Date: Thu, 2 Jan 1997 00:51:03 -0500 From: INFINITY Aerospace <72124.347@compuserve.com> Subject: COZY: Shear Web Hi to All, >John Epplin wrote:< >Have one question you might be able to answer. The drawing for BL37 has a comment "shear web cut accurately". This line is not 90 deg to the water line on my drawing. I think it should be and seem to remember some comment like that in the book someplace.< You are correct. The shear web cut line should be perpendicular (90 degrees) to the waterline. See Wing Chapter 19, page 2, bottom right, concerning cutting the wing shear web. When you mate page M-3 to page M-24, the shear web is perpendicular to the waterline. While I'm talking about wings again, note the joggle on the bottom leading edge of the canard. Do the same thing to the bottom leading edge of the wing so when the top and bottom wing skins are overlapped, you won't have a bump to contend with. Infinity's Forever, EAA Member EAA Technical Counselor JD EAA Flight Advisor AOPA Member Test Pilot James D. Newman, President LCDR F-14 USNR INFINITY Aerospace Mailing Address: P. O. Box 12275 El Cajon, CA 92022 Shipping Address: 1750 Joe Crosson Drive, D-2 El Cajon, CA 92020 (619) 448-5103 PH & FAX 72124.347@compuserve.com OR INFINITY_Aerospace@compuserve.com Home Page http://ourworld.compuserve.com/homepages/INFINITY_Aerospace Date: Thu, 2 Jan 1997 00:51:09 -0500 From: INFINITY Aerospace <72124.347@compuserve.com> Subject: COZY: Wing Airfoil Jig Trailing Edge Mis-Alignment - Not Hi to All, >John Epplin wrote:< >Also there has been some discussion concerning the jig trailing edges not aligning up in a straight line. Any ideas?< Yes, Phil Johnson also had some concerns he posted on the 4th and 5th of Dec. '96 about the apparent discrepancy of wing wash-in and wash-out between the wing foam templates and the wing foam jigs from BL 67.5 to the wing tip. The trailing edge of the wing foam and the trailing edge of the wing jig templates are a straight line from BL 67.5 to the wing tip. The confusion I think some are having is that the 'S' curved line at the trailing edge of the jig template airfoil in the jig template plans that WL 17.4 reference line seems to be pointing to is not an arrow or line pointing to each trailing edge of the wing jig airfoil templates, but is a physical cut line reference for when the builder cuts out the wing airfoil jig templates and separates them into top and bottom halves. See Wing Chapter 19, page 1, top left, for details of the jig templates and that top and bottom half cut line. If memory serves, this was a point of confusion and concern 13+ years ago in the Long-EZ plans. As to taking the twist out of the trailing edge from BL 67.5 to the cowling, that's up to the builder. Jeff Russell can probably address this - it is nice to have a straight trailing edge the entire length of the wing. I mentioned doing this to Shirl Dickey in Nov. '85 when I visited him as to why the wing swept up to the cowling - so the Vari-EZE cowling could be used for the Long-EZ. Infinity's Forever, EAA Member EAA Technical Counselor JD EAA Flight Advisor AOPA Member Test Pilot James D. Newman, President LCDR F-14 USNR INFINITY Aerospace Mailing Address: P. O. Box 12275 El Cajon, CA 92022 Shipping Address: 1750 Joe Crosson Drive, D-2 El Cajon, CA 92020 (619) 448-5103 PH & FAX 72124.347@compuserve.com OR INFINITY_Aerospace@compuserve.com Home Page http://ourworld.compuserve.com/homepages/INFINITY_Aerospace Date: Thu, 2 Jan 1997 15:32:03 -0500 From: INFINITY Aerospace <72124.347@compuserve.com> Subject: COZY: Cowling Hi to All, >John Epplin wrote (Hi John):< >Now, about inboard, if I make a straight trailing edge, I intend to purchase my cowling, Will it fit? I need a finished A/C to look at to visualize this.< Depends on who you buy the cowling from. If Jeff Russell has straightened the trailing edge all the way to the cowling, he is probably the only one who will have a cowling to match your wing, assuming Jeff does sell cowlings (I think he does - take 'er away Jeff), and assuming you do your wing trailing edge the way Jeff did, of which I assume he did it similar to what was discussed in our posts. HTH. Infinity's Forever, JD From: jan-erik.synnerman@lf.se Date: Tue, 7 Jan 1997 11:15:17 +0100 Subject: COZY: Wing Position Lights Hi everybody, I want to make flush wingtip position lights (red, green) on my Cozy III.=20 Like a Glas Air or a Lance Air. That makes it necessary to cut into the win= g=20 skin in front of the winglet leadig edge, lets say 3x3 inches. Is that=20 permissible, or will it weaken the structure to much? I don=B4t think it wi= ll,=20 but does anybody know for sure? Jan Erik Synnerman, Stockholm, Sweden From: Marc J. Zeitlin Subject: COZY: Wing Position Lights (fwd) Date: Tue, 7 Jan 97 14:20:48 EST Jan Erik Synnerman wrote; >I want to make flush wingtip position lights (red, green) on my Cozy III. >Like a Glas Air or a Lance Air. That makes it necessary to cut into the wing >skin in front of the winglet leadig edge, lets say 3x3 inches. Is that >permissible, or will it weaken the structure to much? I don't think it will, >but does anybody know for sure? I certainly don't know for sure (ask Nat), but I'd say that as long as you don't cut into the UNI and BID cloth that attaches the winglet to the wing, you should be fine. The wingtip has almost no stress on it, and the thickness of the skin is determined more for dent resistance than for load carrying capacity. Losing a 3x3 inch patch of unloaded skin _shouldn't_ make any difference. My $0.02. -- Marc J. Zeitlin Email: marcz@an.hp.com From: Epplin_John_A@hpmail1.90.deere.com Date: Tue, 7 Jan 97 14:05:29 -0600 Subject: COZY: Wing Position Lights Jan Erik Synnerman writes: > Hi everybody, > I want to make flush wing tip position lights (red, green) on my Cozy III. I don't know your regulations, but we are required certain angle coverage for approved lighting. If the lamps were flush, you may need transparent skins to ensure proper angle coverage. With Epoxy-glass skins this may work out quite well if you remove all the foam from the area required. I am about to start laying up wings and this interests me. Let us know what you come up with. John Epplin, Mk4 #467 Date: Wed, 08 Jan 1997 08:30:02 -0800 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: wing position lights Hi to all, regarding the positioning of the wing tip lights, the required visibility angles, etc. are internationally agreed and can be found in the ICAO, Jeppensen, and your AIP's. Hopefully, mine will be fitted flush, a la landing brake, using the cut out piece as a mould for perspex. Anyway, i'm nowhere near this yet, but keep writing, I'll catch your info from the archives. thanx all. chris #219 in ch 08 Date: Wed, 8 Jan 1997 20:57:54 -0500 From: INFINITY Aerospace <72124.347@compuserve.com> Subject: COZY: Wing Position Lights (fwd) Hi to All, >Marc Zeitlin wrote:< >I certainly don't know for sure (ask Nat), but I'd say that as long as you don't cut into the UNI and BID cloth that attaches the winglet to the wing, you should be fine. The wingtip has almost no stress on it, and the thickness of the skin is determined more for dent resistance than for load carrying capacity. Losing a 3x3 inch patch of unloaded skin _shouldn't_ make any difference.< Correct. The navs and strobes could be done. The tail light would have to be on the top and bottom of the cowling, or fashion a tail light into the top tip of the winglet, or the bottom winglet trailing edge. >John Epplin wrote:< >I don't know your regulations, but we are required certain angle coverage for approved lighting. If the lamps were flush, you may need transparent skins to ensure proper angle coverage. With Epoxy-glass skins this may work out quite well if you remove all the foam from the area required. I am about to start laying up wings and this interests me. Let us know what you come up with.< It can be done. Or, something easier to do, Long-EZ driver Dave Lind (619) 755-6117 makes a really slick airfoil shaped lens that covers the entire popular nav-strobe-tail light combination presently used. HTH. Infinity's Forever, JD From: Epplin_John_A@hpmail1.90.deere.com Date: Fri, 24 Jan 97 10:53:42 -0600 Subject: COZY: Wing jigs I finally got the laser cut templates finished. They were cut from 16 ga. mild steel, one each on size and one each .032 oversize. I used the oversize for the wire cutter then mounted the on size and used a long aluminum level with 36 grit paper glued to it to sand to the template. The procedure worked very well, the cores look perfect. Next step is to cut the leading edge off and mount the rest for the shear web lay-up. QUESTION: what is the latest procedure concerning the T.E. bend at BL67.5 which I understand is in order to mate something to the cowling? I don't have a finished bird in the immediate area to look at and don't quite understand what is going on here. HELP! John Epplin #467 Date: Fri, 24 Jan 1997 15:01:12 -0500 (EST) From: DFinn7971@aol.com Subject: Re: COZY: Wing jigs In a message dated 97-01-24 13:24:26 EST, Epplin_John_A@hpmail1.90.deere.com writes: << what is the latest procedure concerning the T.E. bend at BL67.5 which I understand is in order to mate something to the cowling? I don't have a finished bird in the immediate area to look at and don't quite understand what is going on here. >> John, The bend will appear naturally just by setting the wing jigs per the plans. I think it would take some effort to avoid putting it in. I followed the directions carefully and completed the first wing. When I sighted down the leading edge it was straight as an arrow. I paniced when I sighted the trailing edge and found a noticible bend. I immediately called Nat who told me it was supposed to be there. As you suggest it is there to allow the wing to smoothly join with the cowling. I believe that this is a carry over from the Long-eze (I did check this out on a friends Long-eze and found the bend in his wing). It seems to me that Jeff Russell has taken it out on the Aerocanard by redoing the cowling. Not being an aero engineer I can't say that it serves no aerodynamic purpose but I believe that it is strictly related to blending the wing into the cowling on the Long. Dick Finn Cozy Mark IV #46 DFINN7971@AOL.COM Date: Tue, 28 Jan 1997 13:29:39 -0500 (EST) From: Westlande@aol.com Subject: COZY: Wingroot Bearing? As we have discussed before, the phenolic block for the wingroot bearing has better alternatives. I may have found a self-aligning spherical bearing that may be a good substitute. It uses UHMW for the sphere and weighs about 5 oz. according to the catalog (Graingers). To check it out, go to www.grainger.com and browse the catalog by part number (1F574). They are $7.06 each. Can anyone think of why these would not work? Eric Westland by SERV05.SLAC.STANFORD.EDU (PMDF V5.1-4 #16063) with SMTP id <01IEQVO27V0W002ESM@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Tue, 28 Jan 1997 12:25:13 PST Date: Tue, 28 Jan 1997 12:25:10 -0800 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Wingroot Bearing? >As we have discussed before, the phenolic block for the wingroot bearing has >better alternatives. I may have found a self-aligning spherical bearing that >may be a good substitute. It uses UHMW for the sphere and weighs about 5 oz. >according to the catalog (Graingers). To check it out, go to >www.grainger.com and browse the catalog by part number (1F574). They are >$7.06 each. Can anyone think of why these would not work? > >Eric Westland Eric, I looked at the catalog entry, and this seems extremely similar to the bearing I have here, on my desk. I bought it years ago, and don't remember where I got it (a group of us ganged up on this one). It is made by Pobco, Worcester, Mass. It is stainless, with the bearing in the center made of teflon. There is such a low load on it, that I wasn't too concerned about "creep" of the teflon. It is very low friction, and at least somewhat fire-resistant. I have some that are identical, but with the insert made of an exotic, oil-impregnated wood (of all things!) for the torque-tube bearings inside the cockpit. It works fantastic, and if I can believe the company's hype about the durability of this special wood, it should outlast several phenolic bearings, in this application. I don't know what UHMW is. Do you? It is the only thing I can think of that could be a problem with this. I am in the process of figuring out how to best hold this bearing in the proper location, making sure that the "sphere" is positively captured, so it can't "pop out" of its socket, under any circumstances. Howard Rogers A&P 2005148 Date: Tue, 28 Jan 1997 18:49:21 -0500 From: Rick Roberts <102503.1561@compuserve.com> Subject: Re: COZY: Wingroot Bearing? UHMW = ultra high molecular weight. Usually implies extremely long polymer chains and is used with polyethylene. Rick Roberts Date: Tue, 28 Jan 1997 18:53:26 -0500 From: INFINITY Aerospace <72124.347@compuserve.com> Subject: Re: COZY: Wingroot Bearing? Hi Howard and All, >I am in the process of figuring out how to best hold this bearing in the proper location, making sure that the "sphere" is positively captured, so it can't "pop out" of its socket, under any circumstances.< We make a housing to hold the SS spherical bearing for the canard aileron root, firewall and in the cockpit. The housing, spherical bearing and hardware to mount it is $40 each, plus S & H. The bearings are from Aurora Bearing, the same place Aircraft Spruce buys them from, but I charge a lot less. Infinity's Forever, EAA Member EAA Technical Counselor JD EAA Flight Advisor AOPA Member Test Pilot James D. Newman, President LCDR F-14 USNR INFINITY Aerospace Mailing Address: P. O. Box 12275 El Cajon, CA 92022 Shipping Address: 1750 Joe Crosson Drive, D-2 El Cajon, CA 92020 (619) 448-5103 PH & FAX 72124.347@CompuServe.com OR INFINITY_Aerospace@CompuServe.com Checkout our Stick Grips, Retractable Main Landing Gear and the Infinity 1 Home Page http://Ourworld.CompuServe.com/Homepages/INFINITY_Aerospace Date: Tue, 28 Jan 1997 19:26:32 -0500 From: Paul Burkhardt Subject: COZY: RE: WING ROOT BEARING I am in the process of figuring out how to best hold this bearing in the proper location, making sure that the "sphere" is positively captured, so it can't "pop out" of its socket, under any circumstances. I had a local machinist use a lathe to cut the diameter perfect in an aluminium plate. He then pressed in the bearing. My concern for the "popping out" of the bearing was aswaged somewhat by the fact that on the rear side I had installed a plate( under the fiberglass in the wing root area which was matched drilled to the aluminium plate which held the bearing)it has an opening just large enough for the torque tube. The bell crank it so close that it really cant "fall out" The aluminium plate was 1/2 in thick as is the bearing. I wished I could have found a lighter bearing at the time as this seems somewhat super heavy duty. The bearing is stainless steel with a stainless steel ball. Paul Burkhardt Date: Wed, 29 Jan 1997 01:54:54 -0500 (EST) From: Westlande@aol.com Subject: Re: RE: COZY: Wingroot Bearing? In a message dated 1/28/97 7:53:53 PM, you wrote: >Eric, > >I went over to a local Grainger store and looked at their bearings when I was doing >my wings. I'm not sure if the ones I looked at where the >exact number you mentioned although the picture on the web catalog looks exactly >the same. I was real excited when I found them in the >catalog but was extremely disappointed when I saw them. In one word they are "gross" >bearings for the application you are looking for. They >are too wide, very heavy, and are only self aligning until you tighten the mounting >bolts. Those bearings are made for large fan >applications where you slide them on the shaft (which aligns them) and then tighten >them down which makes them essentially rigid. Not really >what you want. That's probably why they are so cheap. Now that I have looked at the picture again, I think I see how the sphere is captured and how they might tighten up after mounting. You're probably very correct and have saved me a trip - thanks. I hope you don't mind, but since I "re-started this", I feel I should share this observation with the others to possibly save them a trip as well. > >I used the bearings described in a past issue of the Central States Newsletter >and which I believe are discussed in the Cozy archives. They >where perfect for the application but expensive, $20.00. A friend of mine found >the same part number in Canada for less than $10.00. If you >like I could dig out the part number, don't have it here with me now. > >Regards >Ray Volk >rvolk@space.honeywell.com > > I am going to look at the bearing mentioned in the