores works as well as anything. Kerosene works but you'd need to squirt it continuously while routing for best results. With those changes you should get a perfectly smooth edge with very little "feather". When the feather starts to show up lubricate the edge and cutter with the waxy stuff and or move a little faster. If you move too slowly the aluminum "dust" that is thrown off coats the cutter and may melt slightly a to refuse to the edge you have just routed. Moving quickly along the edge you are cutting allows the edge to stay clean. Bruce A. Frank +++ #9042 From: Budd Davisson Subject: Re: Router cut question Re: Routers We did quite a bit of experimentation with different size router motors and different bits at the plant and found we could even use a little trim router with a 3/8", two flute. It has little or no dust and you can avoid build-up on the flutes by slowing the feed rate just a little. Some wax or something helps keep it form sticking. This is a fool-proof way of cutting, clean and some cheap aluminum angle (2 x 2 x 1/4) makees a great straight edge. bd >>> 4sep02 #9154-11297 +++ #9155 From: Tim Subject: Re: Re: New file uploaded to Bearhawk This was at an RV builders site....I also noted the reference to Murphy A/C...Sharpie pen both fine point and ultra fine (very thin line) are what work well... Lacquer thinner removes the permanent ink +++ #9159 From: Russ and Penny Erb Subject: RE: Marking Pens Lumocolor by Staedtler. I used the fine tip version. A quick web search turned up http://www.staedtler-usa.com/category1/markers/lumocolor.htm Don't try to use them on anything too hot to touch or you'll melt the end and then it won't work at all. +++ #9462 From: Benton Holzwarth Subject: Blue Ink? Way back in highschool machine-shop, twenty-five years ago (I went to a 'vocational' HS) we used some stuff that I can only remember as 'blue ball point pen ink in a bottle'. We'd paint it onto a piece of metal, then, when dry, scratch the cut and drill pattern onto the surface. Does anyone still use this stuff? Does anyone still sell it? I'm contemplating cutting out one of Bob's bucking bars (BT '95-combined Pg 8), and that seems like the way to prceed, but I've never bought any of this stuff. What's it called? Will they laugh at me if I call it 'ball point pen ink in a bottle'? +++ #9463 From: "Dan Montee" Subject: Re: Blue Ink? It's called layout fluid, steel blue, sold by machine tool stores yet today. I have a bottle manufactured by DYKEM, ITW Fluid Products Group, St Louis MO. 800-443-9536. Yep, I still use the stuff. +++ #9468 From: "greg" egregvana@... Subject: Re: Blue Ink? i think what you are looking for is prussian blue. you can get it at a good auto parts with a machine shop. it is used wet or dry for setting gear backlash etc. permatex is th brand i use +++ #9469 From: "Tex and Pat Goerger" Subject: Re: Blue Ink? I believe you are looking for Dykem Layout Fluid. You can get it in paint brush cans or aerosol cans, Aerosol cans sell for about $7.00 at any shop that sells machinist parts or tools. I use it for layout work when doing the tool and die work for plane parts. You can check in the Enco catalog on line for it. +++ #9470 From: "Shannon" shanspur@w... Subject: Re: Blue Ink? Hi guys This is my first post, so I'll warn you up front that I sometimes spout off with insufficient knowledge, but this time I'm pretty sure. Blue layout dye, usually just called "Dykem" because so many people use that brand, is different from Prussian Blue which is really artists oil paint. Dykem, either spray or brush on, dries in a couple of minutes for scribing. Prussian Blue takes days, even weeks to dry. It's used in checking gear lash because you can brush it on one surface and it will transfer to another surface if they make contact. We use both these products in jig shop at Cessna where I clock in and get paid. (No one claims we work.) Hope this avoids confusion instead of making it worse. +++ #9471 From: Bob Romanko Subject: RE: Blue Ink? For what it's worth, Prussian Blue is also used in lapping valves. Put some on the valve face when you think you're done with lapping, then put it into the cylinder. Pull the valve stem firmly, then gently lift the valve off of the seat. You should see a nice blue line of consistent thickness on the center of the seat. SHOULD being the key word in the last sentence (grin)! +++ #9472 From: "Lee H. Erb" Subject: RE: Blue Ink? > "Dykem" because so many people use that brand, is different from > Prussian Blue I am glad some one else could spell "Dykem." The prototype F-22 has some landing gear parts "colored" with Dykem to distinguish them for some reason. I called it out on a drawing but forgot what and why. Senior Confusion (SC) I guess. Can't remember what I did 4 years ago but I can 50 - 60 years ago. When I was about 12 I made some toys for a cousin and wanted a pretty blue paint. Unfortunately I asked for "Prussain Blue". The "paint" never did dry! Finally an uncle (tool and die maker) educated me. One does learn from mistakes if he survives. +++ #9476 From: "Corky Scott" charles.k.scott@d... Subject: Re: Digest Number 740 My understanding with the use of Prussian blue is that it is used to discern the depth at which the engaged gears are meshing, not for backlash. Backlash is determined using a dial gauge; you set the gauge with the pointer against one of the gears and then move it back and forth to see how much movement there is between the front side of the tooth versus the back side of the other opposing tooth. So basically you clack the gear back and forth measuring the movement (backlash). That's one adjustment, the other one is the depth at which the teeth engage each other and that is adjusted by using prussian blue to see where the tooth to tooth contact is actually occurring; this is a visual observation, not an instrument observation. At least that's what I was taught in auto mechanics school, the differential class. +++ #9478 From: "Daniel Fox" Subject: RE: Blue Ink? This use (and others mentioned here) for Prussian Blue seem to point up it's utility as a "transfer marking fluid" for lack of a better term. I have used it in the repair and restoration of ancient machine tools. If you spread in on a reference-flat surface and rub that on a should-be-flat surface you can mark the high spots. Hand scrape and repeat ad infinitum, you get blind, crosseyed, crazy, and a _very_ flat bearing surface. It has also been my experience that it basically never dries. Welcome, Shannon. I'm sure that you will bring lots of good information to the discussion. +++ #9514 From: Budd Davisson Subject: Re:Cheap dykem I've always used Magic markers for layout. Just scribble on a layer of what ever color contrasts best with the material and scribe your lines. For aluminum stuff I won't be scribing, I fog on a coat of lacquer-based, sandable (it has more tooth to the surface and takes pencil better) gray automotive primer from a spray can, then use a .05 drafting pencil for the lines. When I'm done, it wipes off with lacquer thinner. +++ #9850 From: "jim" dewcraft1@... Subject: Cutting Long Alum Sheets Has anyone come up with a good way to cut long (12' plus) sheets of 6061 with a nice, clean, sheared look? My only, maybe, decent idea so far is to use an air powered cut off abrasive disk. Hand snips would never work. Any better ideas? +++ #9851 From: Budd Davisson Subject: Re: Cutting Long Alum Sheets router with a long extruded aluminum angle as a guide. +++ #9852 From: shell "Shelly" Subject: Re: Cutting Long Alum Sheets Jim, I am presently looking at pneumatic shears. They seem to sell for $80 to $100 and they are imported, of course. Here is an example - http://www.bosstool.com/pisgripairme.html My concerns are - -does it really leave a smooth cut edge? -can you follow a straight edge guide? -will it mark the surface? (can always use tape of some sort) -will it cut a curve? some say radius as small as 5" -are the three jaws sharpenable? -are the three jaws replaceable? -is the speed variable? (I don't know if this is important) There also are electric shears, which are made by the big companies, like B & D, Milwaukee, etc, but they are twice the price. I'm sure someone on this group has used one of these tools! +++ #9853 From: "Chris Vuxton" Subject: Cutting sheet metal No, no, no to the disk idea. I take it you are not talking about ribs here. You can use a router or air nibbler like this one from http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=46061 and a straight edge. My nibbler goes through like a hot knife. The only thing is that there are little, and I mean little, half moons of metal left over. I set up a 55 gallon drum with a carpeted cutting table on top and a hole in it to catch the bits. Plan your cuts and go the shear route. Check local high or trade school. The cost would be well worth it in the end if they charge you. If not, make a donation and you'll be surprised how willing they'll be to help you again. +++ #9854 From: "Bruce A. Frank" Subject: Re: Cutting Long Alum Sheets Electric shears can do the job when cutting in the range of thickness for which they are designed, but it if one is careless about keeping the feed pressure on while cutting they can roll the edge slightly. I have a very good quality set, but if a long cut has to be distortion free then I follow Budd's advise and use my router with a stout guide and a little cutting lubricant. Just like a sheared edge you'll probably have to deburr the cut edge. Masking tape on the aluminum surface adjacent to the cut will help prevent scratches and also help the router to slide smoothly. +++ #9857 From: Ken Beanlands Subject: Re: Cutting Long Alum Sheets I have used a Pneumatic Shear for some time now and find it a good compromise to buying a shear. It forms a 1/4" spring-like coil as it shears and cuts quite quickly. I'll try and answer your questions below: > Jim, I am presently looking at pneumatic shears. They seem > to sell for $80 to $100 and they are imported, of course. > Here is an example - > http://www.bosstool.com/pisgripairme.html > > My concerns are - > > -does it really leave a smooth cut edge? Yes, as smooth as a foot shear. It should still be filed. > -can you follow a straight edge guide? Depends on the shear, but I've had some success in this. The shear sometimes pulls away from teh strait edge leaving a smallbump that needs to be trimmed after. > -will it mark the surface? (can always use tape of some sort) Not that I've noticed, but I've always made my cuts with the protective plastic coating left on the aluminum. > -will it cut a curve? some say radius as small as 5" Not really well. You may get away with a 5" radius but definitely nothing less. A nibbler may work better for this. > -are the three jaws sharpenable? I haven't