+++ #3381 Subject: Novice Metal Man Johnson with Questions From: William & Delinda Johnson Just viewed Kent's video on shaping wheel pants. Good stuff! Kent, at the end, you show making a panel using the machines. I watched with great interest your process. Here are my observations: 1. You seem to use the power hammer for basic shaping 2. The wheel was used to smooth out the panel after using the hammer 3. After smooth, you test fit on the buck 4. On occasion, you went over to another power tool which I could not identify. Seemed like a power stretcher & shrinker but I am not sure. Question 1: What was that tool???? Question 2: Why do you use the spring steel slapper instead of the oak slapper? Question 3: The kick type shrinker & stretcher leave marks where the dies grab the part. How do you get the marks out once the panel is fit to the buck. +++ #3397 Subject: Re: [Bearhawk] Novice Metal Man Johnson with Questions From: Kent White > Question 1: What was that tool???? I THINK YOU ARE REFERRING TO THE "GREEN SEWING MACHINE?" IT IS AN ELECTRIC RECIPROCATING MACHINE, "NIBBLER", OF THE PULLMAX-TYPE, WHICH I HAVE FITTED WITH SHRINKING DIES. SINCE THAT TAPE WE HAVE DESIGNED SHRINKING DIES FOR THE AIR POWER HAMMER. > Question 2: Why do you use the spring steel slapper instead of the > oak slapper? OAK IS FOR SMOOTHING, TRUE, BUT THE STEEL UNIT SMOOTHS SMALL STUFF TO A HIGHER DEGREE. > Question 3: The kick type shrinker & stretcher leave marks where > the dies grab the part. How do you get the marks out once the > panel is fit to the buck. URK!!! SANDING IS THE ONLY WAY AND THAT THINS THE METAL AND REMOVES CLAD--SO-- AVOID MARKS BY USING CLOTH-BACK ABRASIVE AS INTERMEDIARY. SANDWICH PART IN 220 GRIT WITH CLOTH OUT, MACHINE GRABS CLOTH, GRIT GRABS METAL. BOEING LIKES IT. +++ #3655 From: Float-By Shooter Subject: Re: [Bearhawk] I'll never foget old whatstheirname, plus door ideas > How about making the whole bottom door half fold inward with the > upper door half as it opens outward, hinged at the top? I think I > would leave the window installation just as it is, or perhaps a door > system like this would make it not necessary to open the window > separately. I'd thought of that too, because I want the upward opening seaplane style doors on my Bearhawk. At the top you would want a gas strut to hold the whole thing up, and then maybe some kind of goofy linkage to automatically fold the lower door in enough to clear the strut, or even a bungee cord. I wouldn't want the lower door just hanging down when the door is open however since I might (would) hit my head on it. +++ #3667 From: Subject: Re: [Bearhawk] door ideas Door Ideas? I still plan on the bottom section as a lift out piece. Unable to think of why I would want to open the bottom half in flight. If I really need to get the door gone........jettison it. +++ #3670 From: Ralph Obendorf Subject: Re: [Bearhawk] door ideas I am considering a "gull" type door using a gas strut to assist opening and hold open for entry-exit. Any other ideas are more than welcome. +++ #4447 From: budd davisson Subject: Re:Kit Seats, tailwheel springs, windows To answer the questions asked: The new window shape is slightly larger and more rectilinear and uses bent-up "U" channel which is much easier to work. Bob actually paid us a compliment by saying he liked the new shape better than the original one. We know that taste in window shape is at least as subjective as our individual tastes in women, so don't give us a ration of you know what for this. Jpeg is attached. +++ #4455 From: "Rod Smith" Subject: Budds Kit Windows I really like your window design Budd, it is just what I had in mind. How do you make the sharp bends in "U" channel. If it is complicated, is there any chance you would sell the window channels sometime down the road? +++ #4472 From: budd davisson Subject: Re: [Bearhawk] Budds Kit Windows Re: deep U-Channel. It might be available elsewhere, but we're punching the material into a deep die and making them in lengths that are convenient to work. The radii at the corners are actually pieces of flat stock welded in as fillets. The back of the window goes all the way to the member that forms the back of the rear seat. As for making the U-channel material available, we haven't thought that far ahead. We'll let you know. +++ #4503 From: Russ Erb Subject: Re: [Bearhawk] Budds Kit Windows I looked at Pat Fagan's rear window frames (made per plan) and they were looking rather difficult to weld with a good final result. Pat told me horror stories of the thin metal moving all over the place with a mind of its own. Reminded me of what I would expect to find watching Planter Bob work. My initial reaction to budd's drawing is that I think I still like the old window shape better. Therefore, I'm wondering if there is a way to take the original shape, budd's idea of U-channel (which shouldn't be that hard to bend up), and an idea stolen from Kent White's great articles in Sport Aviation, put them in the great particle accelerator, smash 'em together, and get a usable idea out. I tried it, and here's what I got (after cleaning up the mess of products of combustion and some of budd's media blasting sand that managed to make its way over here to California): Trying to put both sides of the channel in a metal shrinker to form the curve wouldn't exactly work. Why not take the U-channel, cut V-notches in the side, bend the channel into shape, then weld the cut sides back together. The weld bead could be ground down flat since there would not be much stress here. I wouldn't know if this was really more work until trying it. Anyone got any slings and arrows of outrageous fortune to hurl at it? +++ #4509 From: Kevin bearhwk272@a... Subject: Window frame forming With respect to Russ's comments on how to form the rear window frame. Stretch form the pieces as large as possible then weld. Obtain a piece of old junque flat steel plate .250 thick Cut to shape of window. Dress down the edges. Mount shape solid in a vertical orientation. Cut several long strips of frame material. Two man operation, solid tack weld the strip to the edge of the tool. One person applies tension to the strip and keeps the center of the strip on center of the form edge. Heat the strip with the torch till dull red. Tap the strip over the form edge. Use a "U" shaped block. Heat areas that form a big wrinkle till orange and then hammer weld them down. Keep working along as far as possible. Repeat the process until you have formed the shape. Then splice weld the pieces together on the form and dress it down. I think that 3 sections will do each rear windows. +++ #4512 From: Tim Subject: Re: [Bearhawk] Budds Kit Windows Question for Benton at Bottom Bob Barrows has a good eye for lines. The BHawk is a dam good looking airplane. It has Piper & Cessna round/square lines for a very nice look....A small change like a window can add or detract from a design.....I like Budd's square rear window, but think Bob's round rear (I said Pardon?) window, flows nicer into the tail....I