archives tomorrow. I had some sent up from Portland. If you can get the part number you used, that would be great as there may be some differences. Thanks again, Eric Date: Thu, 30 Jan 1997 03:49:27 -0500 (EST) From: Westlande@aol.com Subject: COZY: Wing Root Bearing, con't... Just to update you all, I went to look at the COM-10 spherical bearing that was mentioned in the archives. While it is a well made bearing, it does not have flanges installed, so a housing would have to be made to mount it. But even if I was willing to do that, the control piece I bought from Brock is 0.003" oversize, so it won't fit in this bearing. I'm going to the Delrin or UHMW like some of you folks did - time to get this bird in the air! Question: Where can you get 1/4" stock? Wicks and ACS don't carry it. Is there a mail order source? Anyone got some laying around that they want to sell or want to go in on some? Eric Westland Date: Thu, 30 Jan 1997 07:58:19 -0500 From: william l kleb Organization: NASA Langley Research Center Subject: Re: COZY: Wing Root Bearing, con't... Westlande@aol.com wrote: > > ... I'm going to the Delrin or UHMW ... > > Question: Where can you get 1/4" stock? check your yellow pages under "Plastics". for example, in my local area we have three suppliers. i have been to two and the both have a mind-boggling array of materials, sizes, etc. they both had cut-off pieces they were willing to part with for $5 -> $20. -- bil From: "Volk, Ray" Subject: RE: COZY: Wing Root Bearing, con't... Date: Thu, 30 Jan 1997 16:39:39 -0500 ---------- F Eric wrote- >>Just to update you all, I went to look at the COM-10 spherical bearing that was mentioned in the archives. While it is a well made bearing, it does not have flanges installed, so a housing would have to be made to mount it. But even if I was willing to do that, the control piece I bought from Brock is 0.003" oversize, so it won't fit in this bearing. >> Eric The bearing I used was a Torrington 7SF12. A typical installation is described in the Central States Newsletter issue # 8 which was the Fall of 1987, page 13. I did an adaptation of that installation, they used plywood microed into the foam to hold the nut plates for the aluminum housing to support the bearing. I used an aluminum plate and made the bearing support housing out of aluminum. My control piece from Brock was also too large for the bearing but about 20 minutes with some good sand paper on the inside of the bearing and it fit perfectly. I realize you are now taking a different course but if you are still interested I could fax you copies of the CSA approach and also what I did (2 pages total). Ray rvolk@space.honeywell.com From: Epplin_John_A@hpmail1.90.deere.com Date: Wed, 5 Feb 97 08:46:59 -0600 Subject: COZY: Wing attach bolt pockets Just glassed in the pockets in the wing for the outboard attach bolts. What provisions should I make for covering these after the A/C is finished? They will be outside the Prop arc so will not be supper critical. John Epplin Mk4 #467 Date: Wed, 05 Feb 1997 11:38:32 -0500 From: Mahan Subject: Re: COZY: Wing attach bolt pockets In Long-EZ plans, you just make oval covers out of .063 aluminum, paint them, and RTV them over the 4 holes. Fred in Florida Long-EZ N86LE Epplin_John_A@hpmail1.90.deere.com wrote: Just glassed in the pockets in the wing for the outboard attach bolts. What provisions should I make for covering these after the A/C is finished? They will be outside the Prop arc so will not be supper critical. John Epplin Mk4 #467 From: Marc J. Zeitlin Subject: COZY: Wing attach bolt pockets (fwd) Date: Wed, 5 Feb 97 17:39:03 EST John Epplin wrote: >Just glassed in the pockets in the wing for the outboard attach bolts. What >provisions should I make for covering these after the A/C is finished? I wasn't able to find anything about this in the plans. I've seen some covers such as Fred Mahan suggested, but I wasn't thrilled with them. I'm planning to make some 5 BID covers that sit on a 1/8" - 1/4" wide flox/epoxy shoulder that I installed 1/16" below the level of the wing surface around the periphery of the bolt access holes. I figure that I can get the slight curvature by laying up the cover next to the hole (over some box sealing tape), and will hold them down with a couple of screws into some nutplates installed somehow (I know, it's not completely thought out yet :-) ). I just didn't want a flat cover that was RTV'ed in place so that it would be difficult to remove easily. -- Marc J. Zeitlin Email: marcz@an.hp.com by SERV05.SLAC.STANFORD.EDU (PMDF V5.1-4 #16063) with SMTP id <01IF2ADQAZQ0002OF3@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Wed, 5 Feb 1997 16:24:46 PST Date: Wed, 05 Feb 1997 16:25:05 -0800 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Wing attach bolt pockets (fwd) >John Epplin wrote: > >>Just glassed in the pockets in the wing for the outboard attach bolts. What >>provisions should I make for covering these after the A/C is finished? > >I wasn't able to find anything about this in the plans. I've seen some >covers such as Fred Mahan suggested, but I wasn't thrilled with them. >I'm planning to make some 5 BID covers that sit on a 1/8" - 1/4" wide >flox/epoxy shoulder that I installed 1/16" below the level of the wing >surface around the periphery of the bolt access holes. I figure that I >can get the slight curvature by laying up the cover next to the hole >(over some box sealing tape), and will hold them down with a couple of >screws into some nutplates installed somehow (I know, it's not completely >thought out yet :-) ). > >I just didn't want a flat cover that was RTV'ed in place so that it would >be difficult to remove easily. > >-- >Marc J. Zeitlin Email: marcz@an.hp.com I have given this some thought, also, Marc. Rutan made a later plans change that called for a soda straw conduit between the upper and the lower pocket, plus a small drain hole in the lower cover. This came after some rusting wing-attatch hardware was found. Water can collect in the upper pocket pretty easily, either through leakage or condensation. I was thinking along the lines of a shoulder similar to your description. This would provide for positive location of both covers. Since a ventilation/drain hole already exists between the upper and lower pocket, why not simply tie the two covers together with a long flush-head screw? You could provide a single nutplate on the underside of the upper cover. I was planning to provide two drain-holes. One would drain in the nose-down parking position. The other would drain aft, in level flight attitude. What do you think? Howard Rogers A&P 2005248 From: Marc J. Zeitlin Subject: COZY: Wing attach bolt pockets/drain holes Date: Thu, 6 Feb 97 9:36:08 EST Howard Rogers wrote: >........... I was >thinking along the lines of a shoulder similar to your description. This >would provide for positive location of both covers. Yes, that was my purpose, as well as making it perfectly flush. >.......... Since a >ventilation/drain hole already exists between the upper and lower pocket, >why not simply tie the two covers together with a long flush-head screw? I like it. Stainless, since it's in the drain hole, and don't tighten the screw too tight. >You could provide a single nutplate on the underside of the upper cover. I >was planning to provide two drain-holes. One would drain in the nose-down >parking position. The other would drain aft, in level flight attitude. >What do you think? Sounds good. Just one question. In the nose down attitude, the water would collect in the spar recess - do you propose drilling a hole in the center of the shear web to allow draining? This would probably be OK, since there's little to no stress at the center of the web (although it couldn't hurt to put a few layers of BID around the hole area. -- Marc J. Zeitlin Email: marcz@an.hp.com by SERV05.SLAC.STANFORD.EDU (PMDF V5.1-4 #16063) with SMTP id <01IF36I8XWAI002UL8@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Thu, 6 Feb 1997 07:44:36 PST Date: Thu, 06 Feb 1997 07:44:56 -0800 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Wing attach bolt pockets/drain holes > >Sounds good. Just one question. In the nose down attitude, the water >would collect in the spar recess - do you propose drilling a hole in the >center of the shear web to allow draining? This would probably be OK, >since there's little to no stress at the center of the web (although it >couldn't hurt to put a few layers of BID around the hole area. > >-- >Marc J. Zeitlin Email: marcz@an.hp.com Well, like you, I hadn't totally thought out all of this, either. I was referring to two holes in or around the lower cover, but you're right. This wouldn't drain any water that collected in the upper pocket, while parked. I had also intended to seal at least the upper cover with RTV, using saran as a release, so that it is still easily removable, but also well-sealed. I'll have to go back and look at it some more, to see if it's possible to drill in such a way as to drain under all circumstances. Also, I really like your idea of laying up a curved BID cover. --Howard Rogers, 415-926-4052 hrogers@slac.stanford.edu From: Epplin_John_A@hpmail1.90.deere.com Date: Thu, 6 Feb 97 10:11:15 -0600 Subject: Re: COZY: Wing attach bolt pockets/drain holes > > > > >Sounds good. Just one question. In the nose down attitude, the water > >would collect in the spar recess - do you propose drilling a hole in the > >center of the shear web to allow draining? > >Marc J. Zeitlin > > Well, like you, I hadn't totally thought out all of this, either. I was > referring to two holes in or around the lower cover, but you're right. > This wouldn't drain any water that collected in the upper pocket, while > parked. I had also intended to seal at least the upper cover with RTV, > using saran as a release, so that it is still easily removable, but also > well-sealed. I'll have to go back and look at it some more, to see if it's > possible to drill in such a way as to drain under all circumstances. Also, > I really like your idea of laying up a curved BID cover. > > --Howard Rogers, 415-926-4052 It seems to me that you must drill through the lower cap strip, a no no, to drain in the nose down parked position. Also you would need a interconnect tube forward against the sheer web as well as one rearward. This would be OK but it would have to be installed before the AL parts and the sheer web. Too late for me. I think I will combine some of the ideas presented here and use a single interconnect tube with a screw passing through it from the bottom. I will make the covers by laying up BID over the adjacent wing surface over a release tape. I will glass a thin AL hat section to the upper cover to attach a plate nut to. A shoulder will have to be constructed to allow the covers to bottom out on. A little RTV and release could be used to form a gasket. A small drain hole can be drilled in the lower cover. This will not drain in the nose down parked position, but should drain in flight. I would suspect that the seal would not be gas tight which would be OK as a small air flow through both cavities in flight might be a good idea. Actually the sail cloth repair material would probably be more than adequate and only take a few minutes as opposed to hours for the above. Sounds better all the time. John Epplin From: DMDS%mimi@magic.itg.ti.com Date: Thu, 6 Feb 97 13:08:48 CST Subject: COZY: Chapter 19 Wing Spar/Layup question From: David de Sosa DMDS Subj: Chapter 19 Wing Spar/Layup question I have a friend who purchased a Cozy MkIV project from someone else who was kind enough to mention an inadvertant deviation from the plans possibly causing a concern about the interface between the top skin layup and the spar cap. Apparently, being dissatisfied with the trough remaining after completing the spar layup (both top and bottom of wings), the original owner filled in the remaining trough with micro flush to the foam surface before glassing over the top skin which is deviation from what the plans call out. Although this made for a smoother surface prior to finishing, there is now a concern as to whether the strength (longitudinally) of the wings has diminished. Is there a possibility of shearing along the micro/glass plane if the wings experience a lot of flexing over time? If this situation is not acceptable, can the wings be easily reworked, i.e. cut through top skin, remove micro, overlay ?? layers of top skin somehow without deforming the airfoil shape etc. or is he forced to start over from scratch? Any inputs would be much appreciated. David From: Marc J. Zeitlin Subject: COZY: Chapter 19 Wing Spar/Layup question (fwd) Date: Thu, 6 Feb 97 14:56:02 EST David de Sosa wrote: >...... the original owner filled in >the remaining trough with micro flush to the foam surface before glassing >over the top skin which is deviation from what the plans call out. AAARRRGGGHHH. The plans _specifically_ admonish you _NOT_ to do this!!! >.......... there is now >a concern as to whether the strength (longitudinally) of the wings has >diminished. Is there a possibility of shearing along the micro/glass plane >if the wings experience a lot of flexing over time? Or the first time you create lift. The micro is _NOT_ structural, but it's now being asked to carry the shear load between the skin and the spar cap. It can't do this. Do _NOT_ fly this wing as is. >If this situation is not acceptable, can the wings be easily reworked, i.e. >cut through top skin, remove micro, overlay ?? layers of top skin somehow >without deforming the airfoil shape etc. or is he forced to start over >from scratch? You could probably sand off the skin and micro that's over the spar cap along with ~2" - 4" of skin on either side of the cap. Then lay up new skin where you've got foam and spar cap, making sure to get at least 1" of overlap onto the rest of the skin. Then, following the instructions in the last chapter (finishing) micro _OVER_ the glass to fair in the airfoil shape. Thankfully the guy told your friend this - it could easily kill him. If I were your friend, I'd try to get an appreciable part of my money back from the original builder - who knows what else he did wrong? -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Thu, 06 Feb 1997 16:28:00 -0500 From: "Jeff S. Russell" Organization: AEROCAD INC. Subject: Re: COZY: Chapter 19 Wing Spar/Layup question (fwd) Marc J. Zeitlin wrote: > You could probably sand off the skin and micro that's over the spar cap > along with ~2" - 4" of skin on either side of the cap. Then lay up new > skin where you've got foam and spar cap, making sure to get at least 1" > of overlap onto the rest of the skin. I would have said the same, for that kind of fix. I know of at least two builders that have sanded off wing skins that I have rejected on my inspection. It can be re-glassed in total if the skins in total are not airworthy. -- AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/ call first for fax 910-961-2238 NEW E-mail: JRAEROCAD@yadtel.net NEW homepage address: http://www.binary.net/aerocad Date: Sun, 9 Feb 1997 10:39:13 +0200 From: edegov@aztec.co.za (ernie de goveia) Subject: COZY: Wing pockets Hi Folks All the talk of drilling through spar caps concerned me, so I looked up the original write up in newsletter #4 (was that a long time ago?). The purpose of the straw joining the wing pockets, and the hole in the bottom cover where for ventilation, to prevent condensation and subsequent corrosion. Not for drainage. This supposes that the top cover is adequatly sealed to prevent the ingress of water. If one applied a dewatering fluid , this would also help. Sometimes, guys, I think we try to make things too difficult for ourselves. And, yea, Nat was living in Minnisota when he built his first cozy. Ernie & Cozy3 in Cape Towncozy_builders@hpwarhw.an.hp.com Date: Sun, 9 Feb 1997 09:23:53 -0500 (EST) From: Wschertz@aol.com Subject: Re: COZY: Wing attach bolt pockets/drain holes There is a nice tool that can be used to make perfectly fitting recessed cover plates for these access holes. It is a woodworking Router inlay kit, which consists of two guide bushings, and a 1/8" router bit. It is made by Freud, costs $29.95, and can be ordered from Woodworkers Supply, 1-800-853-WOOD Bill Schertz Date: Fri, 14 Feb 1997 15:59:58 +0000 From: robin du bois Subject: Re: COZY: Robin's Cool Tiedowns! (fwd) Jeff S Russell wrote: > > robin du bois wrote: > > Jeff, what sort of EZ tie downs do you use that don't require you to > > bring anything with you? I want some! > > Robin, I did not say that I like my tie down system better because it > requires me not to bring anything in the airplane when I go places with it. "I do not like that kind of tiedown because of trying to reach rope or chains at any hard surface tiedowns (they don't reach) They work fine if you plan to bring your own rope or plan to tiedown in the grass with your own twist in tiedowns that you place were it reaches them." -- > I have small hole/tubes behind the wing spar about 16" inboard of > the winglets that I insert (bring with me) I-bolts and washers and nuts that > go through the tube and then reach a standard width tiedown. I also > carry rope and grass twist in tiedowns when planning to go to a.. Thanks Jeff, that seems like a great idea. I guess I will keep my tiedowns though, I'd rather carry a couple if light lines and snap them on than a handfull of loose hardware. Not that it is not a great idea, I just tend to lose stuff like that! Also leave it on the airplane when I should not... Have fun, build safe, fly soon! Robin du Bois Allegro Avionics (Engine temperature and fuel monitors.) Cozy II-place N22AZ Date: Sat, 15 Feb 1997 18:42:14 +0000 From: robin du bois Subject: [Fwd: Re: COZY: Robin's Cool Tiedowns!] This is a multi-part message in MIME format. --------------7192368359B Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit James, I got your request for plans, you shold have them by return mail, and I like your idea in the attached mail very much. You meant this to go to the group not to me so I will forward it on. Robin du Bois Cozy22AZ Allegro Avionics (engine and fuel monitors) --------------7192368359B Content-Type: message/rfc822 Content-Transfer-Encoding: 7bit Content-Disposition: inline Received: from arl-img-7.compuserve.com (arl-img-7.compuserve.com [149.174.217.137]) by dakotacom.net (8.7.5/8.7.3) with SMTP id SAA23389 for ; Sat, 15 Feb 1997 18:00:39 -0800 (PST) Received: by arl-img-7.compuserve.com (8.6.10/5.950515) id UAA25027; Sat, 15 Feb 1997 20:06:08 -0500 Date: Sat, 15 Feb 1997 20:06:00 -0500 From: INFINITY Aerospace Subject: Re: Re: COZY: Robin's Cool Tiedowns! To: robin du bois Message-ID: <199702152006_MC2-114E-F648@compuserve.com> Content-Type: text Hi All, >I guess I will keep my tie downs though, I'd rather carry a couple if light lines and snap them on than a hand full of loose hardware. Not that it is not a great idea, I just tend to lose stuff like that! Also leave it on the airplane when I should not...