had a need to so far. > -are the three jaws replaceable? Depends on the manufacturer. > -is the speed variable? (I don't know if this is important) It's not really important as the speed of the shear is basically dependant on how fast you feed the shear across the sheet. There is definitely a "sweat spott" in feed speed and cutter speed, but you have to play with it a bit to figure that one out. +++ #9857 From: "Kent White" Subject: RE: Cutting Long Alum Sheets > -are the three jaws sharpenable? I have had no success sharpening them, although a good scissors man could perhaps do it. The problem is that the clearance is lost as the edges are sharpened, and then you need .001" shim stock to close up the clearance. They Will get dull, especially on stainless, and faster if import quality. > -are the three jaws replaceable? I usually buy a new complete head, although I have gotten the blades and the screw/bearing/washer driver assy as a kit from Milwaukee. I believe the shear heads are made by only one Mfr, at least in the US. Kett and Milwaukee are the leaders, although I have used import air shears which use "similar" heads. They do not cut as well as the Milwaukee/Kett, and go dull sooner. Best to lightly oil the cutting path prior, even with nibblers and routers. WD40, CRC, Boshield, are fine. > -is the speed variable? (I don't know if this is important) I use the heads on VS 3/8 electric drill motors, after removing the chuck. The air models can be feathered if your fingers are good. Keep pressure at 90psi. Gently engage the unit into the metal and lift or twist to find the "sweet spot" where the shear takes off on its own. Sometimes there is distortion or a serrated edge, even on hard aluminums. Nibblers and routers are less prone to distort, but serration can occur. Feed or cutting rate should be reduced if serrations occur. Use oil or beeswax on the path, as I mentioned. Nibblers will fill your sneakers with moons, which may bite. I wear long pants with cuffs over sneakers to shed the sharp little "shirikin stars" away from my socks/tender feet. +++ #9864 From: Russ and Penny Erb Subject: RE: Cutting Long Alum Sheets I have a set of pneumatic shears of the Harbor Freight variety. Strangely enough, they've held up well, but I've only used them on .032 2024-T3 or thinner. I use them primarily for rough cutting, such as cutting out rib blanks that will be routed to the final shape. I have found that they can be used in the same fashion as snips. To wit: First cut about 1/8" away from the final line. You'll need to be closer than the cutting strip is wide. Then trim to the line, using just one side of the jaws. You can control the direction of the cut much better if only cutting on one side. With practice you can make reasonably accurate cuts. If you're not happy with your results, remember to cut a little farther out and exercise that file. There is definitely a technique to this tool--with the right cutting angle and pressure, it will happily eat its way right through your sheet. Get the angle or pressure off just a bit, and it can stop dead in its tracks. This is because it only cuts over a distance of maybe 1/8" at a time, so you've got to get that part of the shear on the metal. If you're having trouble, pull the trigger and move it up and down until it starts cutting. Soon you'll pick it up and use it without even thinking about it. +++ #9875 From: John Thompson Subject: Re: cutting long sheets Heres a tip I saw in the Zenith newsletter: use a straight edge and a knife used for cutting acrylic/lexan sheets. Use the knife for several passes on the sheet with the straight edge. If I remember right the guy was using it on sheets up to .032, and said it would probably work on thicker sheets too. This knife has a hook in it, much like a carpet or vinyl cutting knive. I dunno how long it would last on al. though. +++ #9877 From: "Corky Scott" charles.k.scott@d... Subject: Re: Digest Number 776 > Has anyone come up with a good way to cut long (12' plus) sheets of > 6061... Don't know about the sheared look, but I found that I could lay out sheets of aluminum and craze them with a sharp carpenter's knife and then bend them to break. +++ #9880 From: "Shannon" shanspur@w... Subject: RE: WD-40 I don't know if any of you have had, or will have, problems with this, but paint shop at Cessna begs us to keep WD-40 away from any part that will be painted. They say it's nearly impossible to clean off, and positively prevents adhesion of the paint, and many times causes fish eye. It's the silicone. May be just the type of paint they use that causes the problem, but straight motor oil is apparently easier to clean up. Trouble is easier avoided than fixed. +++ #9881 From: "WAYNE ESTMENT" Subject: Re: Cutting Long Alum Sheets I used a pneumatic nibbler uses about 5 mm up on the cut but does the job very quick +++ #9902 From: "jim" dewcraft1@... Subject: Cutting Long Alum Sheet-Answer In answer to my request for info on cutting long aluminum sheets, and getting a really neat, "shear like", clean, straight edge, I got a lot of suggestions, some "off group". I tried them all, every one - powered shears, nibblers, etc. I really appreciate the input, and with more practice some methods I decided against may have produced superior results. But... the final method was the router. I used a standard DeWalt with router guide ($25.00 extra), and a 5/8" D. carbide bit from MSC. It took longer to assemble the guide than to cut the first scrap piece. The results couldn't be neater or straighter. Thanks to all who made suggestions. +++ #9903 From: Budd Davisson Subject: Re: Cutting Long Alum Sheet-Answer Gee, I think I heard someone say that earlier. We use a formica trim cutter. +++ #9904 From: sonny cilley Subject: Re: Digest Number 780 Hi guys, back to the long straight aluminum cuts, I too use a router with a straight edge,but instead of a big router bit or trim bit, try a down spiral milling bit,it throws the chips all over your feet but it produces a good cut,. just make sure all chips are gone before starting additional cuts, they scratch the sheet goods pretty easily.the milling bits are small in diameter so it saves aluminum. +++ #10402 From: "Bruce A. Frank" Subject: Re: Plasma Cutter > Having satisfied my desire for an inexpensive plasma cutter, I'm now > attempting to determine it's usefulness The intense but brief heat generated on the edge of the kerf does have some effect on the temper of the alloy in theory , but, with aluminum, I have never seen any changes that impacted the mechanical strength of parts cut that way. On mild steel nothing goes on that causes any problem what so ever. With alloys such as 4130 there is a very slight chance that some quench hardening can take place adjacent to the kerf. Because of that chance usually the cut edges are sanded ever so slightly or bead blasted. The heat affected zone on plasma cuts is restricted virtually in the kerf. The hardened layer is literally just a few tenths of a thousandth thick, less than the a mill scale layer, that is easily removed with sanding or blasting. This brittle layer, though extremely thin, can propagate cracks into the rest of the metal, but the chance is slim. But, I am envious. I have always wanted a plasma cutter myself. +++ #10410 From: "Kent White" Subject: RE: Plasma Cutter... cracks According to the specialists with the Aluminum Association, plasma is not recommended for cutting aluminum, at least not without understanding the danger. The plasma cut embrittles the edge of the aluminum (all alloys) to the extent that microcracks penetrate back into the sheet about 3X metal thicknesses. Test for yourself: make the plasma cut and then re-shear the edge at 2X metal thicknesses back. You will get a shower of bits for your efforts. +++ #10530 From: Tim Subject: This Weeks' Builder Tip 'Filtered Box Fan' http://www.woodworkingtips.com/etips/etip020705ws.html Anyone painting their Bearhawk, a nice addition to your' face mask ;-) +++ #10550 From: "Bruce A. Frank" Subject: Re: Where do I put my plans? > Today's workshop tip: Where to put your plans while you're working. I mounted a large green chalk board in the shop. The backing of chalk boards these days is thin sheet steel, I stick my plans to that with magnets and have room to chalk notes of importance. A chalk board in the shop really comes in handy just to keep track of building notes and adjustments. +++ #10556 From: Ken Beanlands Subject: Re: Where do I put my plans? When I started the Christavia, I had access to a large format scanner (60" wide by unlimited length) so I scanned the lot and plotted them off at 1/2 scale. They are a lot smaller thatn the originals and I don't care if they get damaged or dirty. Obviously, 1/2 scale is not as practical with the BH plans, but they could still be copied to form a set of shop drawings. +++ #10560 From: Tim Subject: Re: Where do I put my plans? 2.5' x 3' Rectangle of 1/4" mdf.......Two hinges at top some trim around the border with a small ledge at bottom with a nice wooden toothbrush/cup holder for 'Sharpie's/pencils' and 2 -3 clips screwed into the mdf to hold the plans.........Swings up perpendicular to wall, adjacent to main work table.....Secured to floor joists (unfinished basement). +++ #10566 From: supermexgarza@... Subject: Re: Where do I put my plans? i built a 24x26 cart it is 6 ft tall and has "A" shape looking at it from the side, on the front i binded the plans on a gadget simular to a coutain rod (316 satinless not required) "but in my case it was laying aorund", i can flip the plans one behind the other, and on the back side of the cart it is a 4ft x24 in. peg board with hooks for the most needed tools small stuff, snips, tape, hammer sqare and such, it works well for the simple fact that it does not have a flat surface to sit the coke, coffe, or beer depending the time of day i want to put a sheet of clear plastic so i can put my dirty fingers with out touching the plans. +++ #10633 From: Benton Holzwarth Subject: RE: This Weeks' Builder Tip 'Filtered Box Fan' There was a similar unit described in EAA-SA a couple months back (read it this week, suggesting it was somewhere around the April issue -- will followup when I have a specific reference.) The idea there was a box within a box. The inner box was formed on several sides with filters, and the outer box, about 3' on each edge and built strong enough for use as a work surface for sawing, etc. Or just park it near where you're working with some other tool. Sawdust is drawn in through slats and collects on the inner box. The builder there called out a specific Grainger motor/fan to use to pump the air out a side duct. I have a large squirrel-cage fan, rescued from a furnace being replaced, that I thought I might use for one of these. I understand