imagine you could square off the Vert Stab/Rudder some more and it would look closer to a Kitfox and square windows would rule......Wonder what that would look like? and the M-14 radial engine in a round cowling you guy's were talking about last year???....Hey Benton, can you load Budds drawing into MS paint or some other 'simple' program so we can play, designer????. +++ #4519 From: budd davisson Subject: Re: [Bearhawk] Budds Kit Windows Bob's rear windows are made by cutting flat pieces of sheet metal into 1" strips that form the inside and outside shape of the window and then joining the pieces to form a "U" by welding them to a piece of rod that forms the bottom. Not difficult but labor intensive. Good welding practice with a small tip for a tiny bead. +++ #4524 From: "Robert L. Thomasson" Subject: RE: [Bearhawk] Budds Kit Windows > I'm thinking that when I get to that stage I'm going to cut > flat pieces of sheet metal into 1" strips to form the inside > and outside shape of the window, then join the pieces to form > a "U" by welding them into a piece of rod that forms the > bottom. The only minor drawback I can see is that the 1/4" metal rod will not pass the Steve "Every pound is made up of 32 half ounces" Wittman excess weight test. I kind of like the Erb-White snipped U-section method, or Kevin's hand-forged-over-a-quarter-inch-thick-blank method, although it seems like it will require developing some real blacksmithing skills. +++ #4531 From: "Kent White" Subject: Re: [Bearhawk] Budds Kit Windows > Why not take the U-channel, cut V-notches in the side, bend > the channel into shape, then weld the cut sides back together. > The weld bead could be ground down flat since there would not > be much stress here. See Kevin #272 post, Russ. He knows the right method of "blocking" (making with a from block), but don't waste 4130 sheet on it, use 1018 mild. And don't ry to heat up your hammer to "weld" with. +++ #4532 From: Benton Holzwarth Subject: Budd's window image (was: re: Budds Kit Windows) > Hey Benton, can you load Budds drawing into MS paint or some > other 'simple' program so we can play, designer????. It's just a jpeg, should be dirt simple. With Netscape, go to the original post -- http://www.egroups.com/message/Bearhawk/4447 and (assuming you don't have 'autoload images' turned off) there'll be the drawing. Put your mouse over the image, and do a "right-hold" and release on the 'save image as...' entry. Complete the path info, and it's on your disk. Since it's a 'bitmap' image, if you scale it up, the lines will get fuzzier. Don't know if paintshop has image-sharpening filters, but any photo-manipulation program will. If your paint program doesn't have the filters you're after consider d/l'ing 'The GIMP' (The Gnu Image Manipulation Program). It's free, and available for both MS-Windows as well as various unix flavors. (See www.gimp.org) +++ #4535 From: chris hoppe Subject: Re: Budd's window image (was: re: Budds Kit Windows) If that doesn't work, let me know. I can do a vector-based autotrace so your image will be scaleable. +++ #4537 From: "Kent White" Subject: RE: [Bearhawk] Budds Kit Windows > I kind of like the Erb-White snipped U-section method, or > Kevin's hand-forged-over-a-quarter-inch-thick-blank method, > although it seems like it will require developing some real > blacksmithing skills. OK, blacksmithing aside, make the strips with enough on the side for bending 1/2 way across the bottom of the channel. Now chonk away with the Lancaster to shrink the curves, with the idea of keeping the strip flat. When the chonking gets tough, simply switch to hammering the opposite side to stretch it. In this fashion, by alternately stretching one side, and then shrinking the other (yes, the halfway point down the middle of the strip is a guide), the strip lays flat (with persuasion) enough for the second forming operation. Which is: Mark a line down the edge to be turned 90deg. Gently knock the edge over a die or dolly or tool with a plastic hammer. Any small deviations are then "tuned up" with the chonkers. Line up the formed halves to fit, tack, adjust, and weld. +++ #4555 From: "Robert L. Thomasson" Subject: Re: [Bearhawk] Window frame forming It occurred to me that it might be even harder (assuming the goal is to come up with the most challenging method of coming up with an organized group of molecules that resemble a window frame) to take a 3/8" or so OD length of steel tubing and bend it (perfectly, of course, with no kinks, using techniques known only to ancient Egyptians) to the shape of the window frame. Then, with a cutting or grinding wheel in a die grinder, cut away the inside, so that you end up with sort of a C section with a 1/4" ID rather than a U section. The C could be flattened over Kevin's 1/4" form plate, or left as C shape. The major drawback I see is that the channel using tubing might be borderline as far as depth goes. +++ #4558 From: "Rod Smith" Subject: Re: Window frame forming > It occurred to me that it might be even harder (assuming the > goal is to come up with the most challenging method of coming > up with an organized group of molecules that resemble a window > frame) to take a 3/8" or so OD length of steel tubing and bend > it... What you describe is sort of the method used by someone who provides rear window frames to the local outfit that builds new Super Cub fuselages. The difference is that they use larger tubing (maybe 3/4") and it is flattened so that it is a uniform 3/16th or so on the inside. They obviously have some sort of form they work it over. The odd thing is that they use stainless tubing, I have no idea why. This is then Tig welded to the 4130 tubing of the frame. I dont know if you could get a good weld with gas or not. Actually they look pretty close in size and shape to Bob's design but mine will look more like Budd's. If someone is interested I could find out who they get them from. +++ #4559 From: "DANFORD, GARY" Subject: RE: [Bearhawk] Re: Window frame forming I'm sure they use SS because water will run from the window into the frame and rust out. The question is: Can you Silver solder SS to the 4130 tubing? +++ #4561 From: "Bill Cox" Subject: Re: [Bearhawk] Re: Window frame forming There are many types of SS, but the grade used for exhaust systems will O/A weld very easily with mild steel rod. +++ #4565 From: charles.k.scott@d... Subject: Re: [Bearhawk] Digest Number 278 > The odd thing is that they use stainless tubing, I have no > idea why. This is then Tig welded to the 4130 tubing of the > frame. I dont know if you could get a good weld with gas or > not. Shouldn't be a problem, you can use the same rod to weld stainless tubing as you use to weld 4130. But you end up with a weld that will rust. At least that's what Tony Bingellis said. +++ #4573 From: budd davisson Subject: Bob's window frames Now that I've sat back and watched everyone's ideas about how to form Bob's window frames, I think he has the best system. Yes, it has a bunch of bandsaw work for the frames but they are 1018, so they cut quickly. There's also a lot of welding for the base of the channel, even so, this approach looks more fool proof than the blacksmith approaches. However, to keep it straight, while welding, tack it like crazy on both sides of the rod used for the bottom, then, while welding, weld an inch or two on one side and repeat the same thing on the other side. Otherwise you're going to wind up with something that looks like a curly-fry. That's okay too, just remember where you left your big mallet. +++ #4576 From: "William & Delinda Johnson" Subject: 023 Update I have been lurking for the past 4 weeks without a post! So, here goes: 1. Media Blasting - I use walnut shells and glass beads. It works so I keep doing it. 2. Welding - don't weld more than is necessary. For instance, my washers which keep the spring on the support frame are just tacked in four places. The spring will break before those tacks come apart. Use some judgment; however, don't under weld in a effort to make it look nice either. 