< How about moving Robin's design out to within 16" or so of the winglet and mount it to a pivot block on the front of the wing 'C' spar ala Cessna Cardinal RG? It can be done even if your wing is finished. No extra hardware to carry and forget through the wings (Robin's concern), which, by the way, has been used in canards for 15+ years, and moving Robin's design outboard better locates over a tie down (Jeff's and others concern). HTH. Infinity's Forever, EAA Member EAA Technical Counselor JD EAA Flight Advisor AOPA Member Test Pilot James D. Newman, President LCDR F-14 USNR INFINITY Aerospace Mailing Address: P. O. Box 12275 El Cajon, CA 92022 Shipping Address: 1750 Joe Crosson Drive, D-2 El Cajon, CA 92020 (619) 448-5103 PH & FAX E-Mail -- INFINITY_Aerospace@CompuServe.com Checkout our many products, Stick Grips, Retractable Main Landing Gear and the Infinity 1 Home Page -- http://Ourworld.CompuServe.com/Homepages/INFINITY_Aerospace --------------7192368359B-- Date: Fri, 21 Feb 1997 08:54:11 +0000 From: robin du bois Subject: Re: COZY:Goofups Now that I can be assured of total attention I want to poit out for all the people who requested Tiedown drawings, Stop!!! I am a dislexic dolt, Put the tiedown on the OUTBOARD bolt! Not on the inboard as I said in my notes (twice) on the drawings...Marc, could you please note this in the web page? I have visions of people cursing me from coast to coast... Robin (psst! hey! want to buy a thermogulator? shhhhh!)du Bois Cozy22AZ From: UYFA59A@Prodigy.com ( JAMES J CULLEN IV) Date: Tue, 4 Mar 1997 16:35:02, -0500 Subject: COZY: Spar Cap Problems? -- [ From: James J. Cullen, Ph.D. * EMC.Ver #2.5.3 ] -- Hi Group: I just started building my Mark IV wings and may have a small problem with the upper spar cap. I was wondering if anyone else had encountered the same problem and, if so, how you went about solving it. As you know, the upper surface of the wing, when viewed along its length , has a dip in it with a low point around B.L. 67.5. This dip is intentional. The upper surface of the inboard wing core needs to slope upward to meet the engine cowling. After I had laid up my upper spar cap, I was sanding the surface to eliminate the stair-step bumps caused by the different lengths of UND tape (using 40-grit and a Black & Decker palm sander -- works great!). I use a 16" ruler to check my work as I go, trying to sand the spar cap so that it is sufficiently flat so as to pass the 1/16" per foot bump/dip criteria described in Chapter 3. Over most of the length of the spar cap, this works out just fine. However, there's a 12-16" section of the cap -- centered on the outboard hardpoint -- that won't meet the dip criteria because of the bend in the upper surface of the wing. Is this a problem? Should I add additional plys of UND tape to fill the dip and bring it into conformance with the dip criterion or, because of the way the wing is designed, is it OK to leave it as is. How have you handled this problem, assuming that you have run into it? Many thanks, Jim Cullen UYFA59A@Prodigy.Com "The road to the launch pad is littered with the remains of many a promising career." Date: Wed, 5 Mar 1997 12:34:50 -0500 From: Phillip.Johnson@lmco.ca (Phillip Johnson) Subject: COZY: Spar Cap Problems? Jim Cullen Writes: > Over most of the length of the spar cap, this works out just fine. > However, there's a 12-16" section of the cap -- centered on the > outboard hardpoint -- that won't meet the dip criteria because of > the bend in the upper surface of the wing. Is this a problem? > Should I add additional plys of UND tape to fill the dip and bring > it into conformance with the dip criterion or, because of the way > the wing is designed, is it OK to leave it as is. How have you > handled this problem, assuming that you have run into it? My experience was that the fibres tend to collect at the inside radius of the corner resulting in a slightly higher density of fibres in this region. This depletes the outer radius which is probably what you are encountering here. This part of the spar cap is probably the highest stressed region of the spar and any extra strength in this region is not going to waste. Be cautious however, that you do not add too many fibres in this region because you will later transition this region with the centre section spar. You don't say by how much this region is depleted of fibres. If it's small then leave it. You can always add UNI cloth on top of the skin without compromise to structural integrity it just doesn't look as good before you apply the filler finishing coat. Phillip Johnson. From: UYFA59A@Prodigy.com ( JAMES J CULLEN IV) Date: Tue, 11 Mar 1997 21:04:33, -0500 Subject: COZY: Assembling Wing Cores? Use Care! -- [ From: James J. Cullen, Ph.D. * EMC.Ver #2.5.3 ] -- Hello Crew: About a week ago, I posted a message describing a problem that I was having in getting the upper spar cap of my first wing to pass the 1/16- inch-per-foot dip criterion. (A tip of the hat to Phillip Johnson for his suggestions.) It is at this location (B.L. 67.5) that the inboard core (FC1) and especially the trailing edge of the wing bends upward to match the shape of the engine cowling. I managed to correct the problem by adding four additional plys of UND tape centered on the outboard hardpoint; the tapes were 18", 12", 9", and 6" long, respectively. I blended them into the spar cap with 40-grit on a palm sander (works great) and the fix worked fine. As I was prepping the core for the skin, I noticed that the core also violated the dip criterion at B.L. 67.5 -- again, because of the bend in the upper surface of the wing. As I hardshell my wings, the fix was simple: I just added sufficient micro to the core to build up the area that was failing the dip criterion. Without getting into a religious discussion, this is one of the advantages of hardshelling. Anyway, as I try to work as accurately as I can, I wondered what kind of dip was built into the upper surface of the wing (at B.L. 67.5) **by design**. The answer can be calculated using the wing pitch data given by Nat on page 19-10 of the plans. From B.L. 67.5 to B.L. 169, the trailing edge rises from W.L. 16.95 to W.L. 18.35 -- a rise of 1.4 inches over a run of 101.5 inches or a 0.790-degree inclination off the horizontal. From B.L. 67.5 to B.L. 31 (36.5-inch run) the trailing edge rises from W.L. 16.95 to W.L. 17.5 -- a rise of 0.55 inches or an 0.863- degree inclination. Some simple trig will allow you to calculate the depth of the dip under a 1-foot ruler centered at this point. Take the average of the two angles: (0.790 + 0.863)/2 = 0.826 degrees. Find the tangent of that -- 0.01443 -- and multiply it by the half span of a 12-inch ruler (6 inches ) to get the dip: it works out to be 0.087 inches. This exceeds the 1/16" (0.0625) dip criterion -- not by much, I grant you, but what if you are off a tad when assembling the cores, such that you position core FC1 angled up a bit more than it should be? Let's do the calculation again and say that you mis-positioned FC1 by 1/4-degree. Now the average angle is (0.826 + 0.25)/2 = 0.951 degrees. The tangent of that is 0.0166 and your dip is just shy of 0.1 inches. That's approaching twice the allowed dip -- for a 1/4-degree screw-up. Ouch. Alas, unless somebody can find an error in my calculations (I hope you can!), I think we have a minor problem designed into the wing cores. If you're hardshelling, the solution is simple: add micro and check the dip criterion before skinning. If you're not hardshelling and you've already built your wings, do a quick dip check on the trailing edge at B .L. 67.5 to see if you're in compliance; my sympathy if you're not. If you haven't built your wings yet, check the dip criterion at B.L. 67.5 as you are assembling your cores in the wing jigs. It doesn't take much tweaking to bring the inboard core (FC1) into compliance with the dip criterion (or to throw it off, for that matter) -- probably less than half a degree. But, it's easier to fix it when assembling the cores than it is to have to fill in the dip later. By the way -- don't just blow off the fix. The area of the wing being discussed -- at B.L. 67.5 -- is probably one of the highest stressed areas of the wing and, as Nat shows in Chapter 3, this area **must** pass the dip criterion -- from the spar back to the trailing edge -- or you have a problem that must be fixed. Hope I haven't stirred up a hornet's nest. Regards, Jim Cullen UYFA59A@Prodigy.Com P.S. -- I just checked out Marc's web page for the first time today and it blew my socks off. (Damn socks -- they've got to be around here somewhere...) If you haven't gotten up to speed with a web browser yet, his page alone is worth the price of admission! From: Marc J. Zeitlin Subject: COZY: Assembling Wing Cores? Use Care! (fwd) Date: Wed, 12 Mar 97 11:08:03 EST Jim Cullen wrote: >By the way -- don't just blow off the fix. The area of the wing being >discussed -- at B.L. 67.5 -- is probably one of the highest stressed >areas of the wing and, as Nat shows in Chapter 3, this area **must** >pass the dip criterion -- from the spar back to the trailing edge -- or >you have a problem that must be fixed. I will take exception to this admonishment, if I understand Jim's explanation correctly. Basically, what you've got here is a dihedral joint (of around 0.1 - 0.2 degrees), not a "dip" or anomaly in the surface of the wing. This is no more a "dip" than the joint between the wing and the winglet is, and you certainly would not fill that with micro until a ruler showed no more than 1/16" of light under it at any point when you held it between the two surfaces (obviously this is a rediculous example!). What the manual says about "dips" is related to local structural problems that may crop up due to fiber irregularities, as well as turbulent airflow generation (especially on the canard) due to airflow seperation. Neither of these is the case in this instance. When you've got a designed in discontinuity like this one, you measure the dips on one side, then measure the dips on the other side, but don't bother trying to ensure that you don't have a dip across it - it's there by design! I put a small radius of micro in that area so that there would be no "corner", but I've got no more than a 1/64" - 1/32" dip in the wing surface on either side of BL 67.5". Now, I don't think that filling with 1/16" - 1/8" micro in that area is going to do any harm, but it's unnecessary weight, and I think that Jim's message may cause unnecessary alarm. I really don't think there's any engineering issue here - this is the way it's _supposed_ to be. Other Engineers - chime in and flame me if I'm off base here! >P.S. -- I just checked out Marc's web page for the first time today and >it blew my socks off. Why, thank you. -- Marc J. Zeitlin Email: marcz@an.hp.com From: UYFA59A@Prodigy.com ( JAMES J CULLEN IV) Date: Wed, 12 Mar 1997 11:31:29, -0500 Subject: Re: COZY: Assembling Wing Cores? Use Care! (fwd) -- [ From: James J. Cullen, Ph.D. * EMC.Ver #2.5.3 ] -- With regards to my concern over the dihedral in the top surface of the wings at B.L. 67.5, Marc commented that: > I will take exception to this admonishment, if I understand Jim's explanation correctly. (You do -- Jim). Basically, what you've got here is a dihedral joint (of around 0.1 - 0.2 degrees), not a "dip" or anomaly in the surface of the wing. This is no more a "dip" than the joint between the wing and the winglet is, and you certainly would not fill that with micro until a ruler showed no more than 1/16" of light under it at any point when you held it between the two surfaces (obviously this is a rediculous example!). True, but look at the amount of reinforcing layups that you perform in this stress-critical area to keep the winglets attached to the wings. We do not perform any such layups on the wing at B.L. 67.5 and yet this is also a stress-critical area. The unreinforced upper skin will be in compression at B.L. 67.5 and, if it violates the dip criterion (which it does), might it not be expected to buckle? (Obviously there's a safety factor built into the dip criteria. The Mark IVs that are flying aren't falling out of the air!) Markc has an interesting perspective here, but I'm still concerned. > What the manual says about "dips" is related to local structural problems that may crop up due to fiber > irregularities, as well as turbulent airflow generation (especially on the canard) due to airflow seperation. Neither of these is the >case in this instance. > > When you've got a designed in discontinuity like this one, you measure the dips on one side, then measure the dips on the >other side, but don't bother trying to ensure that you don't have a dip across it - it's there by design! I guess that's my concern, Marc. Should it be there -- by design? > I put a small radius of micro in that area so that there would be no "corner", but I've got no more than a 1/64" - 1/32" dip in the > wing surface on either side of BL 67.5". Interesting! Do you have any idea as to how you managed that, considering that the math says your dip should be deeper? Is there some technique that you used in checking core alignment that might benefit the rest of us? > Now, I don't think that filling with 1/16" - 1/8" micro in that area is going to do any harm, but it's unnecessary weight, and I think >that Jim's message may cause unnecessary alarm. I really don't think there's any engineering issue here - this is the way it's >_supposed_ to be. > > Other Engineers - chime in and flame me if I'm off base here! Apologies, of course, if I caused unnecessary alarm. My intention was to cause necessary alarm (?!), if such alarm is justified. I see Marc's viewpoint and he may be correct. Perhaps Nat intended the dihedral just as it is and perhaps there is no cause for structural concern. Still, as an engineer (chemical, not structural) I get nervous when I see weak structures (2 plys of UND) in compression in stress-critical areas. What do the rest of you think. Am I off base or is there a potential conceren here? (If the former, I'll go creep back into the woodwork and skin my wing). Jim Cullen UYFA59A@Prodigy.Com "The road to the launch pad is littered with the remains of many a promising career." Date: Wed, 12 Mar 1997 13:01:10 -0500 (EST) From: SWrightFLY@aol.com Subject: Re: COZY: Assembling Wing Cores? Use Care! (fwd) To avoid walking into the shop one day and "dicovering a dip or bump in the wing or canard cores which you must then