squirrel cage's tend to cavitate more easily than other types, so it may not work as well as a regular fan, but the price was right for an experiment. +++ #10722 From: Drew Schumann Subject: Fluting pliers (was: Repairing the wing rib form) So would it be okay to explain how to make a quick and easy fluting tool that is non scratching? Follow the instructions that come in one of the early newsletters, except, once you've drilled the 1/4" hole down the jaw faces, put black electrical tape tightly on one side, and clamp down hard on some epoxy steel type epoxy putty. Leave it that way, at least overnight. The epoxy will cure and the electrical tape would add the clearance you need. Then, take some additional putty and swipe it along the female side of the jaws until it just fills in the serrations in that side of the jaw. If you do a neat job, it should dry smooth and need "zero" finishing. Use good steel putty or it will deform under pressure and not flute enough. >>> 20may03 #11298-18250 +++ #11316 From: bearhwk272@a... Subject: COOL Building Tip! Actually 2 Cool Tips Well, not as much progress as I would like to report but here are two tips that every one can use. Some can use it in the summer, others can reverse it for the winter. Tip # 1. When working in the exreme summer desert heat in the 110 deg f mancave, wrap a kitchen dish towel around your neck that has been dipped in ice water. provides quite a bit of relief. Tip # 2. Put on a pair of long sleeve cotton jumpsuit coveralls. Then connect a piece of 4 in dia flexible ducting, like for the dryer vent, to the cutout in the coveralls that allows you to access your inside pocket. Connect the other end of the ducting to a takeoff that you have handily added to the house airconditioning ducting. Turn the house control to "on" and have at it. ( Hint ) Always ensure that the house discharge pressure is greater than the suit discharge pressure .... if you get my drift) Kevin Deutscher +++ #11480 From: "Bruce A. Frank" Subject: Swagging tool I just passed this along to some of the V-6 STOL builders and thought the Bearhawk group might find this useful info. Look what I just ran across at Home Depot. This bolt cutter style tool (not a modified bolt cutter but a real swagging tool) was on sale for $20. On the right in the picture is the bolt together unit I bought years ago from Aircraft Spruce. I have just finished doing about a dozen swages, half with the AS tool and half with the Home Depot tool. All the swages miked within a couple of thousands of each other. There was variance from both tools. One crimp would be larger and the next crimp smaller than the other. Size of the crimped area varied slightly from one crimp to the next with the same tool. That variance overlapped from one tool to the other. The paper label visible is from the Home Depot tool. I do not remember what I paid for the AS tool, but my thought is that it was about the same as the Home Depot tool. Bruce A. Frank +++ #12481 From: Benton Holzwarth Subject: Cutting cable? Whoever pointed out the tip about Home Despot carrying cable swaging tools, thanks! I never expected to justify buying one of the fancy lever ones. In my latest 'Spruce order, I added: 1 GA-1P Go No-Go Sleve Gauge 24 1/8" copper sleeves 4 Cable Thimbles 12' 1/8" 7x19 Galv Control Cable A whopping total of $17 to try out the tool. An observation is that like any new tool, the second part is significantly better than the first. The second looked as good as the ones done by the A&P. Second observation is that, while I haven't proof-tested the eyes, at least according to the gauge, the Home Despot swager did a perfectly good job. So, more questions -- What's the best way to cut the cable? AC43.13 only says not to apply heat, at least so far as I could find. /AC43/3A-CH7_8.PDF talks about control cables, and is on the Bearhawk CD, thanks Russ. Masticating my way through the cable with lineman's pliers, I figured there must be a better way, short of buying a cable cutter (and doubling my current investment.) Is a cold chisel and anvil likely to be more effective? How about drilling an 1/8" hole in some sq stock, than spliting it lengthwise, as a clamping block. With cable clamped in vise, cut with a hacksaw close to the block? How about splitting open a compressed sleeve? Seems like that might be best accomplished with a cold chisel. Any other suggestions? I bought 1/8" 7x19 cable. Would this be less or more preferred compared to 7x7? I'm guessing both are the same strength, but the 7x7 is a little stiffer. Benton +++ #12482 From: "Collin Campbell" Subject: cutting cable What's the best way to cut the cable? The best way perhaps is by using a special cable cutter with the rounded or triangular jaws that don't crush or deform the cable. But since I don't own one, I wrap the cable with masking tape and use a die grinder with a thin 1/16" cutoff disk and cut right through the center of the making tape. The tape keeps both ends from unraveling. It works real nice, but some day I may just go buy one of those fancy cable cutters. Collin Campbell #370 +++ #12483 From: Russ and Penny Erb Subject: RE: Cutting cable? Is $20 too expensive for you? I have the S&F No 316 Cable Cutter (Aircraft Spruce, P/N 12-18600, $19.75, page 501 2002-2003 catalog) and it works great. Cuts through 1/8" stainless cable like its not even there. I was surprised by how well it worked. Recommended without reservation. Russ Erb +++ #12484 From: "Bruce A. Frank" Subject: Re: Cutting cable? I also never thought I'd have a "fancy" set of cable swaggers. Sure makes a lot of stuff I had put off very easy to do now. As for cutting the cable, I use another tool bought at Home Depot which is, I think, designed for fence work. The slots cut 1/8" my stainless with never a stray wire. After some experimentation I have found that a wrap of masking tape and then cut through the center of it creates a perfect shear with no un-raveling (though there has been really no problem with even bare cable) Bruce A. Frank +++ #12486 From: Tony Dean Subject: Re: Cutting cable? Swagger or Nicopress? I was of the impression that a gage operation required rather pricy equipment to swage the fitting directly to the cable. Or are these terms being used interchangably these days? I know that from AC 43.13 7148 the two types are handeled separately. I guess what I want to know is if the swaging equipment is not a lot smaller and more affordable? I like the clean elegance of the swaged terminals but the cost of the Nicopress process is probably going to be the deciding factor. Regards Tony Dean +++ #12487 From: "Bruce A. Frank" Subject: Swagger or Nicopress? Here is the picture I sent out before. The Home Depot tool on the left which cost me $20 on sale and the inexpensive tool available from Aircraft Spruce on the right which is, to say the least, slow, and originally cost me about $20 including shipping. Both of these tools create the same type of compression of the fitting and as far as I was aware is acceptable in all aviation cable applications. The other process, of which I am aware, is a hydraulic tool that compresses the whole fitting, no bands of compression, onto the cable (a VERY expensive tool). And yes, I am using the terms interchangeably which probably is incorrect. While I am here again I am going to try to remember that the word I intended to use is properly spelled "swaging" or "swager" whereas I, and my spell checker, keep wanting to spell it "swagging." I guess one can "swagger"( to conduct oneself in an arrogant or superciliously pompous manner; esp : to walk with an air of overbearing self-confidence : boast, brag) after doing a perfect job with the "swager."( a tool used by metalworkers for shaping their work by holding it on the work or the work on it and striking with a hammer or sledge: To compress a fitting to grip a rod or cable ? 1996 Zane Publishing, Inc. and Merriam-Webster, Incorporated Bruce A. Frank +++ #12489 From: Tony Dean Subject: Re: Swagger or Nicopress? That clears it up nicely. I was kind of hoping you had run across an inexpensive "swager" but it loosk like the Nicopress process as defined in AC 43.13. Nicopress was developed by the telecom industry since they used so many cables and was much less expensive and used tools that could be taken out to the field. Swaging actually compresses the part directly to the cable and is stronger but more expensive. I was kind of hoping that the costs had come down but looks like the marketing depts are loose again (they never seem to care too much about using the correct terms). Oh, well maybe by the time I get ready to make my cables there will be a low cost swaging tool. Of course the ends are still very pricy but we don't need too many. td +++ #12490 From: "Bruce A. Frank" Subject: Re: Cutting cable? The 7x19 is the correct choice. The 7x7 is too stiff to wrap around pulleys very well and will work harden more quickly. My book actually shows that 7x19 (1/8" galvanized steel 2000 lbs)is stronger than 7x7(1/8" galvanized 1,700 lbs breaking strength). The difference between the two with stainless is less and depending on the alloy selected 302, 304, 305 or 316 can range from 1300 to 1700 lbs. Note that the 304 and 302 meet mil spec whereas 305 and 316 do not. 302 is more fatigue resistant than 304. Both 305 and 316 have a lower breaking strength at about 1300 lbs, but can you imagine pulling hard enough on the stick to exert 1300 lbs? In application all four of these alloys of stainless work well and last virtually forever in even the harshest salt water environments. (oh, one last point, galvanized steel has the highest resistance to fatigue--fatigue is not caused by the light tensile loading in aircraft control surface application, but from the bending stress or wrapping around a pulley) Bruce A. Frank +++ #12491 From: Benton Holzwarth Subject: proof-testing cables Thanks for the ideas on cutting cable. The guy at Home Depot handed 'em to me, and was ready to write me a price-wavier slip, so I didn't spend a lot more time looking around then. (He couldn't find that they were on sale in this area, but extended me the $20 price on the spot. Heck, I wasn't going to complain at $26.) > ...but can you imagine pulling hard enough on the stick to exert > 1300 lbs? What's the leverage built into the stick? If we've got 10:1, yes, I could. (Hmmm, quick look at the plans, looks like the first lever is 10.5:1.5, but we loose about half that through the following linkage, so, say about 3.5:1, 370# at the top of the stick. -- never mind.) I was thinking about proof-testing cables. The AC says (I think I'm remembering this right) load to 60% of rated strength and hold for 3 minutes. 