3. Window frames - Follow Bob's lead - he has found the easiest way to get things done. 4. In all cases, the Nike shoe slogan applies, 'Just do it!' +++ #4579 From: "Kent White" Subject: RE: [Bearhawk] Re: Window frame forming > I'm sure they use SS because water will run from the window > into the frame and rust out. The question is: Can you Silver > solder SS to the 4130 tubing? High quality-25% AG or better- will do very nicely. +++ #4618 From: Corky Scott charles.k.scott@d... Subject: Re: [Bearhawk] Digest Number 279 Here's a question I've been mulling over for a while. Though I'm builidng a Christavia, I think the window treatment is similar. I'm not sure how to finish things at the window. With the Christavia, you have to build out the door frame to match the width of the stringers so that when you wrap fabric around the door frame, it's flush with the stringers. So far so good. The tubing that forms the windows also needs to be adjusted to match the fabric, which is dictated by the stringer width. The way I did this was to lay a long straightedge against the top stringer and against the top of the cabin. This gave me the distance out to which I had to build, or fir, to make the transition look reasonable. I then bent up a bunch of three sided pieces about an inch wide and matched to fit the tubing and welded them in place such that they were close to the plane of the straightedge. Then I bent up some aluminum sheet to match the little rectangles I'd just welded on and slid that around them. This formed the frame around which the fabric will be glued to form the outline of the window. It's actually a bit more complicated than that since the straight edge and the stringer and the top of the cabin change dimensions as you get towards the back of the cabin. Eventually their isn't much need to fir very far. Anyway, now that I have these window frames, what happens when I cover with fabric? The fabric will have to wrap around the frames first, then I'm going to have to bolt or glue the frame onto the fabric which is glued to the aluminum. What's the frame? Metal? Wood? How is the plexiglass installed? Glued into a bevel or cutout? Wood might actually work here because I plan to screw a cover plate around the window, but I gather by reading the last several issues that the Bearhawk uses a metal frame. Sorry to be rambling. +++ #4620 From: Benton Holzwarth Subject: re: window framing > Speaking of window framing, I never did get to see the picture > of the window frame. Can someone direct me to where it can be > viewed? If this is in the Bearhawk website, what is involved > in signing up? Budd's drawing was attached to post http://www.egroups.com/message/Bearhawk/4447 +++ #4657 From: "Float-By Shooter" Subject: FAQ update The Bearhawk steel list in the FAQ has been updated to include "T" numbers as used on the plans (where applicable). Thanks again to Rod Smith (who compiled the list) and Russ Erb (who converted it to html and continues to update it) for making this time saving resource available. +++ #4692 From: Pat Fagan pfflyerz@c... Subject: digging out from under the pile of postings That's nice I was able to help generate some talk on window channel forming, wish I had the benefit of some of that info prior to undertaking it myself. Some things I discovered: 5/32 welding rod is hard to come by, but not impossible, keep looking. I used shrinker/stretchers to get the 1 inch strips to proper shape ( Not knowing any better, I used 4130) I then tacked the two strips to the weld rod every inch, skip welded all over the place, and still had to heat, bend, and hammer weld the puckers all over the place to get it back to the desired shape. Tried a different approach on the second frame. Shaped the strips with the stretcher, then welded one side completely to the weld rod. After getting this assembly back to shape with the shrinker I welded on the other side. It didn't matter, I still ended up having to work it back into shape just like the first one. For those going with the cargo door option, a helpful hint. I installed my rear window on the pilot's side, per the plans, then made a contour pattern out of cardboard so I could match the lines on the cargo door side. After completing the forward cargo door, I discovered I couldn't install the window to match the other side due to the constraints of the door itself, so I installed the cargo door's window, then cut out and reinstalled the pilot's side to match. +++ #4693 From: Kevin bearhwk272@a... Subject: Mass produced fittings Status In response to another flurry of questions on fuselage fittings. Here goes. Plodding along a little at a time drawing all the details in CAD and nesting the parts into sheets. I am doing all the tool path generation so that my supplier will minimize his setup costs. I have completed the tail section and am working in the controls area. There were enough positive responses that my supplier wanted to give a hard cost instead of a ballpark, therefore I now have to provide all the details so he can arrive at exact spindle time and therefore cost. Better for us to nail the cost down, better for him to keep from loosing his tail. It will be at least a few months away before posting a finished package price. Then we will take a head count. The plan is to collect the YEA's, order the parts, then wait until the shop has some slow time. This way he can use this job to fill in and keep a machine going and an operator on the payroll. This means that we do not pay premium price. I for one, have much to go before needing fittings and am working to an elastic schedule. +++ #5299 From: Pat Fagan pfflyerz@c... Subject: Re: [Bearhawk] Snoozin... I have actually investigated the sleeping postion in my fuselage and I think it might be a little tight. I intend to make a flip up door on the bottom of the rear wall to allow my feet to extend beyond the baggage compartment. I will put in one more floor panel and probably mount the battery in fuselage center at the end of that bay. The sleeping