must find a "fix" be careful during core assembly. Cut all the cores about 1/16" larger by enlarging the templates by that amount. Take a lot of care as the wing and canard cores are assembled and don't stop "fussing" with them until they appear perfect. Most of the bumps and dips can be avoided by not rushing this step. After all the cores are assembled and out of the forms- sight down the span with a flash light (turn out the lights in the shop) you will see the shadows (low spots) and you can gently sand the bare foam down with a 5 ft. long sanding block 4 inches wide to get near perfect contours before you lay-up the glass. If the bare foam is straight and true the entire wing when glassed will be straight. The extra time on the front end will save a lot of time during the finishing process. Steve Wright Date: Wed, 12 Mar 1997 21:08:19 +0000 From: robin du bois Subject: Re: COZY: Assembling Wing Cores? Use Care! (fwd) Just a thought...when I was building my Cozy it never occurred to me to apply the dip/joggle/bump criterion to parts of the plane that have 'em designed in! Are you all sure you need to do this? rdb Date: Wed, 12 Mar 1997 21:55:30 +0000 From: David Domeier Subject: Re: COZY: Assembling Wing Cores? Use Care! (fwd) Jim, re "What do the rest of you think. Am I off base or is there a potential conceren here?" I am not an engineer of any sorts but I do build and fly these bed sheet and honey airplanes. (LEZ in 1982, Cozy MKIV under construction) It is my opinion, not being the builder of a perfect airplane, although I would like to, that these designs are very strong and safe if built reasonably close to the plan. I too was concerned about the dip at BL 67.5, but that's the way this machine is. RAF reviewed the plan before Nat started selling it and Burt Rutan gave it his blessing, and that's good enough for me. Let me tell a quick short story about the LEZ. I was makeing an approach to this airport that had a crossing runway that was obscured by a row of trees. Just as I was in the flare, a red WACO type airplane came around the corner from the crossing runway and was headed right at me. My brain couldn't believe what I was seeing but my hand was moving the throttle forward as I rolled to the left to miss this guy. After landing, I approached the pilot who was now at the gas pump with his airplane. It seems he was taking off, the engine quit and he decided to roll to the gas pump, as he suspected he was out of fuel. I said nothing and walked away....there are all kinds of nuts and some of them are pilots. Anyway, as I was waiting for my ride, I sacker out under my left wing and in looking up could not believe my eyes once again. The left lower winglet was all but missing. I had dragged it in the grass when I rolled to the left to miss the WACO. It was sheered down as if someone had taken a giant sander to it. My confidence in the design was once again renewed as it had been a number of times before. It is indeed a good, forgiving flying machine and I can't wait the get this MKIV flying. I do miss my LEZ since donating it to a museum in favor of side by side seating. dd From: Marc J. Zeitlin Subject: Re: COZY: Assembling Wing Cores? Use Care! (fwd) Date: Wed, 12 Mar 97 17:25:46 EST James J. Cullen wrote: >We do not perform any such layups on the wing at B.L. 67.5 and yet this >is also a stress-critical area. The unreinforced upper skin will be in >compression at B.L. 67.5 and, if it violates the dip criterion (which it >does), might it not be expected to buckle? No. The wing spar takes essentially 100% of the bending loads on the wing. The wing skin takes 100% of the torsional loads, but not the bending loads. The flexing of the wing skin in this area due to bending loads will be minimal, and the stress in the skin will be minimal. >I guess that's my concern, Marc. Should it be there -- by design? Well, Burt Rutan put it there on the L.E., from which this design is derived, and even if it was an oversight on the L.E., there have been enough of them (and COZY's) flying for a long enough time that I'd say we can conservatively say that it's perfectly safe. There has NEVER been a structural failure of a correctly built V.E., L.E. or COZY. >> I put a small radius of micro in that area so that there would be no >"corner", but I've got no more than a 1/64" - 1/32" dip in the > wing >surface on either side of BL 67.5". > >Interesting! Do you have any idea as to how you managed that, >considering that the math says your dip should be deeper? I'm not claiming that my "corner" isn't deeper than that if you put a 12" straightedge 6" on either side of BL 67.5 ; I've got a "normal" BL 67.5 joint - I'm saying that if you keep the ruler _completely_ on one side or the other of BL 67.5, I've got very small dips. >........... Is there some >technique that you used in checking core alignment that might benefit >the rest of us? No - see the above paragraph. >Apologies, of course, if I caused unnecessary alarm. My intention was >to cause necessary alarm (?!), if such alarm is justified. Necessary alarm is good :-). >........... Perhaps Nat intended the dihedral just >as it is and perhaps there is no cause for structural concern. This is my viewpoint - but replace "Nat" with "Burt Rutan". >............ Still, >as an engineer (chemical, not structural) I get nervous when I see weak >structures (2 plys of UND) in compression in stress-critical areas. "Weak" is relative - if it's strong enough to perform the task at hand, it's not "weak". The 3 - 4 plies of UNI in this area have been proven over and over to work in the configuration and design that exists. My $0.04. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Wed, 12 Mar 1997 15:26:00 -0800 From: berkut@loop.com Subject: Re: COZY: Assembling Wing Cores? Use Care! (fwd) >"Weak" is relative - if it's strong enough to perform the task at hand, >it's not "weak". The 3 - 4 plies of UNI in this area have been proven >over and over to work in the configuration and design that exists. > If you'll allow me, a quick story on just how strong it is. A close personal friend of mine used to like flying low level. Really, really low. Once flying a Long EZ across the desert at 5 feet or so he raised one wing to clear a cactus. The low wing hit a scrub pine and took off the lower winglet. The wing flexed backwards, the skins innboard of the aileron blew off the core and separated at the trailing edge. He flew to the closest airport, examined the damage, duct taped the TE back together and flew home. He re-skinned the area, examined the spar closely, and the airplane was returned to service. The damaged area never showed another problem. Date: Wed, 12 Mar 1997 21:38:00 -0500 (EST) From: StetsonE@aol.com Subject: Re: COZY: Assembling Wing Cores? Use Care! (fwd) In a message dated 97-03-12 14:08:06 EST, Jim writes: Bunch of stuff snipped: > The unreinforced upper skin will be in > compression at B.L. 67.5 and, if it violates the dip criterion (which it > does), might it not be expected to buckle? (Obviously there's a safety > factor built into the dip criteria. The Mark IVs that are flying aren't > falling out of the air!) Markc has an interesting perspective here, but > I'm still concerned. I would agree with Marc on this point. As I understand it, all the Cozys, and Long-EZs have the same wing design, and they all have the dip you mentioned. Don't be concerned that since the Mark IV is a new design that it hasn't been adequately proven. The wings, at least, have stood the test of time and a good deal of abuse with no problems. From an engineering standpoint the dip may be a structural weak spot, but it's never shown to be a problem in the 1000 (2000? 3000?) sets of wings that have flown. The center spar is another component where, not a dip, but a bump is designed in. The bottom of the spar has a massive bump where it angles upward at about BL 10 (on the LE). As Marc said, its designed that way, so don't worry about it. Stet Elliott stetsone@aol.com Perpetual Long-EZ builder (but getting close, very, very close!) From: UYFA59A@Prodigy.com ( JAMES J CULLEN IV) Date: Mon, 17 Mar 1997 16:58:15, -0500 Subject: COZY: Assembling Wing Cores -- [ From: James J. Cullen, Ph.D. * EMC.Ver #2.5.3 ] -- OK -- OK -- I get the hint. The dip in the upper surface of the wing at butt line 67.5 is not a problem! Carolyn and I went ramp walking at Northtown Saturday (North Las Vegas Air Terminal -- VGT) and ran into Jeff Glynn (Cozy 3-Place) and his hangermate (Long-EZ). We checked the dip at B.L. 67.5 on both aircraft and, even after contouring, priming and painting, the location wouldn't pass the dip criterion on either aircraft). As both A/C have hundreds of hours on them, obviously this dip is not a problem. The only dip that would appear to be a problem is me. Pardon me for a moment. There seems to be some yolk dripping off my chin. Still, being anal retentive, I did fill the area so that it passes the dip criterion on my own wing. Actually, you can only do this down to within a few inches of the trailing edge. At that point, the dip has already been glassed into the bottom skin. Definition: Anal Retentive: Someone whose workmanship is better than your own. Sigh. Anyway -- thanks for being a soundingboard, crew. It's nice to have someone(s) to bounce these ideas off of. Best wishes, Jim Cullen "The road to the launch pad is littered with the remains of many a promising career." Date: Sun, 30 Mar 1997 07:16:25 -0800 From: marcna Subject: COZY: Wing Float Over the past few days I have been talking with Todd Morgan, Jeff Russel, and J.D. about the front/inside wing rib. One thing very interesting came out of our discussion. When the Cozy wing is in turbulence or when banking the aircraft sharply the leading edge wing root deflects a great deal and can be noticed moving up and down where the wing meets the strake. Because of this gap it is also a source of drag. = I was also told that the European version of the Cozy has a =BD inch bolt= to hold the leading edge of the wing to the leading edge of the strake. = Has anyone built a U.S. version with the leading edges attached to stop this wing float. = Marc Parmelee N425CZ From: Marc J. Zeitlin Subject: COZY: Wing Float (fwd) Date: Mon, 31 Mar 97 17:24:28 EST Marc Parmelee wrote: >........ about the front/inside wing rib. One thing very >interesting came out of our discussion. When the Cozy wing is in >turbulence or when banking the aircraft sharply the leading edge wing >root deflects a great deal and can be noticed moving up and down where >the wing meets the strake. This is due to the torsional load applied to the wing from increasing angles of attack. The moment coefficient from the positively cambered wing causes the twisting of the wing. Since turbulence can cause high load factors (G's), and since highly banked turns cause high G loading, you will see this type of motion. This is not unique to the COZY - all the V.E.'s and L.E.'s will exhibit the same effect, as will any aircraft that relies purely on the wing spar to wing joint for it's torsional resistance. >......... Because of this gap it is also a source of >drag. Well, yeah, but the percentage of time you spend at anything other than one G (unless you're flying acrobatics or combat) is infinitesimal. It's hard to imagine that this will substantially change your average speed in any noticable way. Maybe, if it keeps you from taping the wing/strake joint to prevent airflow from the bottom to the top of the wing....... then you might notice a small effect. >I was also told that the European version of the Cozy has a =BD inch bolt >to hold the leading edge of the wing to the leading edge of the strake. This sounds familiar - I think we had a discussion about this topic a year or more ago. It was in reference to the European requirement for the addition of this bolt. >Has anyone built a U.S. version with the leading edges attached to stop >this wing float. I don't know (of course, after expounding at great length, I don't answer the _one_ question you've actually got :-) ) - if someone else has heard of this, I'd certainly like to hear about it. Adding a "bolt" or some other kind of structural member to prevent this type of torsional motion of the wings is a _MAJOR_ change to the structure of the COZY. By doing this, you are changing the stress flow due to torsional moments from flowing through the spar to flowing through the wing skin and strake skin. While Euro-Cozy's might be flying perfectly well with this modification, I'd be loath to make a structural change like this without some indication that analysis and verification testing has been performed to ensure that changing the stress flow as this does doesn't cause some other (possibly subtle) change or weakness. Given all the V.E.'s, L.E.'s and COZY's in the U.S. flying with this characteristic, I'd recommend against it without a lot more info. My $0.02. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Mon, 31 Mar 1997 17:40:21 -0500 From: Mahan Subject: Re: COZY: Wing Float (fwd) Yes, we did have this discussion a while back, and as I remember, the consensus was to leave the structure alone -- no "improvements" needed. The strake doesn't really have a lot of structure in it, ans isn't necessarily stressed for these kinds of loads. Fred in Florida Long-EZ N86LE Defiant project Date: Tue, 01 Apr 1997 07:32:57 -0500 From: william l kleb Organization: NASA Langley Research Center Subject: Re: COZY: Wing Float Marc J. Zeitlin wrote: > > ... Adding a "bolt" ... is a _MAJOR_ change ... it's the old "3 points define a plane" thing... ever notice how a four-legged table rocks? at moments during its life just two legs have to carry all the load. if, however, like photographers, you decided to use a tripod, i.e., three legs, then all the legs would share the load equally at all times. gross simplification, but i think it makes the point (?) -- bil Date: Tue, 1 Apr 1997 16:22:45 -0500 From: Phillip.Johnson@lmco.com (Phillip Johnson) Subject: COZY: Wing Float The issue of wing float has bugged me for some time. I am aware of the European requirement for the additional bolt and have thought to install it myself. Marc Z writes: > This is due to the torsional load applied to the wing from > increasing angles of attack. The moment coefficient from the > positively cambered wing causes the twisting of the wing. Since > turbulence can cause high load factors (G's), and since highly > banked turns cause high G loading, you will see this type of > motion. I am assuming that the wing pitches downwards in high G maneouvers but I think that the sweep back would dominate over the aerodynamic moment caused by the wing camber. Either way this could result in control reversal if it were to become bad enough. Bill Kleb Writes: > it's the old "3 points define a plane" thing... ever notice how a > four-legged table rocks? at moments during its life just > two legs have to carry all the load. This is true for a rigid body. Clearly our system is not rigid as depicted by the differential movement between the wing and strake. Under these circumstances additional support will enhance the torsional stiffness. One of the differences between the Long-eze and the Cozy is the difference in design speed. The Cozy has a maximum design speed of 216 mph which is dangerously close to the Vne of 220 mph, whereas the design speed for the "Long" is well below its Vne. Are we bordering on the edge of disaster? Half a dozen flying Cozy IV's is hardly a statistical sample. There is one, US built, European Cozy that appears at Oshkosh each year, maybe a discussion with the owner may put this subject to rest. My $0.02 worth. Phillip Johnson Date: Tue, 01 Apr 1997 16:51:40 -0800 From: berkut@loop.com Subject: Re: COZY: Wing Float > The Cozy has a maximum > design speed of 216 mph which is dangerously close to the Vne of 220 > mph, whereas the design speed for the "Long" is well below its Vne. > Are we bordering on the edge of disaster? Half a dozen flying Cozy > IV's is hardly a statistical sample. > The listed Va of the long is far short of it's Vne, but there are _plenty_ of big engined Longs that are flying at 220 and more. The Berkut uses exactly the same mounting system and we're crusing at 265-270, and the PFA in England just certified it to 10 g's plus/minus at a 2000 lb gross with a 200% safety margin. From: Epplin_John_A@hpmail1.90.deere.com Date: Wed, 9 Apr 97 10:51:24 -0500 Subject: COZY: Cozy: Wing construction Just to break the monotony for those of us that are not at sun-n-fun. I finished the structure of one wing and am ready for the cap strip on the other. A couple of things I did that seemed to work well. I made the clearance cutouts in the jigs for the leading edge overlap about twice as deep as