1/8" galv cable is rated at 2000#. So do I have anything that weighs 1200#? Dunno, but I'll bet I could lay my hands on something that weighs 100# and rig a 12:1 lever. Testing to 60% seemed funny until I remembered reading something about designing to 20% of rated stength. I.e. the 2000# cable should not have design loads of over 400#, so the testing is still to triple the design load. Benton +++ #12493 From: "Bruce A. Frank" Subject: Re: proof-testing cables Why do you need to proof test these cables? If the tool crimps the fitting to the proper diameter.... OK, proof test....let's see....do you have a high lift jack? Make a swaged loop and use it to lift the front end of a full size car. Or do you have an engine hoist? Make a loop and lift the front end of your car. If you exert even 500 lbs of force on that cable what part is it fastened to that could stand that force without bending of breaking. Eighth inch diameter cable is actually overkill, from a strength stand point, by at least a factor of 4 maybe even 10. But, let us know the results. Bruce A. Frank +++ #12494 From: Russ and Penny Erb Subject: RE: proof-testing cables I think you'd be re-inventing the wheel. Nicopress claims to develop 100% of rated cable strength when fittings are sufficiently compress as shown by the go-no go gauge. The AC accepts cables created by approved processes without further proof testing (or at least that's what I think it said). However, if you want to convince yourself, go right ahead... I didn't proof-test my cables. Russ Erb +++ #12538 From: "Shawn Burns" Subject: Re: Cutting cable? Hello to everyone on the group. I am building BH535 and finally have something worthwhile to contribute. Regarding cutting cable, there is a tool made to cut bicycle shift/brake cable and housing that would work quite well in this capacity. The name is a CN-10 and made by Park Tool. You can buy it from any of a number of online bike shops or your local bike shop for less than $25. I hope this is helpful. BTW, if anyone is ever in SW Missouri, drop in at ourplace on Woodfield Airpark (MU27). We don't have fuel or a paved strip but you can tiedown at my place for the night. My wife loves to cook and talk flying, too! Shawn Burns +++ #12561 From: "kb8rnu" Subject: Newbie question - Scotchbrite deburring wheels While waiting for my plans I'm trying to assemble the tools I'll need to start making wing ribs. While browsing the reference CD I noticed that a Scotchbrite wheel is used on a grinder to polish/deburr the edges. Can anyone recommend a good source for these wheels, as well as which one seems to work best? There appear to be a variety of grades (coarse to fine) I have a 6" grinder on the way, as that was the size mentioned on the CD. Thanks! Jason +++ #12569 From: Russ and Penny Erb Subject: RE: Newbie question - Scotchbrite deburring wheels Either go immediately to http://www.averytools.com or call 1-800-652-8379 and ask for a free Avery catalog. Great source for most of your sheet metal tools also. I used the 7A Medium grade Scotch Brite wheel, Part #3753 from Avery, $49.00 (not cheap, but if you treat it right it will last for the whole project). They also have smaller ones for doing insides of holes, such as rib lightening holes. Russ Erb +++ #12574 From: Benton Holzwarth Subject: re: Scotchbrite deburring wheels I bought one of the recommended Scotchbrite wheels, but didn't use it as much as I thought I would. I did most of what I needed with a med-fine file followed by grocery store green Scotchbrite pads. Not to take anything away from Avery, but if you're near a decent sized city, look up 'Abrasives' in the yellow pages. Palm Abrasives, in Portland, OR, for instance, has 'em. I don't think it was any cheaper, but at least I saved shipping and had it a couple days sooner. Benton +++ #12576 From: "tim_rickard" Subject: Scotchbrite Abrasives You know I use 3M Scotchbrite abrasives everyday in my metalwork, but I use the 4" discs on my 4 1/2" angle grinder(you need a special holder) instead of the wheel on a bench grinder. So much easier to manipulate than a bench grinder and you can easilly switch between course,medium and fine as needed. I buy them at my local welding supply. Just remember don't use it just before welding aluminum because it leaves trace amounts of "stuff" which can contaminate your weld. By the way... just ordered a set of Bearhawk plans- looking forward to beeing involved in the group in the future. Tim R. +++ #12578 From: "Fred Spain" Subject: Re: re: Scotchbrite deburring wheels For many years I was in the janitorial supply business. 3M invented "Scotchbrite" material as floor pads to replace brushes under floor machines for polishing, scrubbing, and stripping wax from floors, and since then other uses have evolved. The pads are color coded with light colors being less abrasive and dark colors being most abrasive (white, tan, red, green, blue, brown, black, etc). I made my Scotchbrite wheel using a universal floor pad holder, available at any janitorial supply outlet, attached (centered) to a wooden disk with a 3/8ths inch rod glued in a 3/8ths inch hole bored through its center. I spin mine with a drill chuck in a shopsmith. A drill press would probably work too. Go to a janitorial supply store and ask for a universal floor pad holder and a 13" brown thickline floor pad. For less than $20 you will be in business. The floor pad has a 3" circle precut in the center. The circle comes out and is handy for buffing by hand. Some folks might think the brown pad too abrasive, if so go to a lighter color. Most of the cost will be for the pad holder, replacement pads will be cheap. There are also cheaper brands of pads too, like "brillo", generic, etc. Fred Spain +++ #12583 From: "kb8rnu" Subject: Deburring wing ribs Thanks for your replies in response to my question regarding Scotchbrite wheels. The responses indicated you can deburr and polish the edges of cut aluminum with hand Scotchbrite pads rather than the grinder if you wish - is this correct? I'm interested in that because I know a lot of my work will be done after my wife and child go to bed, and before the awake, so noise is best avoided. Does a particular grade of hand pad work best? Thanks! Jason +++ #12584 From: Russ and Penny Erb Subject: RE: Deburring wing ribs Yep, that'll work, even if it takes longer and more effort. I've done that on occasion, especially with wing skin panels too big to run by the grinder. I like the maroon pads, available by the box of 20 from Avery (and probably other sources). The good thing about the maroon pads is that they use aluminum oxide as the abrasive, so there's no concern about dissimilar metal contamination. That, and it seems to be a good compromise in coarseness. In general, I used cheap aviation snips to cut each pad into 12 pieces, each about 1-1/2 inches per side. Russ Erb +++ 12586 From: supermexgarza@a... Subject: (no subject) http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=42195 -- best deburring tool i have used, click on the hyper link and it will take you to a Harbor Freight web page displaying the deburring tool I'm referring to the ones with the red handles the one with the funny hook on the end is for deburring the lighting holes. You will be surprised as the effectiveness of a 3 dollars tool. Javier Garza +++ #12590 From: "handainc" Subject: Re: Deburring wing ribs Saw your comments about aluminum oxide as an abrasive - I was taught to never use an aluminum oxide abrasive on aluminum - you are imbedding aluminum oxidation particles in the piece of aluminum that you certainly do NOT want to oxidize (or to use the common term - corrode)! I always try to use silicone carbide abrasives on aluminum. I was also unaware that the maroon pads were aluminum oxide based - I will be checking all those in my shop. M. Haught +++ #12592 From: Russ and Penny Erb Subject: RE: Deburring wing ribs Don't do anything rash yet--the aluminum oxide comment was based on memory from several years ago and I cannot confirm it. I have trouble with your comment about aluminum oxide being a problem, since any piece of aluminum in the atmosphere is covered with a film of aluminum oxide--it forms from reaction with oxygen in the air and forms a protective coating preventing further oxidation, not to mention melts at a higher temperature than aluminum and thus makes aluminum welding (more) difficult. Adding a little more isn't going to change the corrosion behavior. Embedding dissimilar elements can lead to corrosion. I'll now throw this question over to Lee Erb as I've past the limits of my knowledge and he started this mess anyway. I find it hard to believe there would be a problem when the pads are marketed specifically to people working with aluminum, but that's hardly scientific proof. Russ Erb +++ #12594 From: "Kent White" Subject: RE: Deburring wing ribs Gosh, I am in a quandry over this alox thing. I have been doing polished aluminum sheetmetal work for a long time, and have never seen any deleterious effects from my use of alox abrasives. The carbides are certainly nice, and cut well, and expensive. I wonder how I missed this caveat...??? Has anyone noticed deterioration of sanded aluminum surfaces otherwise unexplainable? I do know that the surface oxidation process of some alloys slows sufficiently over time, enabling the alloy to therefore self-coat itself against corrosion. Kent +++ #12600 From: "Bruce A. Frank" Subject: Aluminum Oxide Abrasives and Aluminum All aluminum has a layer of aluminum oxide on the surface (from moisture in the air) no matter how freshly sanded of buffed. It just gets thicker, up to a point, with time. Aluminum oxide is a stable state and once the layer forms the underlying metal can be relatively well protected. That is one of the reasons for the anodizing process (though anodizing is more than just an oxide layer, it is a hard crystal structure). Different chemical treatments may bring about different states of oxidation, but I have never heard of aluminum oxide abrasives contaminating the metal thus leading to corrosion. The primary reason for Alclad material is to provide a pure aluminum surface layer that forms the protective oxide layer quickly and easily thus protecting the underlying alloy, containing such nasty "contaminates" as copper ( one of many alloy ingredients which promotes rapid corrosion in the granular structure), from destroying the structure in short order. One of the most notable problems with aluminum oxide is in the welding process. Aluminum oxide interferes with the current flow of the welding arc requiring the AC cycle combined with the ionizing effect of the high frequency component of the arc. Aluminum welds best when scrubbed clean with sand paper of silica or silicate (garnet) grit or aluminum oxide. Wipe clean and weld immediately. The other, probably best method, is to scrub with a clean (never used for