angle thing is not a problem. Looks like a very comfortable way to go for two "close" friends. +++ #5446 From: Pat Fagan pfflyerz@c... Subject: floorboards I realize not many of you are at the point of installing floorboards yet, so you might want to file this away for future reference. I studied Mike's photo log and Russ's CD to determine where I wanted to put attachment tabs, then drew up a location map. I welded the last ones today, I think I made 96 and it looks as if I have a couple of dozen left. Anyway, the last section I did was the the panel under the control sticks. From the CD pictures of Proto 2, I saw Bob had a floor mounting screw between the stick attach bracket and the centerline tube above the shock strut bracket. I wondered why, since the stick bracket bearing mounts above the floor and is more than enough to hold the floor in place. After comparing floor pictures of Proto 1 and 2, I finally realized that in Proto 2 Bob made a large cutout for access to the tops of the shock struts, and covered that hole with another piece of aluminum. This access cover is mounted with the two screws on either side of the fuselage centerline, and by one screw just ahead of the flap control arc. In Proto 1 he has a round access cover on either side of the centerline. I like the method he used on Proto 2. Thought this might be useful and save you some head-scratching, Lord knows there is enough of that to last everybody. As for the picture of the tubing beader, not only don't I have a digital camera, I couldn't even get the film job to work the other day. I will send Mike a drawing which will show the parts better than a photo would. +++ #6454 From: "Kent White" Subject: RE: [Bearhawk] Re: skylight shades I was in Jim Wright's GlasAir V for a round trip to Oregon last week. His shades are of an odd translucent fabric that mystically adheres to the canopy, and can be pulled off and wadded up for stowage. They cut the sun very well. Kent White +++ #6456 From: Brian Cox Subject: RE: [Bearhawk] Re: skylight shades Sporty's sells an item called a "Slap On" Sun Visor. Similar in concept, but it is transparent green. We have some for our plane, and also use it on our new Beetle. It has a lot of glass and undersized visors. I think a lot of the stores that sell child seats and the like have various kinds of sun shades. Most just use suction cups, but I've seen a rollup type. Maybe a standard sized one would be helpful in planning the size of skylights in the Bearhawk. Brian Cox, #478 +++ #6457 From: "Mike Carriere" Subject: Re: [Bearhawk] Re: Float Installation Can anyone help us with this problem? #463 and #469 fuselage's are finished as per dwgs and we would like to add more vertical area to compensate for the floats. I believe there is a formula to calculate the required vertical area but can't seem to find anything. We have heard that a 15% increase is required but we don't really understand if that's a guess or a calculation. We have also welded the fixtures in the stabilizers to allow fins or tombstones to be added but would prefer to just enlarge the fin. Thanks Mike #463 +++ #6458 From: "Tim Anderson" Subject: RE: [Bearhawk] Re: skylight shades My kitfox has a one peice window/skylight, very good vis...very hot in texas in the summer. I bought a cloth rectanglular sunscreen at the local autoparts with a loop spring. curl it up in the winter, through it in the back. maybe not as convienient as a roll blind that one can adjust as needed when flying. I do need to add a visor, that's on my wish list. Tim +++ #6461 From: rsmith@a... Subject: Skylight Shade At Sun and Fun there was an RV-8 with a gold colored canopy. I asked the builder about it. He had it coated by some sort of electrostatic process where actual gold is deposited on the plexiglas. Expensive, but it cuts the incoming solar radiation by 80% if I remember correctly. Still pretty good visibility through it, certainly good enough for a skylight. He said the downside in the RV-8 was that it also attenuated EMI, no using a handheld radio without an external antenna. Somewhere in my notes I have the phone number for the place in California that does it. I would definitely at least use tinted plexiglas, but I dont know how effective that is in cutting solar radiation. Rod Smith #246 +++ #6463 From: pfflyerz@c... Subject: Re: [Bearhawk] Trim Wheel Location and Skylight I had been waiting to make an announcement, but since you brought it up, I am happy to announce that I have completed the modifications on my trim system and skylight and am very happy with the results. I spent a LOT of head scratching time working out the details of the skylight. Part of the problem is the hump that Bob has on his two aircraft (see Russ's CD). Fitting a skylight to the hump would be problematic. I finally realized that the hump is only there to allow room for the large Cessna trim wheel. Design a different trim system and you can run a window even with the tops of the wings. I used to do a lot of glider towing in a Bellanca Scout and always liked the trim lever it used. It was possible to fly the airplane in pitch using the trim control instead of the stick. I have actually landed the Scout without my hand on the stick just to see if it could be done, the trim tab was that responsive. I thought I would like to have the same capability on my Bearhawk, elevator cable failure, no problem. I made up a trim lever that mounts to the back of the large tube between the front spar mounts. A pushrod then goes to a bellcrank mounted to a bracket welded to the tubing "X" between the main and rear spar. All of this mechanism is hidden by an aluminum console that is about 6 inches wide (side to side) and rises to meet the skylight panel. There is room in the console for mounting cockpit/ courtesy lighting or even the intercom jacks. Without the large trim wheel I was able to make my skylight even with the upper wing surface and run it from longeron to longeron. You could make the skylight back to the rear spar, but I chose to terminate mine at the tubing "X". This puts the back of the skylight just behind the pilots head, which should provide enough utility. Modifications for mounting the skylight include: Welding a strip to the top of the windshield top channel to mount nutplates for attaching the front of the skylight. Welding an approximately 2 inch tall channel, with nut plates, to the top of the tube the trim lever is attached to. This serves a midpoint platform and attach point for the skylight and also a mounting surface for the trim console. Welding a 3/4 inch tube between the longerons and the "X" member. To this tube is skip welded an approximately 3 inch tall bulkhead with a groove similar to the one the front windshield slides into. This makes the rear wall of the skylight box and also provides an attach point for the trim console. A half X half inch angle skip welded to the wing contours on both longerons to provide a groove for the skylight panel. My skylight panel will slide into these grooves, from the front, and