was shown on the plans. My hands would not fit in the area shown. I also glued the jigs to the bottom skin with bondo at least 3 places each jig so the area that I cut out would not have any function anyway. The other item may have some detractors. I did not put any micro in the trailing edge joggle when I laid up the bottom surface. This made a perfect place to lay a piece of 1/2 in. thin wall electrical conduit. I bondoed this in place about every foot or so, using spring clamps to make sure it was in contact. I then had to make cuts in the jigs for the conduit. Used a spade bit in order not to remove any more wood than needed. This made for a straight trailing edge. Just for the sake of discussion, there has been much on the control torque tube bearings in the past. I will add another .02 to the issue. I am thinking of using the phenolic blocks specified in the plans but enlarging the hole size to accommodate 'Nyliner' snap-in bearings. these are quite inexpensive and will be replaceable if they ever do wear. The ones I am considering are made from something called "polymer-642" with a temp range of -40 to 200 f and available from MSC. Anybody have any comments? Bored in the Quad cities, waiting for Oshkosh John Epplin #467 by SERV05.SLAC.STANFORD.EDU (PMDF V5.1-8 #16063) with SMTP id <01IHI1MTP3KW00678E@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Wed, 9 Apr 1997 12:04:40 PST Date: Wed, 09 Apr 1997 13:04:40 -0800 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Cozy: Wing construction >Just for the sake of discussion, there has been much on the control torque >tube bearings in the past. I will add another .02 to the issue. I am >thinking of using the phenolic blocks specified in the plans but enlarging >the hole size to accommodate 'Nyliner' snap-in bearings. these are quite >inexpensive and will be replaceable if they ever do wear. The ones I am >considering are made from something called "polymer-642" with a temp range >of -40 to 200 f and available from MSC. Anybody have any comments? > > >Bored in the Quad cities, waiting for Oshkosh > >John Epplin #467 This is certainly an imporvement over the stock setup, but I would pose one more thing for you to consider, John. The torque tube doesn't pass through the hole in the bearing at a right angle. Furthermore, as the aileron is deflected, that angle changes. The outboard end of the tube sweeps through an arc, while simultaneously rotating. I believe the proper term for this type of motion is "it neutates" (but I could be wrong). Anyway, you get the point. A self-aligning spherical bearing takes care of these problems. I am using one made by Pobco of Worcester, Mass. that has a teflon center, in a stainless retainer. It is about as fire-restant as I could find. I bought it so long ago, that I don't remember where I got it, but perhaps a search of Thomas's Register, or the Web would turn it up. Howard Rogers A&P 2005148 From: Epplin_John_A@hpmail1.90.deere.com Date: Sat, 12 Apr 97 08:49:10 -0500 Subject: COZY: Heated pitot tube I am working on my second wing. Intend to us a heated pitot tube. What about mounting it about 2 ft. outboard and just forward of the center spar. About a 4 to 6 inch mast. This will place the end of the tube about even with the leading edge and at least 6 in. below it. Is this considered undisturbed air at this point? Am planning about a 2 x 4 in rectangular opening with a substantial flush mounting flange layed up with the bottom wing skin. I can then make a mount from 2024 .040 sheet with a 4130 streamlined tube with welded flange to screw to the Al. Will imbed plate nuts in the glass flange at this time. Any comments or improvements to suggest? John Epplin mk4 #467 Date: Sat, 12 Apr 1997 11:10:04 -0400 From: Jim Hocut Subject: Re: COZY: Heated pitot tube >I am working on my second wing. Intend to us a heated pitot tube. What >about mounting it about 2 ft. outboard and just forward of the center spar. >About a 4 to 6 inch mast. This will place the end of the tube about even >with the leading edge and at least 6 in. below it. Just my opinion, but it seems that putting the pitot in the nose as per plans will work just fine, and be a whole lot less hassle. In the wing you'd have to figure out how to disconnect the tubing in the rare instances that you need to remove the wings, plus there will be a lot more plumbing to do to get out to the wing than for simply going to the nose. If your concern is that the pitot will be too close to the ground when parked why not put it several inches above the center of the nose like the T-38 and some other jets. Like I said, just my opinion, and it's worth every penny you paid for it. Jim Hocut jhocut@mindspring.com Date: Mon, 05 May 1997 17:46:53 -0400 From: Paul Burkhardt Subject: COZY: Wing attach bolt pockets (fwd) and will hold them down with a couple of screws into some nutplates installed somehow (I know, it's not completely thought out yet :-) On Carl Denks plane he used the 5 ply bid layup as you suggested, but what he did to hold them down was kind of neat. He drilled a hole through the botttom of the dished out area into the opposing side. he then inserted a tubing segment, microed in place. next he found a spring that fit inside the tube( fitted all before hand I'm sure). he attached the spring to the covers with a simple hook . the hook is floxed into the 5 ply cover. when finished you can simply lift the cover up to inspect. each cover is attached to the same spring. This also provides a drain for water. Paul Burkhardt From: Epplin_John_A@hpmail1.90.deere.com Date: Mon, 12 May 97 10:00:09 -0500 Subject: COZY: Aileron cutout Just finished wing skins. What is the best way to cut out the ailerons? By hand with a hacksaw blade seems sort of crude. Saber saw with a short blade maybe. Cutoff wheel in a small die grinder? Open for any ideas John epplin Mk4 #467 Date: Mon, 12 May 1997 08:23:25 -0700 From: Rego and Noleen Burger Organization: R.N.B. Enterprises Subject: Re: COZY: Aileron cutout Must say that's my next task plus a few but found the good old hacksaw my best friend so far, I've cut almost everything with it and find hand control although slow more accurate. When doing the canopy etc.etc.etc.etc,...... Rego P.E. RSA CZ4 #139 From: Marc J. Zeitlin Subject: COZY: Aileron cutout (fwd) Date: Mon, 12 May 97 11:49:34 EDT John Epplin wrote: >Just finished wing skins. What is the best way to cut out the ailerons? By >hand with a hacksaw blade seems sort of crude. Saber saw with a short blade >maybe. Cutoff wheel in a small die grinder? I have found that I get the fastest, cleanest, straightest cuts with (ta-da) the damn hacksaw blade in a holder :-). The only time I'll use a die grinder with a cutoff wheel (or the dremel tool with a cutoff wheel) is if I can't get the hacksaw blade into the area to cut. I _NEVER_ use a sabre saw - I've lifted the glass up off the foam on the upswing of the reciprocation once too often (meaning once). I hold the hacksaw blade almost parallel to the surface I'm cutting - this minimizes pullup on the glass and ensures a straight cut. Also, I usually cut on the backstroke (the teeth pointing back towards me) rather than on the push stroke. This ensures that the blade is pulled straight on the cut, and doesn't bend while cutting. I was able to cut the whole trailing edge of the wing in about two minutes to within 1/16" (finished with a 3' sanding block) and the ailerons took about 5 minutes each (cut right down the line, and also finished with sanding blocks, since the plans call for about 0.1" spacing). -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Mon, 12 May 1997 09:53:13 -0700 From: Eric Westland Subject: Re: COZY: Aileron cutout At 10:00 AM -0500 5/12/97, Epplin_John_A@hpmail1.90.deere.com wrote: >Just finished wing skins. What is the best way to cut out the ailerons? By >hand with a hacksaw blade seems sort of crude. Saber saw with a short blade >maybe. Cutoff wheel in a small die grinder? > >Open for any ideas > >John epplin Mk4 #467 John, I agree with everything Marc said (use the hand-held hacksaw blade). I did one thing extra and that was to clamp/hot glue some particle board along the cut line for straight edges. When you hot glue, place the bead along the back edge of the wood, not under it as it will be tough to get off otherwise. I addition, since the rudders have the same cut measurements on both sides of the winglet, I cut out a board that I could glue to the winglet for a guide. I located the two spots along the trailing edge where you would start/end cutting out the rudder, set the board in place, cut out one side, moved the board and cut out the other. It worked well. One last thought - as Marc said, the cut will have to be widened to get the 0.1" gaps, but you may want to wait to do that until you glass in the reinforcing rib layups. Oops, one more last thought. Ron Kidd suggested to me that when I did the rib layups, to add a layer if carbon fiberglass on the area of each hinge. This was to add stiffness. Ron told me it would keep this area of the finish from cracking from the flexing. -eric Eric Westland Cozy Mark IV - Still sanding Mukilteo, Washington (425) 513-0941 From: "Dalrymple, Mark J" Subject: COZY: Aileron & Rudder Cutout Date: Mon, 12 May 97 10:20:00 PDT Hello Builders, One easy way to cut out the ailerons and rudders is to use a FEIN SANDER with it's cutting blade. I clamped a metal straight edge on the line for cut. The straight edge was used as a guide for the cutting blade. The results was a straight and less than 1/16" cut. Simple.... :) Hope this helps, Mark Dalrymple In short "Mark from Orange" Date: Mon, 12 May 1997 10:43:30 -0700 From: Richard Riley Subject: Re: COZY: Aileron cutout We've had terrific success with the "Fine" brand detail sander with a round cut off blade attached. They're expensive, $200 for the sander, $40 for the blade, but the blade lasts almost forever. They remove a _very_ narrow curf, cut quickly and you can put it against your hand and not hurt yourself. >A way some builders in this area have done the cuts is with a sturdy >sheetrock knife and a stout straightedge that is well held down or >anchored. It goes quite quickly, and the cuts are straighter than you >can get with a hacksaw. > >Fred in Florida > -- Richard Riley Renaissance Composites, Inc. 3025 Airport Ave Santa Monica CA 90405 310.391.1943 "Who the hell wants to hear actors talk?" Jack Warner, 1928 See the Berkut at http://www.berkut.com Date: Mon, 12 May 1997 14:15:37 -0400 From: Tom Teek Subject: COZY: Aileron cut Fred beat me to it! Razor knife is the way to go. Do several passes to make the cut in to the skin. If you have a razor saw.finish up with it as it gives a good gap. Use this method on the rudders as well. It worked great for me. Tom Date: Mon, 12 May 1997 13:06:03 -0700 From: Mahan Subject: Re: COZY: Aileron cutout A way some builders in this area have done the cuts is with a sturdy sheetrock knife and a stout straightedge that is well held down or anchored. It goes quite quickly, and the cuts are straighter than you can get with a hacksaw. Fred in Florida Date: Mon, 12 May 1997 16:45:26 -0400 From: INFINITY Aerospace Subject: COZY: Re: Aileron cutout Hi John, Eric and All, >Just finished wing skins. What is the best way to cut out the ailerons? By hand with a hacksaw blade seems sort of crude. Saber saw with a short blade maybe. Cutoff wheel in a small die grinder?< I like using my Makita cordless circular saw with a 3 3/8" diameter diamond tile cutting blade (Part No. 724950-8C) - makes a very thin cut. Just bondo or hot glue a low profile straight edge guide the length, and offset from, the aileron or rudder cut line to guide the circular saw, setting the cut depth just deep enough to cut through the glass skin. Then finish the foam cut below the glass skin with a knife. I like thin cuts that I can control the width of latter, if need be. >Oops, one more last thought. Ron Kidd suggested to me that when I did the rib lay ups, to add a layer if carbon fiberglass on the area of each hinge. This was to add stiffness. Ron told me it would keep this area of the finish from cracking from the flexing.< Beware / be careful of using carbon against metal and bolting through carbon for corrosion reasons. Maybe use 'S' glass for a little more strength if you are concerned. Rick Roberts uses a lot of carbon, maybe he can add $0.02. Infinity's Forever, JD Date: Mon, 12 May 1997 14:07:19 -0700 From: Eric Westland Subject: Re: COZY: Re: Aileron cutout At 4:45 PM -0400 5/12/97, INFINITY Aerospace wrote: > Beware / be careful of using carbon against metal and bolting >through carbon for corrosion reasons. Maybe use 'S' glass for a little >more strength if you are concerned. Rick Roberts uses a lot of carbon, >maybe he can add $0.02. > Thanks JD. Fortunately (blind luck) I put my carbon between my regular bid reinforcements. -eric Eric Westland Cozy Mark IV - Still sanding Mukilteo, Washington (425) 513-0941 Date: Mon, 12 May 1997 17:22:18 -0400 (EDT) From: DFinn7971@aol.com Subject: Re: COZY: Aileron cutout (fwd) In a message dated 97-05-12 11:52:03 EDT, marcz@hpwarhw.an.hp.com (Marc J. Zeitlin) writes: << I _NEVER_ use a sabre saw - I've lifted the glass up off the foam on the upswing of the reciprocation once too often (meaning once). I have also lifted the glass off the foam using a saber saw. This caused me to utter many kerfs (as in "Kerf you Red Barron). I did find that using a metal cutting blade with its fine teeth in the saber saw. This seemed to minimize the problem. But still, I prefer the method Mark details. below with the following addition. I hold the hacksaw blade almost parallel to the surface I'm cutting - this minimizes pullup on the glass and ensures a straight cut. Also, I usually cut on the backstroke (the teeth pointing back towards me) rather than on the push stroke. This ensures that the blade is pulled straight on the cut, and doesn't bend while cutting. >> It is often possible to bondo or clamp a straightedge to the work piece. I hold the blade against the straightedge and saw back and forth. I found that this makes it easy to get a straight cut. I use a venneering sawfor the tight work in the corners. Dick Finn Subject: COZY: aileron cut out From: gmellen@juno.com Date: Mon, 12 May 1997 22:37:02 EDT For cutting out my ailerons I purchased a razor back saw at a local hobby shop. Worked great and I only spent a couple of bucks on the thing. I used it as Marc described the hacksaw blade and with its stiff back I got nice straight cuts. George Mellen Date: Mon, 12 May 1997 23:58:51 -0400 From: Rick Roberts <102503.1561@compuserve.com> Subject: Re: COZY: Aileron cutout (fwd) & Graphite First on the duel, I volunteer to be the second for either party. Blunderbusses from ballon, now that sounds like fun. On the graphite in the hinge area. Pretty good idea!, embedding in glass is also required. However, you must install the fasteners wet with primer also. Other wise you've still got aluminum and graphite together. Have fun, Rick Roberts P.S. Whose turf for the duel? We've got a great balloning area out here in the Del Mar area of San Diego! From: "Krasa-1, Paul" Subject: RE: COZY: Re: Aileron cutout Date: Tue, 13 May 1997 09:44:27 -0400 > JD writes >I did the rib lay ups, to add a layer if carbon fiberglass on the area of >each hinge. This was to add stiffness. Ron told me it would keep this >area of the finish from cracking from the flexing.< > > Beware / be careful of using carbon against metal and bolting >through carbon for corrosion reasons. Maybe use 'S' glass for a little >more strength if you are concerned. I have to agree. Carbon Fiber has a galvanic potetial with AL, Ferrious Steel and Stainless Steel. Carbon fiber against a metal will cause galvanic corrosion, so to prevent this place a layer of fiberglass between the metal and the carbon and do not use any bolted joints through carbon fiber. If you decide to strengthen useing arimid fiber (Kevlar), you will need to buy tooling specially designed to cut this type of fiber. Paul Krasa Long EZ 214LP > > >Infinity's Forever, > > Date: Tue, 13 May 97 12:11:09 EST From: "KEN SARGENT" Subject: Re: COZY: aileron cut out more suggestions: if you have an air compressor - an air driven saws-all (J__ saw is politically incorrect) set to a short motion with a metal cutting fine tooth blade. Hold at a shallow angle. Tape to keep the saw base from vibrating into glass. Setup a fence an you will cut as fast and clean and straight as you want. I see craftsman trim FRP parts all day long with this tool, gliding effortlessly around the edge of molds. Hold the part down firm. Good for rough sculpting foam also. Ken Sargent #555 Chap 5-8. ______________________________ Reply Separator _________________________________ Subject: COZY: aileron cut out Author: gmellen@juno.com at disney-wdw-internet Date: 5/12/97 11:00 PM For cutting out my ailerons I purchased a razor back saw at a local hobby shop. Worked great and I only spent a couple of bucks on the thing. I used it as Marc described the hacksaw blade and with its stiff back I got nice straight cuts. George Mellen Subject: COZY: Strobe / Nav light wiring From: mbeduhn@juno.com (Mark W Beduhn) Date: Thu, 15 May 1997 10:45:34 EDT I am installing the strobe/nav lights in the wing tips and am not sure how to get the wires from the wing to the inside of the firewall (where the power supply is). Options that I can see: 1) Drill holes in the rear side of the spar near the firewall. 