anything else) stainless steel brush. Some of the worst contamination is caused by using a carbon steel brush (or even worse, steel wool) to clean before welding as particles are imbedded which are not cleaned from the surface by the action of the arc during the welding process. These particles remain after welding and induce galvanic corrosion. Aluminum oxide particles are exploded from the surface in the presents of the arc and any such separate particles that might become entrapped in the weld are inert. Surface imbedded particles of aluminum oxide do not promote corrosion as does (certain forms of) iron oxide on the surface of steel (or on even stainless steel). A heavy layer of aluminum oxide, such as an anodized piece, interferes with the "wetting" process as you dip the filler rod into the molten puddle. Now, as for machining aluminum that has been cleaned with aluminum oxide abrasives...steel cutting tools wear much faster if those particles remain imbeded in the surface after cleaning. Sorry, there I go again. Bruce A. Frank +++ #12604 From: "Bruce A. Frank" Subject: Follow up-Aluminum Oxide Abrasives and Aluminum I didn't intend to imply that oxide inclusions in the weld don't cause any problems. They can reduce ductility, cause lack of fusion and cause cracking. They are just not a cause of corrosion. Small inclusions, pin prick size, of oxides are usually no problem. Carbon, as Budd mentioned, can be a significant contaminate that will cause corrosion pits to develop quickly. Bruce A. Frank +++ #12606 From: "piperthorp" Subject: Re: Follow up-Aluminum Oxide Abrasives and Aluminum AC 43.13 paragraph 6-115 calls for aluminum oxide or garnet paper and not silicon carbide. I have used silicon carbide at times and not seen any ill effects. Maybe because I etched and alodined also. Bill Cox #303 +++ #13643 From: "handainc" Subject: Re: Re: Suggested tools? > I wonder where Sears tools are made. I have looked at some really > nice drill presses at Sears, and on sale they aren't > unreasonable. If you belong to the Craftsman club you can get > additional discounts. Home Depot has a line of Rigid tools that impressed me this summer. A friend of mine bought a table saw, sanders, horizontal belt sander (I LOVE that unit) jig saw and several other pieces that I used helping him with a antique project for several months, and I found them to be of good quality. You might take a look -- M. Haught +++ #13646 From: Del Rawlins Subject: Re: Re: Suggested tools? > It says craftsman on the handle. Since then my powere tools have > shifted to Ryobi and I really like Snap-On for hand tools. Of course > sometimes Harbor Freight works if you are rather careful. I had a Ryobi jigsaw that went into the can the other day, wore out in about 5-6 years of occasional use. I got a Milwaukee replacement for Christmas (I have the best in-laws in the world) that I tried for the first time today. I thought the Ryobi had been nice when it was new, but there was no comparison whatsoever. Personally I think that if a person can't afford a Milwaukee or Porter Cable tool, the only cheaper tool that should be considered is a Makita. Not as nice as the other two brands, but they are built stout and hold up as well as anything. I've read on the various newsgroups about how Craftsman power tools are not what they used to be, but I've got a Craftsman compound miter saw that has been utterly dependable in the 5 or so years I have owned it, which is the limit of my experience with their new power tools. I've had great results with their hand tools with the exception of some of their ratchets. -- Del Rawlins +++ #13653 From: "Bruce A. Frank" Subject: Re: Re: Suggested tools? I have gotten excellent service from Dewalt. Particularly their 18 Volt 1/2 portable drill which I would not give up for anything less than enough money to buy two more of them. I bought a factory rebuilt 8 years ago from Harbor Freight. I have been amazed at its power and longevity of charge. Maybe the factory rebuild of an under warrantee tool made it better than average. It is just the best I have ever owned. I don't even use corded drills anymore. Another Dewalt tool that maybe isn't the most useful for working on the plane but very handy doing all kinds of other stuff is my "Sawsall". I use it, with the appropriate blade, for everything from cutting steel pipe to limbing trees to firewood. I have had it for 10 years and used it most extensively to remove heavy surface roots from 30 hybrid poplars we had in our yard in PA. Cutting through sometimes 5 inch diameter roots with the end of the tool buried in the dirt up to the air vents and it still keeps on working. I owned several Milwaukee power tools when in business and they certainly are the best, but pricey compared to the quality and service I have gotten from Dewalt (not that Dewalt are cheap, just some price savings) Bruce A. Frank +++ #13655 From: Del Rawlins Subject: Re: Re: Suggested tools? The only real gripe I have against Dewalt is that they come in that ugly yellow. 8^) Never used one, but those I have handled at tool stores have seemed pretty well built. Ditto your comments on the sawzall, that will probably be the next electric power tool I buy. Could have used it several times since buying the house. -- Del Rawlins +++ #13669 From: Bob Romanko Subject: RE: Re: Suggested tools? Ditto Bruce. I have the same Dewalt 18V cordless. Nice clutch, heavy, great chuck, Harbor Freight, factory reconditioned. By the way....I learned that Harbor Freight has more factory reconditioned Dewalt than anyone. Factory reconditioned is a SWEET deal folks. It's basically a new tool, and in many cases they are returns, not necessarily broken tools. I recommend the 18V Dewalt to just about everyone. It's one really great drill with plenty of power to do whatever you need to do. There is ONE other tool I used to build my Bearhawk. I cut out my form block with it. There isn't much else to do with it on the Bearhawk, but I used it A LOT to build that rocking horse for my son. That tools is the Bosch 1582VS saber saw. This thing is a HOSS and you really need to use one with the Bosch blades for wood and metal to appreciate it. To give you an idea of the power and control of this tool, I had a steel bracket break on my snow thrower. It was an "L" bracket that the two exhaust bolts went through and was also the top attach point for the heat box around the carb. Anyhow, I decided I wanted to make the replacement out of stainless steel. Only thing was I didn't have any laying around. So, I went to the local Salvation Army Thrift Shop (in Alaska we call that a "Boutique") and bought myself a heavy stainless pot lid in the cooking section. I unscrewed the top handle, put the threaded stem in my vice and twisted that thing off the top, breaking the weld. Here's the good part: I drilled a hole on the edge of the top surface, then took my Bosch with a metal blade and went the whole way around the top of the lid, cutting off the lip all the way around resulting in a big ring. I threw the ring away and beat the top of the lid flat. Then I took my bracket pattern and drew it on the steel and cut it out, drilled it, bent the "L" in my vice with a piece of wood for the radius, and sanded it smooth. Viola! I can't think of another saber saw that could do the job like that Bosch 1582VS did. Guys, it' is a miracle tool that you have to see to believe. I got mine from my dad's estate after he passed away. It has his initials in it, as he did all his power tools. That makes me like it all the more. One thing I've realized with tools, you can't really just say BRAND X is the best brand. You have to look at the individual tool. For the saber saw, I'd go Bosch. For a drill, my 18V Dewalt. For combination wrenches, believe it or not, a cheap, Korean Delta set I bought in an emergency. REALLY! I've used Craftsman, Snap On, S-K, Matco, Mac, etc. Since this Delta set was so cheap, I have ABUSED this set. I mean really bad. 4' cheater bar bad. I have yet to round a fastener, break a wrench, or even scratch a wrench. The finish is like new, and I bought this set 20 years ago. They feel really comfortable in the hand, and clean up well. Not bad for a set I only spent about $12 for back then. Go figure! Man......we can talk tools all day, eh?!? Planter Bob +++ #13688 From: "Kent White" Subject: RE: Re: Suggested tools? The Dewalt 14.4 circular saw is remarkably efficient at making straight cuts in many thicknesses of aluminum sheet, plate, and extrusion. I know of a few fabrication specialists (one in cryogenics) who use nothing else for many aluminum and copper jobs. Kent +++ #13707 From: Del Rawlins Subject: RE: [Bearhawk] Re: Suggested tools? Speaking of Porter Cable, their electric random orbital sanders are simply awesome. Mine made short work of sanding the hull of a stitch and glue canoe I built once. I also have one of their drills and it is wonderful to use. I don't remember how many amps it uses, but it maxes out at only 1200 RPM which makes it ideal for drilling holes in steel and stripping paint in areas that are hard to reach with the stripping pads I use in my angle grinder. My only complaint was a few years ago an internal part slipped out of place, rendering the reversing switch inoperative. I had to take it apart to fix it (which was a major pita) because I needed it then and Cordova is a ways away from the nearest P/C service center. Since then it has operated flawlessly, though if I ever manage to wear it out I will probably replace it with a Milwaukee. I like the cordless tools for drilling holes and use as a power screwdriver, but since I use my drill a lot for rust and paint removal, I don't know how long the batteries would last and I'd rather drag a cord around than deal with the weight and size of the battery pack. -- Del Rawlins +++ #13723 From: "Bruce A. Frank" Subject: RE: Re: Suggested tools? A Dremel Tool is an absolute must! Bruce A. Frank +++ #13819 From: Benton Holzwarth Subject: re: Hand tools > On the subject of good quality hand tools. I've never had luck > getting a phillips head screwdriver that held up worth beans. P-Bob said he got good screwdrivers at Sears about 25 years ago, but when crap tools came up as a topic a day or two ago, I was going to pipe up that theirs went bad in about '85 or so. I think the lawyers made 'em soften 'em up so they wouldn't snap when people used 'em to pry lids off paint cans. The Klein screwdrivers I've used since have been really nice, and I've used their needle-nose pliers and wire cutters since I was a kid. They're what I look for first, when I need a hand tool. I tried Harbor Fright's av-snips. The import ones were slightly better than nothing. They also had a pair of 'Prosnip' brand, made in the US, that I've put a lot of miles on and which