will be attached with a strip over the windshield/skylight junction, and another 6 inch wide strip, from front to rear, over the trim console. A couple of unforseen but useful results of this system are: An extra handhold for climbing into the front seats. The forward tubes of the "X" are no longer covered by the ceiling fabric. I intend to use sight gauges and discovered in fitting my tanks that the first third of the gauge is hidden under the ceiling fabric. With the open skylight box the entire sight gauge is visible. Pat "happy to finally have that problem out of the way" Fagan #232 +++ #6470 From: dewcraft1@a... Subject: Tinted Lexan / Skylight Another option for skylight material, not yet mentioned in this discussion I believe, is tinted Lexan. I've used Lexan (brand name) or similar, for windshields and skylights on several planes. It works beautifully to protect from the sun but allows undistorted vision without the hassle of moving shades etc. Lexan cuts like plywood, it's impossible to crack, and can be purchased from a local plastics supplier in several thicknesses with "bronze" or "gray" tinting. "Clear" is always available, of course. Another advantage to the tint - very snarky / stealth looking! Wicks has it listed in their catalog, last I checked but freight can eat you up. Best to buy locally, if possible. Look into it before making your final decision. My experience has been very positive all 'round. Jim, #440 +++ #6844 Date: Fri, 13 Jul 2001 22:08:24 -0700 From: Russ and Penny Erb erbman@ Subject: RE: Re: windshields > Hey guys, > What are the specifics of the 172 windshield most of you guys > are using. What year, width and thickness? From the July 2000 Bear-Tracks: "BEARHAWK Windshield We have had a couple of phone calls about the windshield needed for the BEARHAWK. Order from LP AERO PLASTICS INC. 1086 Boquet Road - Jeannette, PA 15644. You can contact them directly at 800/957-2376 or 724/744-7372 (fax). Ask to speak with George. Be sure to order Cessna windshield for BEARHAWK #312 or #312.187. #312 is 1/8" thick and #312.187 is 3/16" thick. DO NOT ORDER #312CON or #312CMB!!! The CON and CMB are more expensive and have an extra plastic strip glued along the top edge and will not fit. If you have any questions give us a call or deal directly with George at LP AERO. " Easily found on the Bearhawk CD... Erbman +++ #6980 Date: Mon, 23 Jul 2001 15:33:11 -0000 From: bcox@ Subject: Re: RE :WINDSHIELD > HI HAS ANYONE HAD A LOOK AT SUPPLIERS OF WINDSHIELDS FOR THE > BEARHAWK. Price for the LP Aeroplastics #312 windshield for C-170, 1/8" thick is $202 from Aircraft Spruce. Brian Cox, #478 >>> 2mar02 #7686-9153 +++ #8846 From: Russ and Penny Erb Subject: Alternate Means of Compliance: Rear Window Frames I have successfully constructed a rear window frame by an alternate means. I liked the round rear window of the prototypes, and went looking for an alternate way to do it from what was shown in the plans. Pat Fagan told me about having all sorts of trouble getting his to come out right when built to the plans. I thing my method is easier--at least it came out right the first time without more than a couple of adjustments. In short, .032 sheet is bent around angle iron into a channel. The sides are notched and welded back together. Pix and more details at http://www.eaa1000.av.org/pix/erbpix/erbpix.htm#window_frame Russ Erb +++ #8866 From: Fred Spain Subject: windshield Can any Cessna 170 or 172 windshield be made to fit the Bearhawk or will only a specific model fit? Fred Spain +++ #8871 From: Russ and Penny Erb Subject: RE: windshield >From the July 2000 Bear-Tracks: "BEARHAWK Windshield We have had a couple of phone calls about the windshield needed for the BEARHAWK. Order from LP AERO PLASTICS INC. 1086 Boquet Road - Jeannette, PA 15644. You can contact them directly at 800/957-2376 or 724/744-7372 (fax). Ask to speak with George. Be sure to order Cessna windshield for BEARHAWK #312 or #312.187. #312 is 1/8" thick and #312.187 is 3/16" thick. DO NOT ORDER #312CON or #312CMB!!! The CON and CMB are more expensive and have an extra plastic strip glued along the top edge and will not fit. If you have any questions give us a call or deal directly with George at LP AERO." That's the extent of my knowledge. Russ Erb >>> 20may03 #11298-18250 +++ #12205 From: Russ and Penny Erb Subject: Bottom stringers stop short? If you have the fuselage picture book or the Bearhawk CD, you may have noticed that the bottom stringers stop short of being attached to anything at the rear end. The last several inches are just hanging out there unsupported. Why do you s'pose that is? You could propose several ideas, such as the difficulty of finding something to attach them to. Actually, the answer is much simpler... The stringer material comes in 12 foot lengths. The bottom stringer is 12 feet long. That is, using the full length of the stringer material, that's just how far it reaches. So much for tonight's Bearhawk trivia... Russ Erb +++ #12206 From: pfflyerz@c... Subject: Re: Bottom stringers stop short? As a side note along the same lines, you will notice in the picture book that the bottom stringers, at the back, are tapered. I tapered mine like the picture, but initially installed them with the taper leading up to the tail. After further review of the photo, I flipped them over to match the picture so the taper runs down. After covering, I decided that the first way was best as that would have allowed the fabric to make a smooth transition to the tail. The way mine is installed matched the photo, but it creates a very severe transition to the fabric, so much so that I put extra reinforcing tape over the ends of the stringer because I was afraid the stringer would puncture the fabric after shrinking. I would be willing to bet that Bob turned his around after that picture was taken, as there is no need to even make a taper as installed in the picture. Pat Fagan #232 Pearblossom, CA +++ #12215 From: Russ and Penny Erb Subject: Ground Handling Handles Way back when The Bob and Mike went to Alaska, they discovered that the Bearhawk needed some handles at the rear of the fuselage to drag the fuselage around on the ground. When tilted down appropriately, they also sit nicely on a sawhorse for tail wheel maintenance. Such handles were created on Proto II, but no plans were ever created. Shouldn't be a big deal, since the design isn't real critical. Here's what I did: I used T7 tube (5/8 x .035) for the handles. Why? It was the largest diameter/thinnest wall tube I had that would fit into my 1/2" EMT conduit bender (EMT is measured by inside diameter, 4130 is measured by outside diameter. 