2) Drill holes in the ends of the spar (more difficult because of internal bulkheads). 3) Route the wires through the wire conduit on the lower part of the firewall. Obviously I will also have to install a plug(s) between the wing and the penetration point (no matter where it is). Any suggestions would be appreciated. Mark Beduhn Cozy IV N494CZ Date: Thu, 15 May 1997 08:09:29 -0700 From: Eric Westland Subject: Re: COZY: Strobe / Nav light wiring Mark, I did option #2. I drilled the holes in the center, there is enough room for the for the wire to make a "bend", so I did not concern myself with lining up the holes on the end of the spar and the conduit opening in the wing root. Besides, if you don't somewhat center the hole through the spar, you'll have a tough time working with the bolts for the wing inside the spar. Drilling the hole in the internal bulkheads was easy with a 1/4" drill extension, I don't think you will find it much of an obsticle. Jeff Russell gave me a great idea for conduit - K Mart shower rod covers. They are about $1 each, you'll need two. If I had it to do over again, I would have run another conduit through the strake leading edge, but I did not come upon that idea until they were done. It would have given me an addition route for running wires. -eric From: Marc J. Zeitlin Subject: COZY: Strobe / Nav light wiring (fwd) Date: Thu, 15 May 97 11:21:57 EDT Mark Beduhn asks; >Options that I can see: >1) Drill holes in the rear side of the spar near the firewall. >2) Drill holes in the ends of the spar (more difficult because of >internal bulkheads). >3) Route the wires through the wire conduit on the lower part of the >firewall. >From the archives (topics96/chap_19.txt), Jeff Russell wrote: >>We drill a 1" dia. hole in the end of the main spar between the two >>inside hard points as close to the inside aft shearweb. I also drilled >>a 1" hole at the lower aft corner of the inside bulkheads. Insert a >>piece of tubing (color shower curtain rod cover, Walmart or K-mart brand) >>for a electral conduit. If the conduit is mounted further away from the >>aft shearweb, it will be harder to install the wing washers and nuts on >>the 1/2" bolts. This sounded good to me. -- Marc J. Zeitlin Email: marcz@an.hp.com From: Roger Shell Subject: COZY: Electrical conduits in wing cores Date: Wed, 21 May 1997 13:18:30 -0600 I'm getting ready to cut the wing cores (chptr 19). I plan to route the = position/strobe light wiring through the core per the plans, but I can't = find where these wires go once they 'run into' the strake I would = prefer to route the wires through the leading edge of the strake = (conduit cut behind the shaped urethane foam) then into the fuselage and = forward to the instrument panel. Are the cutouts on the templates = forward enough to still do this and not be blocked by the main spar box? = Or, has anyone figured alternate locations for the conduits on the rib = templates to accomplish this? Also, will it be OK to route the VHF com = antenna wires through the same conduit without electronic interference = from the strobe? Thanks for the help. Roger Shell Cozy MKIV #357 From: "Dalrymple, Mark J" Subject: COZY: AILERON HINGE BONDOING TO AILERON - YEA RIGHT;0 Date: Fri, 23 May 97 15:53:00 PDT Hello Fellows Builders, how the heck did you guys get the bondo to stick to the aileron and the aileron hinge at the same time. Both have slick surface areas. How do you keep the hinge in spring contact to the aileron during bondo cure for hinge mount jigging. It seems to me that after cure and a little bit of movement the bondo breaks loose. Suggestions would be great. I plan to repeat the above process again tomorrow. Thanks for your support:) Mark Dalrymple Lost in the hinge mounting process... Date: Sat, 24 May 1997 17:34:05 -0400 From: Paul Burkhardt Subject: Re: COZY: Electrical conduits in wing cores Roger Shell wrote: > > > > Roger Shell > Cozy MKIV #357 The Plans version runs the electrical "stuff" through the spar. you must drill a hole into the spar (end ) once you have the wing mounted. I dont see why you cant run the conduit on the leading edge, however youll have to run your strobe wiring forward to the conduit, (assuming the power supply is mounted in the rear). Its my understanding that there is minimal interference with the strobe/wiring installation as per plans. If you havent drilled your hole in your spar yet for the wiring, it is possible to do afterwards( as I did) just use a long drill bit, and open it up with your rotary sander. - at arms length. I've heard that others have run the conduit on the leading edge, just have to adjust for the filler piece on the outboard strake. Paul Burkhardt From: Marc J. Zeitlin Subject: COZY: AILERON HINGE BONDOING TO AILERON Date: Sat, 24 May 97 23:34:03 EDT Mark Dalrymple writes: >how the heck did you guys get the bondo to stick to the aileron and the >aileron hinge at the same time. Both have slick surface areas. How do >you keep the hinge in spring contact to the aileron during bondo cure >for hinge mount jigging. I always rough up the hinges with 100 grit (and then clean them thoroughly). I also sanded the ailerons. The bondo stuck (not great, but it did), and I treated the setup VERY carefully until I could permanently affix them. I used some squishy foam to keep pressure on the hinges. There was some discussion about this topic previously - I'd suggest checking the chap_19.txt archives for both 1997 and 1996 - I'm sure you'll find something useful. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Mon, 26 May 1997 19:33:07 -0700 From: marcna Subject: COZY: Wing attaching alternative Hi folks, we just got finished mounting the wings and main spar to the fuselage and ended up with 0.0 incidence without using any additional washers and thought we'd pass along our method in case it helps someone else. The way we did this took a little more effort to begin with, but less when actually attaching the wings. This is what we did: First - To drill the holes for the bolts. We used saw horses and bondo'ed the main spar to that after leveling the spar. Then we placed the wings where they should be in relation to the spar (we're doing this in a hangar so we had forty feet of width to use). After minor adjustments we bondo'ed the wings to the spar and saw horses at an incidence of 0.0. Then we drilled the =BC" and then 5/8" holes for the bolts, separated the wings from the spar, epoxied in the bushings, reattached the wings with the bolts and let it dry (we smeared each bolt with grease to avoid epoxy sticking to it). Second - Attaching the spar to the fuselage. Next we took everything apart. Placed the spar in the fuselage and did a rough shim to place, which we totally ignored later. Then we re-attached the wings to the spar, on the fuselage. Then we spent an entire day aligning everything correctly, squaring everything with the canard, checking and re-checking the incidence until we had everything square, level and 0.0 incidence. = As a final check we did a visual check from about 20 feet in front of the plane to make sure everything looked right. Then we floxed the spar to the fuselage and lifted the trailing edge 0.3 degrees positive. After this dried and we removed the supports for the trailing edge, the wing was at 0.0 with the canard with no spacers. Our reasoning in doing this comes from building aerobatic R/C model airplanes. Our experience told us that the wing would drop after removing the supports. = Take it or leave it, this is a method that worked for us. When you're at a show with canards, take a look for yourself at the visual alignment of the canard to wing, and you'll be surprised at what you see. This method helps to achieve a perfect alignment. Marc and Nadine Parmelee Cozy Mark IV #425 Moving on to the strakes=85 Date: Sat, 31 May 1997 08:55:14 -0700 From: Mahan Subject: Re: COZY: AILERON BALANCE WEIGHTS Rego, why not get thin *steel* tubing instead of aluminum? Weighs more, and less potential corrosion problems. Fred in Florida Rego and Noleen Burger wrote: > > Hi All, > > Just started on the Ailerons - Took my steel rods down I bought 5 years > ago and Wham, they're rusted to bits, naturally they can be sandblasted > and coated but I thought a change is as good as a holiday, :-) > > What I want to do is flox in aluminium tubes of the same O.D. and insert > LEAD rods until the ailerons balance. > > Question: Is there a con to this like aluminium and lead causing an > electolytic reaction. I don't want to swap 1 corrosion problem for > another. > > Speedy responses please as I wish to get on with the job. > > Thanks All > > Rego Burger > CZ4 > #139 > P.E. > RSA Date: Sat, 31 May 1997 19:26:05 -0400 From: INFINITY Aerospace Subject: COZY: Re: Aileron Balance Weights Hi Rego and All, >What I want to do is flox in aluminium tubes of the same O.D. an= d insert LEAD rods until the ailerons balance.< We have used a steel tube that was just slightly larger in diamet= er than called out, and had a .25" ID, to balance ailerons since '83 - works= great. If you put too much, just drill it out - makes for very fine balance adjustment after painting. We drilled several 1.5" deep x .25" diameter holes down the seam = of steel blocks that matched perfectly, then poured molten lead in the holes= =2E = When the steel block halves were split, the lead slugs (pellets) came rig= ht out - they may need to be filled and ends squared off. They were pushed = in from each end of the steel tube from the center out until the ailerons balanced. We filled the tube to within about 2" of each end, then caped them off with flox. You'll be surprised how much lead it will take to balance the ailerons (we were). Infinity's Forever, JD Subject: Re: COZY: AILERON BALANCE WEIGHTS From: mbeduhn@juno.com (Mark W Beduhn) Date: Sun, 01 Jun 1997 22:07:59 EDT On Sat, 31 May 1997 01:16:37 -0700 Rego and Noleen Burger writes: >Hi All, > >Just started on the Ailerons - Took my steel rods down I bought 5 >years >ago and Wham, they're rusted to bits, naturally they can be >sandblasted >and coated but I thought a change is as good as a holiday, :-) > >What I want to do is flox in aluminium tubes of the same O.D. and >insert >LEAD rods until the ailerons balance. > >Question: Is there a con to this like aluminium and lead causing an >electolytic reaction. I don't want to swap 1 corrosion problem for >another. > If I were to do it over again, I would do exactly as you propose. It would be great to easily add weight to the ailerons to balance them. Mark Beduhn Cozy IV N494CZ From: Marc J. Zeitlin Subject: Re: COZY: Re: Aileron Balance Weights (fwd) Date: Tue, 3 Jun 97 16:22:26 EDT Howard Rogers writes: >...... I would certainly see nothing wrong with the lead >idea, as long as you kept extremely careful track of the total weight you >were adding, and if you couldn't do it within the plans maximum allowable, >you do what the plans tell you to do: Scrap those heavy parts, and build >new ones! The COZY MKIV plans (being derivatives of Rutan's plans) are also explicit in how much weight is OK to add, and how much you can sand off the aileron (See Chapter 19). As Howard (and the COZY plans) say, if you're out of those specs, chuck the aileron and build a new one, no matter how easy it is to make it balance by adding weight. -- Marc J. Zeitlin Email: marcz@an.hp.com by SERV05.SLAC.STANFORD.EDU (PMDF V5.1-7 #16063) with SMTP id <01IJMXX7TZZ6000LNR@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Tue, 3 Jun 1997 13:09:17 PDT Date: Tue, 03 Jun 1997 13:12:13 -0800 From: hrogers@SLAC.Stanford.edu (Howard Rogers) Subject: Re: COZY: Re: Aileron Balance Weights >Hi Rego and All, > > >What I want to do is flox in aluminium tubes of the same O.D. and >insert LEAD rods until the ailerons balance.< > > We have used a steel tube that was just slightly larger in diameter >than called out, and had a .25" ID, to balance ailerons since '83 - works >great. If you put too much, just drill it out - makes for very fine >balance adjustment after painting. > We drilled several 1.5" deep x .25" diameter holes down the seam of >steel blocks that matched perfectly, then poured molten lead in the holes. >When the steel block halves were split, the lead slugs (pellets) came right >out - they may need to be filled and ends squared off. They were pushed in >from each end of the steel tube from the center out until the ailerons >balanced. We filled the tube to within about 2" of each end, then caped >them off with flox. You'll be surprised how much lead it will take to >balance the ailerons (we were). > > >Infinity's Forever, > > JD While the above sounds very good, and full of advantages for trimming things up nicely, after the fact, it overlooks one important principal that Burt Rutan attempted to get accross quite clearly in the Long EZ plans. The whole balance thing is more complex than just getting the aileron to hang in the correct position, statically. If you build a wet, heavy aileron, you can make it hang by adding enough lead, steel, or whatever, but it isn't right, and it could potentially flutter. Rutan calls out specific specs, and if you can't get the things to hang straight with the max allowable weight added, it is most definitely NOT OK to simply add more weight till they do. I would certainly see nothing wrong with the lead idea, as long as you kept extremely careful track of the total weight you were adding, and if you couldn't do it within the plans maximum allowable, you do what the plans tell you to do: Scrap those heavy parts, and build new ones! --Howard Rogers, A&P 2005148 Date: Tue, 3 Jun 1997 21:19:33 -0400 From: INFINITY Aerospace Subject: COZY: Re: Aileron Balance Weights Hi Marc, Howard and All, >Howard wrote in reference to my post: While the above sounds very good, and full of advantages for trimming things up nicely, after the fact, it overlooks one important principal that Burt Rutan attempted to get across quite clearly in the Long EZ plans. T= he whole balance thing is more complex than just getting the aileron to hang= in the correct position, statically. If you build a wet, heavy aileron, you can make it hang by adding enough lead, steel, or whatever, but it isn't right, and it could potentially flutter. Rutan calls out specific specs, and if you can't get the things to hang straight with the max allowable weight added, it is most definitely NOT OK to simply add more weight till they do. I would certainly see nothing wrong with the lead idea, as long as you kept extremely careful track of the total weight you= were adding, and if you couldn't do it within the plans maximum allowable= , you do what the plans tell you to do: Scrap those heavy parts, and build= new ones!< >Marc wrote, also: >The COZY MK-IV plans (being derivatives of Rutan's plans) are, also, explicit in how much weight is OK to add, and how much you can sand= off the aileron (See Chapter 19). As Howard (and the COZY plans) say, if= you're out of those specs, chuck the aileron and build a new one, no matt= er how easy it is to make it balance by adding weight.< Concur with both. The purpose of the lead in tube aileron balanc= e idea is not to fix a poorly built overweight aileron, it is to more easil= y allow fine adjustment of your perfectly built light weight ailerons witho= ut having to sand paint off, or add paint, and try to blend both. Sorry I didn't make that clear before. Osmosis must not work through computers ;= -) =2E Infinity's Forever, JD From: Epplin_John_A@hpmail1.90.deere.com Date: Sun, 8 Jun 97 09:18:19 -0500 Subject: COZY: Aileron hinge I am getting ready to hinge the ailerons. I now see what all the discussion concerning the temporary bondo problem is about. Several recommendations of using spongy foam have been made. Are they talking about the foam used for upholstery? If so it makes sense. Thanks for some clarification John Epplin #467 From: Marc J. Zeitlin Subject: COZY: Aileron hinge (fwd) Date: Sun, 8 Jun 97 14:01:40 EDT John Epplin writes: >I am getting ready to hinge the ailerons. I now see what all the discussion >concerning the temporary bondo problem is about. Several recommendations of >using spongy foam have been made. Are they talking about the foam used for >upholstery? If so it makes sense. Yup. That's what I used. I had some pretty stiff stuff lying around, and it only took a couple of small bits to hold the hinge in place. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Sun, 08 Jun 1997 15:09:18 -0700 From: Michael Antares Subject: COZY: Cozy: Aileron hinges Not to be redundant (since I've thrown this idea to the group previously) but I do believe that the system I worked out has a lot of advantages. I'll provide some details in this posting. My method: the major issue I had with the method as outlined in the plans was trying to get everything aligned before the Bondo set up. My method gives you as much time as you want to take. You start out with the hinges mounted to the wing (per plans) and then secure the aileron in the proper position (I used 1x2's clamped top and bottom between wing and aileron). Here is where you can take all the time you want to get the aileron positioned precisely because you haven't applied any Bondo yet. So now the problem is that the hinge which is going to be fastened to the aileron is hanging down between the wing and the aileron--how to get it secured? So what I did first was to take a thin blade and push the hinge so that it is resting against the aileron; you can apply enough pressure to get a good seat and, if needed, you can either hold the hinge against the aileron using the blade while the Bondo sets up or place a weight against the blade which will hold the hinge in position. Having done this, now apply Bondo along the hinge line--I put little dabs on that portion of the hinge line (I'm talking about that part of the hinge which has the wire going through it) that mates with the aileron. I let the Bondo thoroughly cure and then VERY carefully removed the screws holding the hinges to the wing and VERY carefully removed the aileron--voila, the Bondo held and the hinges remained on the aileron. I then VERY carefully drilled two spotting holes through the hinge into the aileron, inserted rivets (unclinched) and drilled the remaining holes. You can then break the Bondo loose, spread the flox and remount the hinges. I ended up with the ailerons absolutely in alignment. I was actually quite amazed at how well the Bondo held considering that it was only attached to an area of the hinge about a 1/16 of an inch high. It is also quite easy to get the Bondo off of the hinge later. 6077 Old Redwood Highway Penngrove CA 94951 707.792.7971 Cozy#413 Finished through chap 14 except chap 13. Chaps 16 & 24 mostly finished. Now on chap 19 and 20. One wing/winglet finished, working on second. From: Ken Reiter Date: Tue, 17 Jun 97 11:08:23 CDT Subject: COZY: Ailron Wing Root Bearing Hello Guys, I have been trying to get Weldtech; but no luck so far. Does anyone else make the wing root bearing retro kit? Thank You, Ken Reiter Plano, TX Date: Wed, 18 Jun 1997 22:03:49 -0500 From: skorija@ic.net (Skorija) Subject: COZY: lightening Stupid prebuild question - anyone using a diferent foam than styrofoam or sandwiching various materials for the wing?? I am not planning on hot wiring, so the burning problem is gone. Mike S maker of wood dust and shavings, soon to be maker of foam and fiberglass dust #591 Skorija @ic.net Date: Fri, 20 Jun 1997 10:38:52 -0500 From: Bulent Aliev Organization: American Yacht Sales, Inc. Subject: Re: COZY: lightening My friend used the pink construction foam on his canard and winglets. It cuts better with the hot wire but does not send well at all. It is not worth the trouble. Stick with the blue stuff. Buly Date: Fri, 18 Jul 1997 10:43:55 -0700 From: Rego and Noleen Burger Organization: R.N.B. Enterprises Subject: COZY: Aileron Balance Weights Aileron balance weights: I've done them....the other way....they work! Thanks to the group who helped answer a few questions on the idea I had to do this, knowing others have done it does make it more comfortable to try something a little new. I ended up using copper tube ( low corrosive properties ) in the leading edge. This is filled with lead "rods" of 2" I found in the unpainted state it needs about 40" of the 60+ to level, so I have 20+" to balance the paint with! Making the lead: I found getting the lead out of the steel "mould" (holes drilled in block) a little labour intensive. If you did not have a raised lump to grab on I could'nt get it out. What I suggest is clamping two bite of aluminium in a vice and drilling the holes in the center seam/split. These two halves can be held together with G-clamps, after pouring lead just split open and pop goes your "rods" My weights cost me less than a dollar (R 4,50) to cast and guess it's far cheaper than the steel rods I bought previously, what do I do with them now? --=20 R=E9go Burger Cozy Mk4 # 139 Port Elizabeth RSA http://www.home.intekom.com/glen/rnb.htm Date: Wed, 23 Jul 1997 09:35:42 +0200 From: Rego Burger Subject: COZY: Aileron Travel I flipped through the plans without much success late last night. Maybe that's the problem. My Question? How much up and down movement on the aileron is acceptable? I find the Rudder, and elevator....typical not what I want at the time. Pg/chp. ref. will be fine. I find the bolt through the torque tube catching...not healthy! Thanks Rego Burger Port Elizabeth RSA ( Rep. South Africa ) cozy Mk 4 # 139 http://www.home.intekom.com/glen/rnb.htm 041-386113 (work) Date: Wed, 23 Jul 1997 09:47:54 +0200 From: Rego Burger Subject: COZY: Aileron Hinge Mounting Something small - hope it can help someone, worked for me. You've bolted the hinges onto the wing and wish to attach the aileron to the loose hinges. Many use bondo but I opted for 5 min epoxy mixed with micro to make it break off easy. 40-50% Micro. After mixing wait 2 min before applying a few dabs to the hinge surface. Now how do you keep them up? I rolled some 3/8" foam ( sponge ) into a "swissroll" slip under each hinge and presto the hinge lifts up. Now just hold the aileron down for 3min in it's exact place. The sponge applies pressure from the bottom until dry. Unscrew hinges (when dry), drill holes for rivets. Pop off hinge and clear glue dabs off etc. I had to do this as I was working alone. Rego Burger Port Elizabeth RSA ( Rep. South Africa ) cozy Mk 4 # 139 http://www.home.intekom.com/glen/rnb.htm 041-386113 (work) Date: Wed, 23 Jul 1997 09:58:22 +0200 From: Rego Burger Subject: COZY: Mistakes As asked before to encourage folks who may struggle, here are a few I made. WING/AILERON CONSTRUCTION When building the wing the plans call for strips of peel-ply under the skin to facilitate the manufacture of the Aileron trailing edge area. No problem. However when the Aileron must get a bid layup over the balance weight you need to roughen up a 1" area for adhesion. To make this easy I suggest placing a strip of peel-ply on the wing/aileron skins during construction. this should save you a little time later. Just realise the strip on the aileron will be on the aileron side of the line. Top/bottom. Good luck. Learning from other's mistakes is cheaper! Rego Burger Port Elizabeth RSA ( Rep. South Africa ) cozy Mk 4 # 139 http://www.home.intekom.com/glen/rnb.htm 041-386113 (work) From: Marc J. Zeitlin Subject: COZY: Aileron Travel (fwd) Date: Wed, 23 Jul 97 9:57:59 EDT Rego Burger wrote: >How much up and down movement on the aileron is acceptable? >Pg/chp. ref. will be fine. Don't have the page/chapter # since I'm at work here, but it's GOT to be chapter 19. I remember measuring the aileron motion with a inclinometer, and my brain is telling me it was +/- 20 degrees nominal. I won't vouch for that though - someone please back this up. I'll try to check tonight when I get home. >I find the bolt through the torque tube catching...not healthy! Yes, I found this too - I had to clear away a good bit of foam inside the universal joint hollow area just inboard of the aileron, and then reglass with one BID. Not a big deal. I made sure I had at least 1/2" of clearance all around. -- Marc J. Zeitlin Email: marcz@an.hp.com Subject: Re: COZY: Aileron Travel (fwd) Date: Wed, 23 Jul 1997 11:37:46 -0400 (EDT) From: "Randy Smith" Marc Zeitlin wrote: > Rego Burger wrote: > > >How much up and down movement on the aileron is acceptable? > >Pg/chp. ref. will be fine. > > Don't have the page/chapter # since I'm at work here, but it's GOT to be > chapter 19. I remember measuring the aileron motion with a inclinometer, > and my brain is telling me it was +/- 20 degrees nominal. I won't vouch > for that though - someone please back this up. I'll try to check tonight > when I get home. Marc is correct. It is in chap. 19, page 9, step 11 specifies an aileron up travel of 20 degrees. It makes no reference to down travel. Unless the sentence "Position the stop bolt to stop CS128 at 20 degrees travel from the neutral position shown." means +-20 degrees from neutral. > -- > Marc J. Zeitlin Email: marcz@an.hp.com > -Randy --* --- -* **-* *-** -*-- -* Watch this space for COZY progress |Cozy MkIV| NCR General Purpose Computing Randy.Smith@ColumbiaSC.NCR.COM |---( )---| Global Support Center Voice 803-939-7648, V+ 633-7648 ___o/o\o___ West Columbia, SC 29170 "I am the way, the truth, and the life..." -JC From: Marc J. Zeitlin Subject: Re: COZY: Aileron Travel (fwd) Date: Wed, 23 Jul 97 13:23:58 EDT Randy Smith wrote; >Marc is correct. It is in chap. 19, page 9, step 11 specifies an aileron >up travel of 20 degrees. It makes no reference to down travel. Unless >the sentence "Position the stop bolt to stop CS128 at 20 degrees travel from >the neutral position shown." means +-20 degrees from neutral. Since the ailerons are connected and the deflection of one is approximately equal to the opposite deflection of the other, having a stop bolt for each aileron limit travel to 20 degrees will ensure that it's +/- 20 degrees for each aileron. -- Marc J. Zeitlin Email: marcz@an.hp.com From: "mel" Subject: Re: COZY:wing drilling Date: Thu, 24 Jul 1997 23:25:53 -0400 don't replace the 1/4" bit with a longer 1/4" bit. replace it with a 1/4" piece of round stock, that way it doesn't tend to enlongate the starter hole as it works it's way thru, so the hole comes out much truer. norm & monda cozy IV #202 ---------- > From: George J Mellen Jr. > To: cozy_builders@hpwarhw.an.hp.com > Subject: COZY:wing drilling > Date: Thursday, July 24, 1997 3:06 PM > > >Some time ago someone wrote about using a hole saw instead of spotfacer > >to drill the wing bolt holes. Sounded like a good idea to me, grind > >some of the set off of the hole saw so it cut pretty well on size if I > >remember right. Should produce a lot less heat etc and be less likely > >to damage anything in the process. > > I did this with my wings, and the hole saw is not as precise as the spot > facing tool. The holes are a fraction over size and when I bonded the > steel inserts into the holes and then went to bolt the wings to the spar > a couple of the holes did not quite line up !!! I was however able to > fix this, by knocking the inserts back out and floxing the inserts back > in while the wing was bolted to the spar. > I tried at first with a borrowed spot facing tool ( that had already > built two airplanes) and got nowhere fast. The hole saw zipped right > through. > > >My question: I looked at several lumber yards and hardware stores and > >cannot fine a 5/8 hole saw, where do I get one? > > I found mine at Builders Square, I believe it was made by Dewalt. I then > took the 1/4" bit out of the arbor that came with it and replaced it with > a 1/4" bit that was about 12" long . Worked great. > > George Mellen gmellen@juno.com Date: Fri, 22 Aug 1997 17:13:29 -0400 From: "Steven D. Sharp" Organization: I'm organized - if I can only find it Subject: COZY: Teflon hinge pins McMaster Carr has teflon spaghetti tubing 0.090 O.D. X 0.066 I.D for approximately $0.18/ foot minimum 5' lengths. Part number 5335K17 Page 45 Catalog 103. Run a piece of 1/16 stainless steel TIG wire through it (I used 420 but 300 series should be okay also) and volia - teflon covered hinge pins. McMaster Carr accepts MC, VISA, AE, and they have a web site also. TIG wire? Try the local welding shops & supply houses - get a pound and share the extra (and there will be a bunch) with your flying buddies. Just trying to reduce the cost of building & flying. Steve Sharp cozyiii@earthlink.net From: "Jim White" Subject: Fw: Aileron Wing Root Bearing Solved Date: Thu, 28 Aug 1997 16:58:32 -0700 Marc, Here is a note I posted to the canard aviator list.. There may be some people on the Cozy list that are also interested in this bearing. Could you please post this to them for me? Thanks, Jim White ---------- > From: Jim White > To: Canard Aviators > Cc: Jim White > Subject: Aileron Wing Root Bearing Solved > Date: Monday, August 25, 1997 10:33 AM > > I believe I have finally found the near perfect bearing for the aileron > torque tube bearing at the wing root. (A perfect bearing would be free :=) > After extensive searching of various bearing manufacturers, I have found a > spherical bearing that provides, rolling, sliding, and pivoting action > needed for this bearing station. It is high quality, light weight (one > ounce), durable, and retrofittable in existing canard aircraft. The > bearing is manufactured by Rexnord Corp., a company that makes general > purpose and aerospace bearings. > The bearing construction is as follows: > * Composite bearing housing with spherical teflon bearing surface on the > inside diameter, 1.25" OD, 1" ball ID, 0.6" width. > ** Stainless steel spherical ball. 1" OD, and 0.75" ID. > *** Composite journal bearing with 0.75" OD and 0.625" ID with teflon > bearing surface. > > The composite journal bearing is press fit inside the stainless steel > spherical bearing. All sliding surfaces are metal to teflon bonded to > composite. EZ installation consists of boring your existing 0.625" wing > root phenolic bearing hole out to 1.25". Flox the new bearing in its place > and you're done. In the sample I floxed in place, the composite material > appears to bound very well to the phenolic block. I plan on sending the > bearing to Nat Puffer for his thoughts. As a mechanical engineer, I see no > reason why it shouldn't work. > The bearings are relatively expensive at $65 each from the factory. We may > be able to beat this price if we can get together an order of 100 or more > (50 canard aircraft). E-mail me if you are interested in purchasing a set > of bearings for your aircraft. > Build it right or don't buiild it at all, > Jim White > N44QT > jimwhi@mindspring.com From: "Marc J. Zeitlin" Subject: COZY: Fw: Aileron Wing Root Bearing Solved (fwd) Date: Sun, 31 Aug 97 21:40:24 EDT Marc, Here is a note I posted to the canard aviator list.. There may be some people on the Cozy list that are also interested in this bearing. Could you please post this to them for me? Thanks, Jim White ---------- > From: Jim White > To: Canard Aviators > Cc: Jim White > Subject: Aileron Wing Root Bearing Solved > Date: Monday, August 25, 1997 10:33 AM > > I believe I have finally found the near perfect bearing for the aileron > torque tube bearing at the wing root. (A perfect bearing would be free :=) > After extensive searching of various bearing manufacturers, I have found a > spherical bearing that provides, rolling, sliding, and pivoting action > needed for this bearing station. It is high quality, light weight (one > ounce), durable, and retrofittable in existing canard aircraft. The > bearing is manufactured by Rexnord Corp., a company that makes general > purpose and aerospace bearings. > The bearing construction is as follows: > * Composite bearing housing with spherical teflon bearing surface on the > inside diameter, 1.25" OD, 1" ball ID, 0.6" width. > ** Stainless steel spherical ball. 1" OD, and 0.75" ID. > *** Composite journal bearing with 0.75" OD and 0.625" ID with teflon > bearing surface. > > The composite journal bearing is press fit inside the stainless steel > spherical bearing. All sliding surfaces are metal to teflon bonded to > composite. EZ installation consists of boring your existing 0.625" wing > root phenolic bearing hole out to 1.25". Flox the new bearing in its place > and you're done. In the sample I floxed in place, the composite material > appears to bound very well to the phenolic block. I plan on sending the > bearing to Nat Puffer for his thoughts. As a mechanical engineer, I see no > reason why it shouldn't work. > The bearings are relatively expensive at $65 each from the factory. We may > be able to beat this price if we can get together an order of 