are still going strong. And of course, the Wiss ones are great. Another rule, learned the hard way -- I'll never again buy electronic products from Stanley. Two out of three items I tried, of that brand, were poorly made. Benton +++ #13821 From: Drew Schumann Subject: Re: Hand tools I really dislike Snap-On, for a variety of reasons, but they really make screwdrivers that are awesome. If I had to own one screwdriver, that would be the one. Drew +++ #13831 From: Bob Romanko Subject: RE: Re: Hand tools Folks, Snap-on's online now, so shop away! https://buy.snapon.com/_mem_bin/formslogin.asp You need to register to shop, but hey, it beats waiting out in the snow for the truck to show up! Planter Bob +++ #13839 From: shell Subject: Re: Hand tools Best tool I've come across recently is (are?) Malco snips - sold by Avery. I have the 12 inch and they are truly amazing for cutting aluminum stock for ribs, etc.! Much better than offset snips for relatively straight or slightly curved cuts. Shelly +++ #13845 From: "Sharon Theiss" Subject: Re: Re: Wing Rib AutoCAD14 Drawing and DXF Drawing > Do you, or any of the group, know of some kind of a "reader" program > for Auto Cad? Go to www. autodesk.com - do a search for Volo. Volo View is a .dxf reader, it will allow you to open, send and receive .dfx files over the web. And unlike AutoCad 2000 it is free. Scott Theiss +++ #13868 From: Bob Romanko Subject: Who Makes What Tools Here's the best URL to go to if you want to see what's the deal with Kobalt and Snap-on, who makes Craftsman, what the heck happened to S-K, etc. By the way, you'll laugh at the comment regarding "adding his 2 cents" made by the guy who works for Snap-on. It's at the end of the page in the Addendum: http://www.team.net/www/morgan/tech/whotools.html This is a REALLY good URL if you're interested in buying U.S. hand tools, and it sure did answer a lot of questions I had, especially about Kobalt. Planter Bob p.s. Yesterday I used my "old Stanley" #2 Phillips" I said wasn't wearing in a previous post. Well, I took a closer look at the thing and DID notice some slight wear. What does that mean? Yup. Just stick with Snap-on for the screwdrivers! +++ #14005 From: Russ and Penny Erb Subject: RE: Re: Hand tools I'm surprised that no one suggested what I've thought of but never done. Find a handle that will accept the #2 tips that you use for power driving screws. When the tip wears out, throw it away and put in a new one. I've done this with a 1/4" socket, some tape, and a speed handle for driving and removing access panel screws. Russ Erb +++ #14037 From: "Kent White" Subject: RE: Re: Cutting .125 capstrips I do use a Rotozip to cut aluminum, in fact I have 2 of them. One spins at 30,000rpm, the same rpm as the 2 1HP routers I use for wood work and large aluminum jobs. Rotozips have a 30K single speed model, a two-speed 30K and 15K, and a new 4-speed model, 30, 25, 20, 15K. I just got the 4 speed model and with the increased weight of the machine I like the lowest setting for softer aluminum like 3003H14, which mushes badly at the high speeds, like Budd mentions. The hard aluminums, 2024T3 and T6 and 7075 T3 and T6, will easily be cut with speeds of 30K and using 2-edge 1/4" cutters, like the laminate bits. I tend to use the spiral single edge 1/4" cutters on all aluminums at speeds of 15K, but I find the Rotozip does bog down at thicknesses over 1/8", and with cutters over 5/16" dia on aluminum. Using cutters of over 3/8" dia on wood, like making dado cuts, is very hard on the Rotozip as the motor is very light. Edge rounding of lightening holes has been fine for me, though, using the light single-speed machine. Remember that higher speeds with 2-edged cutters are better for hard aluminums and lower speeds with single-edged are better for soft, T-0 and H-0. Some of the old stationary overarm routers used for aircraft aluminum work only turned at 4000rpm, and used spiral 1/8 single edge cutters. One last thought is that I prefer the Rotozip for opening holes and doing freehand work following a marked line. However, it is impractical for attaching a guide to and "shearing" off a long length of material. For that I use a big router (1-2 HP) and use the double rod guide fence with a strip of wood attached as a non-friction strip to ride against the edge of the sheet. Kent +++ #14135 From: "Bruce A. Frank" Subject: Tools in General If you like to browse good tool catalogs, this one aimed at the "metal working professional" take a look at this: http://www.use-enco.com/k_index.cfm?http&&&www.use-enco.com/browse.cfm Bruce A. Frank +++ #15491 From: Russ and Penny Erb Subject: And the 2003 Bearhawk Safety Award Goes To... Pat Fagan! And he didn't even know he entered! What did he do to deserve this award? While helping me mill down my wing strut straps, Pat used a paintbrush that he kept by the mill to brush away the shavings. While I've used a blast of compressed air to blow shavings off, but it's not always available or appropriate. Today I was working on some metal stuff and tried brushing away the shavings with my fingers as I have done for years (works great for sawdust). And, as has happened many times before, a microscopic shaving embedded itself into my finger, creating annoying pain, just like a wood splinter. After removing said shard, I grabbed an old paintbrush (1" to 2" works just fine) off the wall and started using it. Works good, lasts long time, no pain involved. RECOMMENDATION: Every Bearhawker (who hasn't done so already) should dig up a cheap/old paintbrush for chip/shard removal. Russ Erb +++ #17133 From: Sam Butler Subject: Re: Sand blasters > Some time ago there was a good discussion on sand blasters. Budd > recommended buying a pressure blaster, I believe the Truman brand > was mentioned. I am now in the market for a sand blaster and found > out that Truman went out of business last November. Can anyone > recommend another brand of pressure blaster and where to buy it? Harbor Freight has some, I bought one, pressurized, and it works well, it cost something like 80 bucks. Sam Butler +++ #17157 From: "Rod Smith" Subject: Re: Sand blasters I think you mean tptools.com. They no longer have SanBlasters, just cabinet blasters and a small siphon job. Rod Smith +++ #17179 From: "Bruce A. Frank" Subject: Re: Sand blasters > What are you guys using for sand blast media??? I find the 60lbs for $3 stuff from Home Depot works as well as any. Bruce A. Frank +++ #17251 From: 321Tim Subject: Weekly tip angle drilling Jig for Angle Drilling Need to "toe-screw" several pieces together -- driving screws in at an angle, in other words. If you have a lot of screws to drive, wanted to make sure they were consistent. A solution was to make a simple angle-drilling jig (see top drawing). To make the jig, first I drilled a 3/8"-dia. hole in the edge of a 2x6 about 3 in. from the end of the board. Then I cut the corner of the board off at a 30? angle. To create a flat clamping surface, I also cut the "top" corner of the board. When you drill the pilot holes, stop the drill bit just shy of going all the way through the stock. This way it adds a bit more strength. Once you find the perfect depth to drill, use a stop collar on the drill bit to duplicate each hole (see bottom drawing). +++ #17296 From: "doug" Subject: Re: Tool Selection > What scotch-brite wheels/pads are used when? The 3M #048011-01661, 6x1x1 7S Fin, light deburing wheel mounts a 6" bench grinder. Also you'll need the smaller 1x1x3/16 unitized wheels 3M #048011-14063 for deburing the lighting holes. This is a course grade and just right for the purpose, fits on a die grinder attachmant. My sourse was Western Tool & Supply, Livermore CA (925)443-8665 and were much cheaper than either Cleavland or Avery. Check the aircraft catalogs and get a bench mark on the price. I'm going to need a new 6" soon as mine is going on 3 years and getting thin. Doug +++ #17301 From: Del Rawlins Subject: Re: Tool Selection > Ruby / Red / Maroon. You need them way down the road, like when the > parts are near finished. For the pads, yes. The wheels will be useful as soon as you start working with aluminum, for polishing the edges of parts. I have a 6" wheel which I mounted in a buffing motor (a plain bench grinder will work great with the guards removed), which I used to polish the edges of all my ribs. I also have some 1" wheels which screw onto a mandrel, which can be mounted in a drill press or a handheld drill chuck. The 1" wheels are ideal for polishing the inside edges of the lightening holes prior to flanging them (only with a Bob-Stick, of course). -- Del Rawlins +++ #17328 From: Sam Butler Subject: Re: Re: Tool Selection I have found several deburring, polishing, sanding etc. wheels at very reasonable prices at www.americanbuff.com Sam Butler +++ #17463 From: Budd Davisson Subject: Re: Routers > What features should I be looking for in way of a router for cutting > out aluminum pieces? HP? Plunge type? It's not critical. Almost anything works on light stock, even a laminate cutter. It's the bits that make a difference. Two-flute, 5/16 or 3/8 seem to work best for us. bd +++ #17497 From: "Kent White" Subject: RE: Routers > Would you guys suggest using a router (over snips, etc.) for > cutting alu floor panels? I can freehand cut aluminum sheet up to about .100" with the little Rotozip router, using a single flute spiral upcutting bit. Lube the intended path with some sort of oil or beeswax, and the cut should be both stabile and accurate, if your hands are braced comfortably. You may use tape to prevent scuffing of the aluminum surface. It is loud and dusty. Kent +++ #17504 From: Russ and Penny Erb Subject: RE: Routers > Would you guys suggest using a router (over snips, etc.) for cutting > alu floor panels? Snips are good for thin stuff, like .032 and down. On thicker stuff I use a bandsaw and belt sander. I typically only use the router when I have a pattern to follow. Russ Erb +++ #17505 From: bcgh@a... Subject: re: Routers > I typically only use the router when I have a pattern to follow. On the other hand, I inset a piece of angle extrusion into my chapter 1000 workbench (modified to 8') and use it as a straight edge to make long straight cuts with the router and laminate bit, like spars. Note which direction (L to R or R to L) is favored by the cutter rotation direction. I get much better cuts going L to R, since the cutter is trying to stay against the guide. And don't underestimate the value of a little lube. I thought my cuts were fine w/o, but I tried one after running a candle down the cut-line, and it did make a useful improvement, much reduced cleanup on the cut edge. The 1/4" two-flute was having trouble, so I switched to a 3/8" cutter, which worked much better. Having seen the light, re: lube, I should try the 