1/2" EMT is roughly 11/16" outside diameter). The conduit bender gives good support to the tube so that you can bend it over a fairly tight radius (about 4-1/2 inches) without collapsing the tube, which was better than I could say for the tubing bender I used for the tail surfaces. I used the conduit bender to bend the T7 tube through about 90 degrees (basically as far as you can bend it in one operation). I then trimmed it so that the maximum gap between the longeron and the inside of the handle was 2-1/8 inches (Why? It just looked about right). I attached it to the rear longeron with the aft end of the handle 1 inch forward of the attach point for the forward horizontal tail strut. The handle was rotated down until the top side of the lowest part of the tube (highest part if the fuselage is upside down) was even with the lower stringers. That puts the bottom of the handles 5/8 inch below the stringers. There's nothing magic about these numbers (unless you want your Bearhawk to match #164), but hopefully this will give you some ideas to start from, or at least more than I started with. Russ Erb +++ #12216 From: "Bruce A. Frank" Subject: Re: Ground Handling Handles After manhandling many taildraggers ranging from really heavy SkyBolts to J-3s and a Miniplane the most comfortable angle, to me, of a loop handle, like Russ described, was one that stuck straight out the side parallel to the ground (since the plane is sitting tail down it is not actually parallel to the ground....hmmm...parallel to the horizontal stabilizer). To reduce wear and tear on the vertical and horizontal stabs (where else are you going to grab it) a "D" handle off the lower longeron is an absolute necessity. I actually think they should be installed on both sides. Another place that is somewhat common on aircraft with a fixed horizontal stab with brace wires, unlike Piper jackscrew trimmed type, is a "D" handle ahead of or behind the leading edge of the horizontal stab (your hand fits through a hole behind the leading edge). I don't know the impact on drag of any of these three types. Bruce A. Frank +++ #12218 From: "Ellis, Carl" Subject: RE: Ground Handling Handles Angling the handle down for saw horses is a good idea. The down angle is a bit awkward but that is easily remedied by keeping a length of 3/8" (??) inch soft rope tied in a loop with a piece of PVC pipe slipped on before tying the knot. Slip the loop through the fuselage bracket, then the piece of PVC through that loop - the PVC pipe serves as a grip for your hand. Now you can easily lift the tail using your legs rather than your back and legs. I also use a tailwheel tow bar for my Taylorcraft F-19 with a Scott 3200 tail wheel. That long lever arm really make light work of an awkward job - especially since there is a slope up to my hangar door. The tow bar breaks down, is light, and could easily fit into a storage compartment. - Carl - +++ #12219 From: "Tim Anderson" Subject: Re: Ground Handling Handles If I recall correctly, Bob has his "D" on the bottom, ahead the hor stab strut. There are two scenarios...putting on the top longeron is nice for simple dragging the tail around...but one on the bottom longeron is needed for lifting the tail (more then a few inches). I know all about this because I have cursed my kitfox for not having a handle on the bottom. If I recall, C-180/5's have a retractable tube in the fuselage side. A bit alloborate for what we need. Tim Anderson +++ #12220 From: Tony Dean Subject: Re: Ground Handling Handles Hmmm..... A retractable tube may be overkill but what about a folding handle? This could fold against the aircraft with a small faring or not (simply leave a tube open at both ends). By folding back against the fuselage it would always have air presure to keep it in place. A simple bracket welded to the fuselage could protrude through the fabric and one bolt or a couple of rivets would attach the tube. Positive stops of some sort would be a good idea so it does not fold up accidentally when moving the aircraft. td +++ #12221 From: "Ellis, Carl" Subject: RE: Ground Handling Handles Bruce's comment about having the handles on both sides is a good one. I invariably walk to the wrong side. My Tcraft has the handle on the right side but I almost always want it to be on the left. - Carl - +++ #12223 From: Budd Davisson Subject: Re: Ground Handling Handles FYI, we put handles on both sides of the BH kits. bd +++ #12224 From: "Tony Snow" Subject: RE: Ground Handling Handles Retractable? Folding? What? Just keep it simple..... Weld that sucker on and be done. Tony (simple doesn't need repairs as often) Snow +++ #12225 From: Art Womack Subject: RE: Ground Handling Handles Amen on the simple Tony! Don't be afraid to make them big enough for both hands, you may wish you had if you ever have to horse your BH around in the snow. +++ #12227 From: Russ and Penny Erb Subject: RE: Ground Handling Handles Regarding the previously mentioned Cessna 180 handles that slide out: 1. On a friends 180, numerous times we have gotten out to find the handles sticking out. Kind of defeats the drag reducing idea of hiding them. Granted, welded handles create drag all of the time, but at least is stays the same. 2. While they are fine for moving the airplane around on the ground, just looking at them I wouldn't trust them to lift the tail of the airplane with them or support the tail using them. Not a problem with the welded tubes. Russ Erb +++ #12228 From: charles.k.scott@d... Subject: Re: Digest Number 957 > Hmmm..... > A retractable tube may be overkill but what about a folding handle? The Waco UPF-7 I occasionally deal with has a retractible tube that is spring loaded and slides out of the fuselage just in front of the horizontal stabilizer for ground handling. There's one for each side. Corky Scott +++ #12229 From: Ken Beanlands Subject: RE: Ground Handling Handles Oddly enough, our 1975 C-180 does not have the handles. I wonder if it was an option? Maybe it was not suppled with the float kit for some reason. However, we do have a very convenient handle in the tail for float operations It sticks strait out the rear of the plane and has a nice chrome handle on the end. It's more than strong enough to horse the plane around and to drag it up on the beach with. I think it can even be used to store a tailwheel ;-) Ken Beanlands B.Eng (Aerospace) +++ #12231 From: Russ and Penny Erb Subject: RE: Ground Handling Handles Hmmm...my friends 1977 C-180 has the float kit and the handles. Russ Erb +++ #12864 From: Russ and Penny Erb Subject: RE: two-place, speed, etc > On a 500 mile trip the difference of time enroute between cruising > 160 mph (BH speeds) and 180 mph is 21 minutes. If you up the cruise > speed to 200 mph, you save 37 minutes over the BH. Big deal! I agree with budd completely, especially when the path taken to more speed is through a bigger engine that sucks fuel down faster (and actually reduces range). On the other hand, I'm sure budd will agree with me that after building your Bearhawk, it's well worth the effort to fair in all of the non-aerodynamically shaped bits, whether your goal be to fly faster on the same power, or fly the same speed on less power (and less fuel burn). Russ Erb +++ #12868 From: Budd Davisson Subject: Re: two-place, speed, etc Along Russ's free-speed-through-aerodynamic-clean-ups: I'll go out on a limb and virtually guarantee that there is an easy 10 mph, probably more like 15mph that can be gotten out out of the airplane with the following simple changes, some of which wouldn't be done on a bush bird: -reflex flaps 5 mph -fair shock struts 3 mph -wheel pants (down, Pat!) 4 mph -brake/axle fairing 3 mph I think most will agree that these are conservative estimates but they give us an airplane that will cruise 165-170 mph TAS on a 540 and 23/23 power (60% or so) bd +++ #12923 From: "bearhawk232" Subject: weight and balance We weighed #232 yesterday, and though I never expected it to weigh as little as Bob's, it came out heavier than I had hoped. Proto 2 weighed in at 1270 and #232 came in at 1490. Where did all that weight come from? Mine has dual brakes, boarding steps (and related structure) on both sides, lots of fresh air ventilation (front and back) some sound proofing (though less than I had planned to install) skylight (and related structure) nut plates on everything (no PK screws) and finally, a lot of freakin' paint. I primed everything and, being a car painter, laid the final coats on heavier than need be. I even had to repaint the fuselage because I wasn't happy with the quality of the first job. I suspect most of the wieght gain came from paint. I had to add almost 5 lbs of lead to each aileron, after paint, to rebalance them. The elevators needed more weight as well, but not as much. My prop is 25 lbs heavier than Proto 2's, yet my battery is still able to sit behind the baggage compartment, so that weight is being canceled out somewhere. On a side note, there has been some discussion lately about the fit of the rear cargo and clearance when open. I have a few other thoughts to keep in mind. The front doors give the same problem due to the curve of the fuselage aft of the boot cowl. It isn't readily apparent when fitting the door hinges, but the sheet metal on the front of the door need to be trimmed in an arc to clear the front sheet metal. The door skin on the pilot's side of 232 covers the gap nicely, but the co-pilot's door leaves a hair line crack when the door is closed. Also, I found the bolts that fit so nicely in the hinges without skins would no longer turn for tightening after skinning. I used clevis pins on the rear cargo door as it was easier than trying to put on a nut. That's all I've got, hope to run the engine for the first time next week. Pat Fagan +++ #12924 From: Budd Davisson Subject: Re:paint and weight I'd suspect the paint too. When we finished rebuilding my Pitts last month it was 83 pounds lighter than when we started. The only difference is 12 pounds in the starter and we used much less paint, 3 quarts for the entire airplane, versus the 4 gallons used last time. The difference in how it flies is noticeable but you'd be hard pressed to see any difference at all in the finish. Finish may look good, but it always reduces useful load. bd +++ #12932 From: bearhwk272@a... Subject: Re: weight and balance Amazing how the weight creeps in huh? I bet that most of the weight is not in the paint. Remember Proto II was also painted, your extra paint is only incremental not a zero sum gain. Now that you are not building, grab a spreadsheet and just reflect on all the items, list em and add them. The stuff you mentioned plus, backseat,transponder, radio, GPS, prop spinner and backing plate complete electrical system, wire, fuses breakers, lights, strobes, panel lighting, upholstery on seats, patroller doors, heater, intercom, stainless steel exhhaust, additional flight and engine instruments. Considering all the items that you have crammed in above you should find that your nice paint is well worth the weight. The added capability that you have is pretty functional too. How would you like to do a night flight from Crystal to SMO or SBA in Proto II? All in all I think that you will find that you did a pretty good job of keeping the weight under control. Most things we want / need weigh something. Kevin +++ #12940 From: Russ and Penny Erb Subject: Window Frames According to the April 98 Bear-Tracks, the aluminum sheeting framing the front windows at the bottom consists of two pieces riveted together and then bolted on either side of the window. On the two sides and top, the aluminum sheets are just bolted on either side of the window sheet. Has anyone identified a reason for riveting the two sheets together at the bottom instead of just bolting them together through the window? Russ Erb +++ #12959 From: "piperthorp" Subject: Re: Window Frames I have not built the windows yet because I'm waiting to match the bottom of the window trim line to the windshield hold dowm strip.I believe that's the reason Bob shows the plexiglas spaced away from the frame so much. I think it looks best if the line from the bottom windshield hold down strip, the bottom of the window, and the bottom of the D window flow on the same line. In a related question are you going to use the 6-32 screws Bob shows? I don't think there will be much holding with a 6-32 screw in a .032 tube. We just finished a Maule swing out window conversion where all the attachments were with pop rivets. Piper often used #6 PK screws which will hold if not removed many times. Bill Cox #303 +++ #12962 From: Russ and Penny Erb Subject: RE: Re: Window Frames THAT'S what I was missing! Makes perfect sense now! That's also something for me to consider when placing the rear windows. As for the 6-32 screws, I wasn't too thrilled with the idea of a 1/2 thread grip. That's why I stocked up on a whole mess of Rivnuts. All of the screws will be in Rivnuts. Since Rivnuts are not self-locking, I'll be using a goodly amount of Loc-Tite. Russ Erb +++ #12980 From: Russ and Penny Erb Subject: Locking up your Bearhawk Here's some ideas for you on how to secure your Bearhawk in the light, simple, Bob Barrows would probably approve way. I've thought about this for several years, and think I've finally come up with a good, simple, workable system. But first, the caveats: Like the locks on most production aircraft, what I'm suggesting here won't keep the determined criminal from stealing your avionics. For that, a simple knife through the fabric will allow access. As a friend of mine said many years ago, these locks keep the honest people out. If you're at a fly-in and don't want grimy kids opening your doors and stuffing their heads in your airplane, these will work. For the forward doors and windows, we just need to keep the window from opening, since the door handle is only on the inside. For this, I propose to weld a tube vertically between the door and window near the back end. To keep it straight, weld one tube to both, then cut the middle out to separate the door and window. The lock is a simple 3/16" bolt (or a AN42 eye bolt) slipped down through the two tubes. A similar tube welded to the vertical tube right behind the door and window will provide a convenient location to store the lock bolt while you're flying. If you use the AN42 eye bolt, you can tie a cord through the eye and to the airframe so that you won't lose the bolt. The rear cargo