1/4" one again, to see if I could reduce the kerf. Someone asked what features to look for in a router. I'd say, look for one that accepts a vacuum cleaner hose. They do scatter little chips. Benton +++ #17554 From: "Kent White" Subject: RE: Re: Routers on aluminum I have used several different routers (no pireps, unfortunately) and regard the Rotozip as an effective tool for Light Work. What I am saying here is that this little whirligig is very sensitive, the bearings are small, the housing is plastic, and there is very little torque. If the thing is loaded very much, as for instance when using a roundover bit of any size over 1/8 radius, it will bog down, which is Serious. Bogging down creates heat and friction in the tender internals, leading to a shortened life expectancy. Also, any lack of stability when grasping the thing leads to a nasty cycling-up of vibration, especially when doing aluminum sheet. This is bad for the bearings and housing and also for the tender internals. I suppose kerosene would do for lubricating the cut, but it is about the lightest chintzy-est barely-a-lube man can obtain. I use WD 40, 3 in 1, Door ease, beeswax, Marvel Misery Oyl, ATF, and all of these lubes are mighty penny-bleeding products. If you do not use a lube (of any quality) then the cutters load up, eventually turning into a solid polished shank which quits cutting altogether, and then the operator, in his willingness to overcome this minor obstacle, shoves real hard on the Rotozip in an effort to Make it cut. The bearings now begin to warm up and start to soften the plastic case. The sensitive internal geometry necessary for smooth internal rotation is now lost and so now the windings on the motor begin to fry, and the little whiligig eventually stops. Use a good lube. So, use a good lube, hang on tight, refrain from using large cutters, don't push too hard, and the little thing will serve you well. I own 2, a single speed, and the noo 4 speed, (30K, 25K, 20K, and 15K rpms). Slower speeds are better for aluminum. The big old stationary routers that did all of the aircraft production turned about 900 rpms. At least this is the speed the bit designers have told me they designed the router bits to cut aluminum at, using these big old honkin machines. So the choice of cutters for aluminum is based on the router's speed, and the inherent stability (lack of vibration) of said router. Cutter diameter and number of flutes is important. Single flutes can be a smaller diameter for higher speeds. 2 flutes need to be a slightly larger diameter for higher speeds. Routers for wood generally turn at 25K - 30K rpm, so start figuring 2 flute laminates at 3/8 and singles, in a spiral upcutting design at 1/4 to 5/16. Oh, remember to use a good lube. Kent +++ #17737 From: Russ and Penny Erb Subject: Useful Tool--Dirt Cheap Too! I am a big fan of nutplates, which you might guess based on the hundreds of them all over #164. I really like the floating nutplates, because I don't have to be perfectly precise on lining up all of the holes (very useful on access panels). I never got around to buying one of those nutplate drilling jigs, because Dr. Tony (Bingelis) told me that I could just use the nutplate as a drill jig. I've been doing that for several years, but was never totally satisfied with the results. It was tough to center the nutplate when it's floating all around (which is what it is supposed to do). The result was sometimes the holes weren't perfectly lined up. As I was considering spending the $35 to buy a drill jig and wait several days for it to show up, and wondering what I would do about the current requirements, I had the following idea. It is incredibly simple, incredibly useful, and dirt cheap too! Go to the Yahoo! web site and look in the Photos section under Nutplate Jig to see the accompanying photos. I grabbed a piece of 0.100 thick 4130 steel--why 0.100? Because that was the thickness of the first "thick" piece I found. You want it significantly thicker than what you'll be drilling so that the holes will be resistant to wallowing out (if they do, just make another jig--after all, how expensive can it be?). The tough part is drilling three (3) #40 holes in the jig at the proper locations. I used a nutplate for this. If you don't get it quite right, just do it again. My holes are drilled at an angle instead of perpendicular simply because they wouldn't fit straight across. The procedure for drilling for nutplates goes something like this (see photos) 1. Drill #40 hole at the bolt/screw location. 2. Attach drill jig with cleco. If necessary for extra security, add vise-grip pliers. 3. Drill hole for first rivet. 4. Place rivet in hole to prevent jig movement (holes are too close together to use a second cleco) 5. Drill hole for second rivet. 6. Remove rivet and jig. 7. Drill screw hole out to proper size. 8. Dimple holes for rivets and screw. I used this on tabs for about 20 or more nutplates, and all of the holes were aligned as perfectly as on the jig. As a plus, it went much faster than doing it the "old" way. You can use hundreds of nutplates on your Bearhawk--make one of these early and save yourself a lot of heartache and a little bit of money. Russ Erb +++ #17738 From: "Bruce A. Frank" Subject: Re: Useful Tool--Dirt Cheap Too! I also like the floating nut plates and had the same "centering" problem when trying to use a plate as the guide. I fabricated a guide just as you did out of .100" 4130. To keep it from wearing I heated it to cherry red and dropped it into a can of water. It didn't crack. Is as hard as a piece of glass. Rings like a tuning fork and has shown no wear though it has been used by several friends and probably guided 1000 holes. My calipers show no change in dimensions since I made it 10 years ago. Have lost it twice, in fact it is lost for the third time right now, but it keeps coming back. If I'd make a spare it would likely never stray again. Bruce A. Frank +++ #17739 From: Pat Fagan Subject: Re: Useful Tool--Dirt Cheap Too! In a pinch, you can use a K1000, non-floating, nut plate to drill the holes for a floating nut plate. They both have the same dimensions. Pat Fagan +++ #17749 From: "Bruce A. Frank" Subject: RE: Useful Tool--Dirt Cheap Too! > Bruce--before I try this, I need to clarify "cherry red". Is that > with or with out welding goggles, and is that significantly before > the bright yellow of metal that is about to form the weld puddle? "Cherry" red is a very precise metal workers term.....not! I heated it till it was uniformly hot and glowing which is actually above the "cherry" level....yellow hot all over...which is likely close to 1300-1500 degrees F (without the goggles). I can't remember the temperature colors right now. Just short of the melt point. This really isn't a precision operation, I wanted it hot enough to go rock(well C scale 50+) hard when dropped in water (chilled REALLY fast). BTW, for others reading this, this is an abuse of the hardening process of 4130. Any shape of 4130 other than flat can potentially crack when treated this way. Heck, going into water, even a flat piece may crack through a drilled hole. 4130 is considered air hardenable and if you were trying to make a cutting edge (knife or gasket scraper) you'd chill it in oil then do a mild temper on it. After I fished it out of the water can I sand blasted it to remove the scale then oiled it. Bruce A. Frank +++ #17766 From: "Kent White" Subject: RE: Useful Tool--Dirt Cheap Too! Yikes. Sounds like that temp was near to 2000, to me. I like to turn off the bright lights, and set the ambiance of the shop to approximately early 17th century, (as if with the dirt floor and sooty black walls with grimy greased paper covering the "wall-holes"). With the lighting set at that artistic level I see the "cherry" as a dull glow, which is not visible under fluorescents, at all. (Period methods require period settings.) I made this discovery after hanging out with the blacksmith in his "17th century shop". Found out I was missing a bunch of colors that they speak about amongst themselves. I think the lack of lighting does a lot to decipher the code. Straw, brown, purple etc come onto bright steel in good sunlight, but no glow to these. Kent +++ #17773 From: Daniel Gagnon Subject: RE: Useful Tool--Dirt Cheap Too! The temperature to tempered the steel is around 1500-1575 *F and it correspond to a here we talking about a marasquin cherry. P.S.: just ask a student to temper it. ;-) Daniel Gagnon +++ #17774 From: Daniel Gagnon Subject: RE: Useful Tool--Dirt Cheap Too! Excuse me guys not tempering but hardening temperature is 1500-1575. Wenever trust the student and theirs teachers sometime Daniel 598 +++ #17775 From: "Bruce A. Frank" Subject: RE: Useful Tool--Dirt Cheap Too! Probably you are correct (can't find my book). My only point is that it was hot enough to have color (glow in the light) and was quenched in water making it VERY hard. Bruce A. Frank +++ #17778 From: "Bruce A. Frank" Subject: RE: Useful Tool--Dirt Cheap Too! Didn't wanna temper it...wanted it HARD. Bruce A. Frank BTW, guys, I used to work with a couple of knife artisans and a metallurgical engineer in a knife manufacturing business. These guys constantly ran me through the color temperatures and grain structure temps and hardening quench mediums and alloy formulas and temper temperatures. I have a couple of books about it on top of a couple dozen books on weld performance and metal alloy temps. I just don't need to follow this drilling guide process by any book. Just heat it until it is visibly hot with the lights on and the goggles on or off and drop it in a bucket (or can or sink) full of water. Liquid nitrogen would work better but I was keeping it simple (actually, don't use the liquid Nitrogen until after it is tempered...which you're not doing anyway) +++ #17789 From: "Kent White" Subject: RE: Useful Tool--Dirt Cheap Too! > I assume these colors are as seen without tinted welding goggles? You assume correctly about the absence of tinted welders' goggles, Major. Nekkid eyeballs need only apply. Kent +++ #17927 From: 321Tim Subject: Weekly Tip> Pipe Clamp Cradles Pipe Clamp Cradles - Whenever you use pipe clamps, you'll need some way to steady the clamps and keep them from tipping over. [Image][Image] Why not make several "cradles" from inexpensive metal broom clips and plywood blocks (see Photo). The cradles have the added benefits of raising the panel off the clamps, so there's no worrying about the pipes leaving behind ugly black stains on the wood (see Illustration). Tim +++ #18000 From: Arnold Norton Subject: RE: Work table update > clarify--was that $100 per table or $100 for the pair? If the > former, that's inflation. If the latter, that's a reduction from > 1997 ($60 per, $120 pair). > > Another