door is already set up such that it can't be opened until the forward cargo door is opened (I used to think this was a way-cool Bob Barrows invention until I saw an almost identical setup on a Maule). To lock the forward cargo door, you'll need a small keyed barrel lock where the key turns a metal tab at the other end. Make a small bracket for the lock above or below the door bolt. The metal tab will rotate behind the frame of the rear cargo door to lock the front door. These locks can be purchased at your local lock shop. Typically they're used for locking things like cabinet doors. Therefore, to lock up your Bearhawk, close the front doors and windows. Open the front cargo door, reach in, and place the lock bolts in the tubes on both doors and windows. Close both cargo doors, then use the key to lock the cargo doors. If this sounds vaguely familiar, there's a reason for that. The idea was based on the Cessna 180 system, where you close the right door fully (can't be opened from outside), then feed your body into the baggage door and close the left door fully. Then you squirm out and lock the baggage door with a key. Someday I'll stop typing and get back to actually building. Then again, I might be behind Pat Fagan, but I'm still way ahead of Planter Bob... ...first I need to mod my rear window frames...based on this morning's discussion, they're too wide at the front to line up with the window and windshield fairing. Russ Erb +++ #12991 From: "ken wardstrom" Subject: fairing boots We were wondering if there is a commercially available set of fairing boots for the wing struts and landing gear, or something from another plane, or is it scratch build only. Any input greatly appreciated. - ken +++ #12999 From: Pat Fagan Subject: Re: Locking up your Bearhawk Russ has the right idea on locking up the Bearhawk. I put a keyed lock cylinder on the cargo door and it works great. I believe I have come up with a simpler solution for locking the front doors though. I have a bracket, welded at the junction of the tube the runs below the insturment panel and the door pillar, that holds a fresh air vent. In an unobstrusive area of this bracket I drilled a #30 hole. From a piece of 1/16 steel rod, I made a lock rod with a 90 degree bend on one end and a loop on the other. To lock the door, I put the 90 end in the hole, then drop the loop over the U for the window latch. That's it, totally secure. Even without the bracket, this method could be utilized by welding a small gusset at the tube junction. Pat Fagan +++ #13000 From: Russ and Penny Erb Subject: RE: Locking up your Bearhawk Pat's solution sounds similar to another idea I had earlier. I changed to what I described because I thought it would easier to reach a locking device at the rear of the window than at the front of the window, especially when reaching in from the cargo door. Pat--I suspect it's not an issue, but I would encourage you to wait until at least 1 Jan 03 to fly your Bearhawk. EAA is giving out special awards and recognition to homebuilts that have their first flight in 2003, the 100th year of powered flight. Russ Erb +++ #13001 From: Budd Davisson Subject: Re: Locking up your Bearhawk I know this is a little crude (in keeping with the author) but what's wrong with having a small tab somewhere on the airframe sticking through a slot in one door frame and putting a small padlock on it? bd +++ #13004 From: mprather@s... Subject: Re: Locking up your Bearhawk Yes, I think I would like to have a seperate lock on at least one of the front doors. If you have to lock the plane through the cargo door, what's the plan when you have a bunch of gear in the airplane? Matt Prather +++ #13005 From: "Bruce A. Frank" Subject: RE: Locking up your Bearhawk This is an interesting thread. Let me add a couple of cents worth. Airplanes are very vulnerable to break-ins and theft of instruments and radios. Tube and fabric craft can offer virtually no security from an even slightly determined thief. The most ingenious setup I have ever seen did nothing out of the ordinary to the access doors, but the panel treatment eliminated even an inkling of a reason for breaking in. The builder had a very complete radio stack with high dollar moving map GPS with all the bells and whistles. He installed a cover fabricated from aluminum diamond plate (it was only 16 gauge but diamond plate "looks" thick and impenetrable). The bottom edge of the shield grabbed the cross tube at the bottom of the instrument panel and hinged up to completely eliminate view of anything on the panel. At the top of the shield was a slot through which a heavy loop extended through in which the builder installed a very heavy cylindrical keyed padlock that was clearly stamped "Hardened" visible through the door window. The loop through which the lock passed was protected by structure that prevented access with a hack saw or bolt cutter ( the builder told me that the loop was actually a hardened piece also, so un-cuttable by most hardware store methods). His object was to prevent knowledge of what was desirable in the plane and to slow a thief down enough that fear of detection would be a deterrent. When not in use the shield fit under the front seats support structure. The shield weighed 4 lbs; the lock weighed 1.25 lbs, but he had never even had a break-in when vandals and thieves hit planes all around him. Bruce A. Frank +++ #13007 From: Tony Dean Subject: Re: Locking up your Bearhawk This is getting good. I have seen one deterance system of just a steel bar that locks across the front of the radio stack. http://www.mustangaero.com/images/Album/Mustang%20II/Instrument%20Panel/Instruments3.jpg Years ago I saw an interview with someone doing time for his tieving ways. When asked about what to do to protect the house, he said double deadbolt was very effective. He claimed he could always get in but you have to be able to get out carrying the goods. He claimed if one house is too hard to deal with, they just move on to the next one. I like the idea of the cover because it removes the items from sight. A guy in our EAA chapter does not have much in the way of panel mount instruments. His Nav/Com and GPS are both handhelds. That way he can just "take them with" when he leaves the plane. td +++ #13008 From: Ken Beanlands Subject: Re: Locking up your Bearhawk That's what the C-180 uses. There is a keyed lock on the pilot's door and you lock the passenger side door from inside first. The cargo door has it's own keyed lock that matches the front. Simple. but effective! Ken Beanlands B.Eng (Aerospace) +++ #13028 From: "collinc2002" Subject: door lock system With the recent discussion of how to lock up our Bearhawk, I thought I might as well share what I am doing with mine. I have posted three new pictures in the "photos" section. Look under "Collin's Bearhawk". Two pictures of the lock system (inside and outside view) as well as a current picture of the fuselage as of this date. Collin Campbell #370 +++ $Id: 2.3.6-Fuse-Other,v 1.10 2003/05/22 03:25:34 bentonh Exp $