important tidbit--where did you buy the materials? What > store and what city? Geography does matter. That was $103 to be exact and that is for the pair. The material was purchased at Lowes here in Bakersfield Ca. One thing I should note is that the plywood was a 23/32 sanded exterior rather than 3/4 The only 3/4 that they had was a mahogany covered plywood and the mahogany was more than likely the extra 1/32 The way they keep changing lumber sizes, you may soon buy 1/2 and they sell it to you as 3/4 Arnold Norton +++ #18203 From: Shawn Harrison Subject: Shopsmith Today I made the stupid mistake of watching a Shopsmith demo at Lowe's. Dang! Looks like a fantastic tool, and seems to have good build quality. The salesman also said there was a reduction drive for the motor, so you could get it down in the 100 RPM range for steel work with the lathe and bandsaw. What do you guys know about this thing? If it's a good tool, it would seem to be a good deal for nearly all of the shop tools a guy would need to build a Bearhawk -- including the steelworking parts of it. In general, what are the good brands of power tools, and what are the ones to avoid? I'm pretty familiar with the good hand power tools -- I've got a DeWalt drill, a Milwaukee Sawzall, and a worm drive Skilsaw, all of which are outstanding tools. But I really don't know anything about the quality stationary "shop" tools. I sure appreciate whatever thoughts you give. Thanks, Shawn Harrison +++ #18204 From: Budd Davisson Subject: Re: Shopsmith Although I'm certain a lot of folks don't agree, I think the shopsmith is the Swiss Army knife of the tool trade -- it'll do in a pinch but it's always nice to have a dedicated tool to do a job. The problem with a do-everything tool is that it is always set-up to do the wrong thing when you need it. It's far better to have one each of the tools needed, even if they have to be crunched into a tiny space and pulled out on wheels when needed. for the same amount of money you can buy used tools to do everything the Shopsmith does. I have a metal bandsaw, 6" jointer, 10" saw, wood bandsaw, drill press, welding tanks, MIG unit all scrunched into a space about 3 x 5 in the middle of the floor and just work around them, as needed. bd +++ #18205 From: Bob Romanko Subject: RE: tapping question > One local tool company actually sells the tap extractors but > currently only has sets for around $100. He suggested driving some > nail into the flutes and vice-gripping it out. Tip on the 'ol "Nail in the Flutes" trick: Use masonry nails. Planter "Been There Done That...No Fun" Bob +++ #18207 From: "handainc" Subject: Re: Shopsmith I've watched several presentations on the Shopsmith, and have used one quite a bit. They look great, and the demonstrators make them look like the greatest thing since sliced bread. Using one in a shop, I found it to be cumbersome. After using one (loan from a friend) I ended up buying separate tools from Sears and used from various sources (mostly yard sales, all for a lot less than a Shopsmith. I have a great radial arm saw (older Craftsman) for $100, a plane ($50) a tablesaw (Craftsman) , a Twain Drill Press, a router mounted on a table (home built table), a used Craftsman wood lathe($50 used) , and various hand tools. My entire investment is less than half the cost of a Shopsmith, and I can move from one to another without any set up or changing of attachments. I cut a length of wood on the radial arm saw, rip it on the table saw, shape the edges on the router, and if needed. run it through he planer or edger. 10 minutes at most. Metal working, I have a $199 foreign band saw, tanks, torch and cutting torch. Tig welder, hand grinders and dremel tool. I probably have less invested in all of my tools than the Shopsmith, most bought used, except for the Tig, which is a luxury, that I enjoy the most. I've remodeled several houses, built one from scratch, two shops, a hangar with a two story apartment, and with the addition of a metal lathe and mill, worked 7 years as a full time machine shop. The Shopsmith, is just not practical in my opinion. And that is worth just what it cost - Nothing!! M. Haught +++ #18208 From: Sam Butler Subject: RE: tapping question > Okay, P-Bob, I'll bite. Why masonry nails? I'm no P-bob but I've used masonry nails and they are much tougher, and don't bend, very stiff, probably hardened, so will not bend near as easy when put to a tough test like removing broken taps. Sam Butler +++ #18209 From: "Bruce A. Frank" Subject: RE: tapping question They are a lot tougher than standard nails. They are actually hard enough to break if hit wrong. For use as a twisting devise to remove a broken tap they are un-surpassed. They will take just about all the unscrew power you can develop with a pair of vise grips without bending. Bruce A. Frank +++ #18210 From: Bob Romanko Subject: RE: tapping question There you go Erbman.....Bruce hit the nail...errr.r....no...we're not actually HIT'n 'em..... (grin) Bruce, what I've experienced is not only bending, but actually shear. It's REAL easy to shear a common nail if you do the 'ol "Nail in the Flute" trick. Masonry nails work nearly every time, although I have sheared those as well. kay...I'll break clean (pun intended).....I don't use vice grips on the nails, although most folk do. I clamp both nails in a small inverted drill press vice. Makes for a bigger handle, and the whole affair's centered a bit better. My dad left me this vice. It's a U.S. made one from the 50's. I haven't seen one this size since. It's sweet, and really useful. Still, I'll go back to my original post that an actual tap extractor's the best way to go with this situation. You can buy about three incomplete sets for under $100 on eBay, and you'll end up with almost two complete sets if you pay attention to what you're bidding on. Planter Bob +++ #18212 From: "Fred Spain" Subject: Re: Shopsmith I have a ShopSmith and I love it. It is a quality tool. Their advertisements say you can change functions from anything to anything in less than a minute and this is true as long as you keep all your accessories organized. I have an imported drill press which I use 95% of the time, but the ShopSmith has 4" of travel instead of 3" on the import, and at times that extra inch makes all the difference. The horizontal drill press feature also is real handy at times. Remember the little wooden block tools on Russ's CD used to center a 1/4" bit in a 3/16" hole, used while making the form block. I made several variations of these easily with the horizontal drill press. The 12" disc sander is the handiest thing since sliced bread. I have 1 disc with course paper and another with finer paper. I'll cut both wood or aluminum down to rough dimensions then sand down to finished size. It was great on the form block, spar 1/8" plate material, to shorten rib length, etc. I had a cheap jig saw which wasn't worth a dang. I replaced it with the ShopSmith attachment and the difference is like daylight and dark. It is real quality for wood and aluminum. The variable speed is a real good feature. I don't know about the speed reducer and use with steel. I use the Harbor Freight bandsaw on metal. Also, I've got a 10" craftsman table saw which I use 95% of the time, but the ShopSmith is about 6' long and with the little "tables" mounted at each end I can cut across very wide material that would be clumsy as hell and require an extra pair of hands on the craftsman. Also, the ShopSmith is real easy to clean compared to the craftsman. It is the only wood lathe I have and I haven't used it much but I like it. I made a set of "dies" for flanging lightening holes but decided the "Bob Stick" was the way for me to go. You can also do some router work with it but I have never tried that feature. I am so impressed with the ShopSmith that I just bought a Smithy Granite 1324, 3 in 1 metal working tool. It is a combination lathe/mill/drill made by a different company, who also makes a woodworking tool copied after a ShopSmith. The Smithy just arrived this week and I don't have a clue how to do anything with it, but I will unpack it and begin setting it up on this rainy day. I am starting out with several of their accessories and there are a lot more available after I learn what to do with them. I did get several of their educational manuals. Remember those words of wisdom from some wise person, "BUILDING AN AIRPLANE IS AN EXCUSE TO BUY TOOLS" Bearhawk #402 was progressing nicely last fall (spar construction) until the bitching got so bad that I had to postpone my project to build an addition on our house. I'm doubling the size of our bedroom, adding a new kitchen/dining room, a screened porch, and triple carport. The carport will join the house with my shop. I will be able to go and come in the rain without getting wet. Another plus is that my shop, 1350 sq. ft., got a 5 ton air-conditoner. Once this addition is complete, I will have a comfortable place to build #402. Since Cleveland, MS, best described as an island in the middle of a rice paddy, may well be the mosquito capital of the world, the screened porch may help protect us from the West Nile Virus. The mosquitos own this place from dusk 'til dawn. Viva ShopSmith!!! Fred Spain +++ #18218 From: "Merle Wagner" Subject: Re: Shopsmith I have had my Shopsmith for over 20 years and it has been one of the best general overall tools I have ever purchased. I have remodeled over 5 homes with that unit. You folks are correct in that having all the separate tools is the best way to go but.... when you have minimal space and no money I would recommend the Shopsmith in a heartbeat. If you need a tool that can just about do everything. Now that I have a hangar full of goodies I still find myself using the Shopsmith. Today I was working on my flaps...cutting AL, plywood, gluing, drilling and the shopsmith was sitting there with the sanding disc running just fine. Merle +++ #18220 From: "handainc" Subject: Re: Shopsmith Hey guys, don't get me wrong from my former post - I loved the Shopsmith I used. I just couldn't justify the expense and the changing process from tool to tool - plus the one I was using was probably older than I am! I'm sure they have been improved since then. I still have am fascinated when I see a demonstration. If I ever get rich, I will probably buy one just to play with!! And space considerations are important. M. Haught +++ #18227 From: 321Tim Subject: Re: Shopsmith Grizzly Tools has a similar lathe combo, only differnece is twas priced around $899. They had a big display at Arlington about 3 years ago. 321Tim +++ #18228 From: 321Tim Subject: Re: Shopsmith Grizzly Lathe $795. Link/Jpeg> http://www.grizzly.com/products/item.cfm?itemnumber=G4015Z 321Tim +++ $Id: 3.1.8-Tools-Other,v 1.16 2003/05/22 04:07:10 bentonh Exp $