100 or more > (50 canard aircraft). E-mail me if you are interested in purchasing a set > of bearings for your aircraft. > Build it right or don't buiild it at all, > Jim White > N44QT > jimwhi@mindspring.com -- ______________________________________________________________________ / Marc J. Zeitlin Email: marcz@an.hp.com \ | Patient Monitoring Division (PMD) HP Telnet: 1-659-3421 | | Hewlett Packard Voice: 1-508-659-3421 | | 3000 Minuteman Road Fax: 1-508-685-3577 | | Andover, MA 01810-1099 | | Mail Stop: MS-460 WWW: http://www.ultranet.com/~marcz/ | |_____________________ http://www-msy-me.an.hp.com/~marcz/ | | (c) copyright 1997 \ (HP Internal ONLY) | \______________________\_______________________________________________/ From: ponciroli@postoffice.worldnet.att.net Date: Sun, 7 Sep 1997 10:45:50 -0500 Subject: COZY: Wing alignment Folks - I need help. I have F1, F2, and F3 in the jigs vertically. I realize that the plans say that there is some twist in the wing, however when sighting from the wing tip my sheer web is not straight. It shows that if it were in the horizontal it would droop about one inch from the middle of the wing to the tip. I believe that it should be symetrically striaght. I have called Nat and he is on vacation. Can any one talk to this problem? Don Ponciroli (860) 464-1158 Date: Tue, 16 Sep 1997 19:33:02 -0400 From: Neil Clayton Subject: COZY: Aileron shaft bearings I've been battling with the design of these wing root bearings; (I hate the phenolic arrangement in the plans) After considering ball (or roller) bearings, I went back to plain journal bearings because of weight, added complexity, and the difficulty of "housing" a ball bearing unit. I made up a few plain journals from different materials and finally settled on Teflon. After a night in the freezer to see what happens to the steel/teflon combination at low temps (=hi-altitudes) I decided I'm onto a solution. The friction increases but the journal remained free to rotate. If no oil is added (a no-no with teflon/steel anyway) there's little chance of the assembly freezing). I plan to flox(?) the journal through an alum plate and screw/wire the plate to nutplates buried around the periphery of the aileron shaft hole in the wing root - that way the entire thing is removable, and alignable with the C/L of the shaft. Anyone got any critiques of this arrangement? Thx neil From: JQUESTCOZY@aol.com Date: Tue, 16 Sep 1997 20:52:27 -0400 (EDT) Subject: Re: COZY: Aileron shaft bearings In a message dated 97-09-16 19:35:51 EDT, harvey3@worldnet.att.net writes: << 've been battling with the design of these wing root bearings; (I hate the phenolic arrangement in the plans) >> Neil, I'm working on the wing root bearing also and was thinking of using different material also. My local plastics company recommended some stuff called UHMW ( ultra high molecular weight) I told them it was for a slow turning shaft bearing (did not tell him airplane) and asked about Delrin also. He replied that the UHMW would hold up better than the Delrin on wear, however the Delrin held it's tolerances better as temperature varies. Now I don't know how much the UHMW varies with temperature changes.. The stuff I got is 1/4 thick and looks just like your normal white teflon. The torque tube seems to operate much smoother on the UHMW vs. phenolic. Anyhow, my question to you guys is: Does anybody have any experiance using the UHMW on their torque tubes? Did it hold up better than the phenolic? Also I noticed that the torque tube is not perpendicular to the wing root surface that the bearing material will mount to. Is this what others have found? Helpful hint; I made a slave bearing out of plexiglass (1/4 inch thick, same as dim. as phenolic per plans) for a fit check. This allows you to "see" through while positioning and is helpful in fine tuning shape of whatever material you end up using. Thanks John Wilemski cozy #227 ch.19 (one wing done almost done) From: Marc J. Zeitlin Subject: Re: COZY: Aileron shaft bearings (fwd) Date: Wed, 17 Sep 97 9:09:38 EDT John Wilemski; >Does anybody have any experiance using the UHMW on their torque tubes? Did >it hold up better than the phenolic? We had this exact discussion in '96 and again earlier this year. Check the archives for "chap_19.txt" for both years to review the discussions. >Also I noticed that the torque tube is not perpendicular to the wing root >surface that the bearing material will mount to. Is this what others have >found? Yes, but it's not off by much. Making the hole in the bearing a few thousandths oversize allows the tube to rotate freely in the hole. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Wed, 17 Sep 1997 09:27:12 -0500 From: Bulent Subject: Re: COZY: Aileron shaft bearings I build my controls instead with the standard phenolic plate and steel tube, with 1/4" Nylon plate and Delrin rod. Here in FL the steel tube rusts in hours and you can hear the rusty steel grinding inside the phenolic. The Nylon to Delrin arangement is self lubricating, corosion resistant and strong enough for this purpose Wicks sells the Nylon Plate and the plastics shops have the Delrin rod in all sizes. Bulent From: cdenk@ix.netcom.com Date: Wed, 17 Sep 1997 19:17:56 -0500 (CDT) Subject: Re: COZY: Aileron shaft bearings On 09/17/97 09:27:12 you wrote: > >I build my controls instead with the standard phenolic plate and steel >tube, with 1/4" Nylon plate and Delrin rod. Here in FL the steel tube >rusts in hours and you can hear the rusty steel grinding inside the >phenolic. The Nylon to Delrin arangement is self lubricating, corosion >resistant and strong enough for this purpose Wicks sells the Nylon Plate >and the plastics shops have the Delrin rod in all sizes. > >Bulent > > I either have stainless spherical bearings, or stainless tubing inside plastic (I don't remember the variety, but they are industial plastic type) bushings, or ball bearings. I assume the delrin slips inside the torque tube, and the nylon bushing rides around the delrin. I would be concerned about twisting off the delrin. Its possible (in particular in an emergency) to exert considerable torque. I believe I would stick closer to the drawings. From: "Jim White" Subject: [canard-aviators] Re: Aileron bearings Date: Mon, 22 Sep 1997 08:46:47 -0700 Subject: [canard-aviators] [The Canard Aviators's Mailing list] > Jim, did you ever compile enough people to order a quantity of those > bearings? Let me know when you do... Thanks John DeStories. I compiled a list of about 20 builders so far. I sent the bearing to Nat Puffer (original Cozy III & IV designer) and Vance Atkinson for their thoughts. Both thought it looked fine. It turns out, both Nat and Vance have some sort of spherical bearing at their wing root location. Neither one could remember where they got theirs or who the manufacturer is. I submitted a letter to Nat who said he would run it in the Cozy Newsletter. The letter asks if any of the Cozy builders know of a cheaper bearing that does what the composite bearing that I found does. I doubt that anyone has one of higher quality than the aerospace bearing made by Rexnord Corp., but there may be bearings out there that do essentially the same thing for a lot less money. Below is a copy of the letter I sent Nat. Dear Nat, I have been looking for a lightweight, spherical bearing to replace the standard phenolic bearing at the wing root. Based on conversations with numerous canard fliers, the phenolic bearing at this location does not hold up very well over time because of the motion that the aileron torque tube makes. I found a composite and stainless steel bearing that provides the sliding, rolling, and pivoting motion needed at this position. It only weighs an once and is easily installed in an existing or new Cozy. This bearing appears perfect in every way except one, each one costs $70! A bulk purchase of more than 100 bearings only brings the price down to about $65 each. The bearing consists of a stainless steel ball riding on a Teflon coated surface of an outer composite housing. Pressed inside the stainless steel ball is a composite journal bearing with a Teflon coated inside diameter. It is made by Rexnord Corp. , phone 630-969-1770. Specify Duralon self-aligning bearing, part number 801-12-20-1 and journal bearing, part number 701-00010-020. Also specify that the journal bearing be pressed into the spherical bearing by the manufacturer. Installation consists of boring the phenolic bearing hole out to 1.25" and floxing the new bearing inside the 1.25" opening. This bearing is of exceptional quality and I am confident it will work quite well in my Cozy. However, if there is anyone out there in Cozyland who has found an alternative lightweight and less expensive spherical bearing for this location, I'd like to hear from them. If I find out anything, I will pass it on to everyone else. My e-mail address is jimwhi@mindspring.com and my phone number is 503-690-8173. Thanks, Jim White ---------------------------------------------------------------------- To remove yourself from this list, send email to: majordomo@canard.com and put the following as the very first thing in your message body: unsubscribe canard-aviators you@youremail.com If you have problems, please email support@canard.com For more information visit: http://www.canard.com Date: Mon, 22 Sep 1997 17:10:48 -0400 (EDT) From: Nigel Field Subject: COZY: Re: Aileron bearings At 08:46 AM 9/22/97 -0700, "Jim White" wrote: I >submitted a letter to Nat who said he would run it in the Cozy Newsletter. >The letter asks if any of the Cozy builders know of a cheaper bearing that >does what the composite bearing that I found does. I doubt that anyone has >one of higher quality than the aerospace bearing made by Rexnord Corp., but >there may be bearings out there that do essentially the same thing for a >lot less money. Hi Jim, All, I posted this some time back but throw it out again. On my aileron torque tubes I used self aligning sperical bearings made by Ringball part # "B 10 L" about $9.00 each available at any good bearing supplier. Machined up alluminum top hat shaped cups to hold them to the phenolic plates shown in the plans with 3 10-32 allen head machine screws. Works great in the shop but not flight tested yet. They appear to be good quality and certainly cheaper. Nigel Field MK III under way again Date: Wed, 24 Sep 1997 10:16:45 -0500 From: Bulent Subject: COZY: BEARINGS H, All, after reading all the mail about aileron bearings and the $50-$60 price tags, I found in the granger catalog abearing that may be a cheaper alternative. It is just a suggestion. Please do not whip me if you do not like it. On page 362 Stock #1F674. It is a UHMW (Ultra-high Molecular Weght Polyethylene) Washdown Pressed stainless steel housing-self aligning bearing. Comes in 1/2"/ 5/8" / 3/4" and 1" bore and costs $7.06. The housing has two bolt mounting holes. It is rated -60 to +180 F. Bulent CZ IV #66 From: AlWick@aol.com Date: Fri, 26 Sep 1997 19:49:42 -0400 (EDT) Subject: COZY: alternate method to test fuel tank Recommend you find some old person and steal their blood pressure unit. You can let them keep all but the gage and bulb. Just happened across this method to test my strakes. It works quite well. Hose from vent goes to 'T' , one side to gage, other to bulb. It only takes 30 pumps to get pressure to 20 mm hg. Unfortunately I didn't need to go to higher pressure. Found leak in each tank. As expected, leak at top corner near end of spar. Also found small leak in middle of one sump. Just brushed on soapy water and looked for bubbles. Easy to fix, apply epoxy, suck on vent for a few seconds, let cure vented. Sure appreciate all of the suggestions others have offered. Great way to learn. FWIW -al Date: Fri, 26 Sep 1997 22:15:48 -0400 From: "Calvin N. Hobbs" Organization: First Church of Yoda, Master of Jedi Knighthood, Inc. Subject: COZY: In search of the perfect core Dear Fellow Aviation Aspirants, If you could give three tips to cut perfect canard and wing cores What would they be? 1. 2. 3. Date: Sat, 27 Sep 1997 15:16:31 +0200 From: Jean-Jacques CLAUS Subject: Re: COZY: In search of the perfect core Ce message est en plusieurs parties sous format MIME. --------------7A5F78111746 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Calvin N. Hobbs wrote: > > Dear Fellow Aviation Aspirants, > > If you could give three tips to cut perfect canard and wing cores > > What would they be? > > 1.It isn't possible to have perfect ( without anything ) cores for the wing because each template have a different size than other. Dont' be worry by all the little difference that you will see ( you can sand or fill as you need ). For layup the skin you'll add slurry + 2 or 3 plies of glass. After that you can't see them. Later there will be the finishing time with filler and paint. For the canard, the templates are the same both side, so the result can be perfect. On mine it was. > > 2.If you want perfect spar holes on the wing cores you can made holes wing templates like these of the canard ( see chap.10 ). In this case the result is perfect ! > > 3.If you follow the plan's instruction about hot wire, there will be no problems. Personnaly, i was afraid before the hot wire process. Now i like it. Hope to help you, --------------7A5F78111746 Content-Type: text/plain; charset=us-ascii; name="signature.txt" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="signature.txt" +-------------------------------------------------------+ !Jean-Jacques CLAUS ! !Aix-en-Provence - FRANCE ! ! ! !COSY CLASSIC #CC1056 ! ! mailto:fpjjc@hol.fr ! ! mailto:Jclaus@hol.fr ! ! ! !Visit and send your pictures to ! ! ! ! The CANARD BUILDERS WEB GALLERY ! ! http://www.mygale.org/05/jclaus/ ! ! ! +-------------------------------------------------------+ --------------7A5F78111746-- Date: Sun, 28 Sep 1997 14:14:55 -0500 (CDT) From: cdenk@ix.netcom.com Subject: Re: COZY: In search of the perfect core In cutting cores, always use a templete, it doesn't take long to make a set. for straight line I commonly use a set of framing squares, and 2 clamps, but be sure the 2 squares are not electrically connected by the clamps. Yes you can fill mistakes, but remember that costs precious weight. It may be better to hot wire a rectangle, and a thin glue line of slurry to repair. Date: Mon, 29 Sep 1997 09:38:33 -0500 From: Bulent Subject: COZY: Re: [canard-aviators] (no subject) 1. Use oversize templates for the hot wire 2. Make corect size templates of aluminum 3. Sand down to correct size with long sanding block(5') Bulent (954) 613-8117 off From: cdenk@ix.netcom.com Date: Mon, 29 Sep 1997 16:33:40 -0500 (CDT) Subject: Re: COZY: Re: [canard-aviators] Oversize hotwire templates Remember that every stroke of 80 grit plus/minus sandpaper across the thin edges of the aluminum templates will remove precious aluminum destroying the contour. Carl Denk: "cdenk@ix.netcom.com" Date: Tue, 30 Sep 1997 08:27:03 +0200 From: Rego Burger Subject: COZY: Chapter 19 layups on wing. I was curious about the layups on the wings, the little V and the square pad. Now that Nat has e-mail it's nice chatting to him too! I felt there may be folks in the group who may be interested. Naturally if every design consideration was writen in the plans they would be bigger and more expensive. Maybe Nat can feature the odd story in the Newsletter on design considerations. Nat Wrote: >>Rego, The V-shaped layup over the wing attach points are reinforcements to help collect the load and transfer it to the center spar. In Chap. 19, p.6, Fig. 32 the 2"wide layup across the corner is at a point of stress concentration, and your paint might crack their if you leave it out. The 12" layup in the valley is where the maximum bending and drag (pushing backwards) loads are. The drag loads are compressive loads which tend to buckle the skin. A little extra skin thickness at this point provides an extra safety factor when exceeding Vne. Regards, Nat<<<<<<< Naturally you experts know this but YUD's like me need to learn as much as possible. (Young Upcoming Designers) Happy building. Rego Burger CZ4#139 Date: Thu, 16 Oct 1997 21:50:46 -0400 From: Ian Douglas Organization: WTC Subject: COZY: Chapter 19 page 4 Hi there, Anyone know the drawing number that calls out LWA6 and LWA4 details? We are ready to do the shear web on the wing but don't know how big these are supposed to be. I want to make sure that the butt joint to W18 is correct and that the radii for the corners are correct. -- Ian D.S. Douglas MK0069 MK0626 From: Marc J. Zeitlin Subject: COZY: Chapter 19 page 4 (fwd) Date: Fri, 17 Oct 97 9:11:06 EDT Ian Douglas asks a non-electrically related question that has nothing to do with pre-nuptial agreements, with no unwarranted fawning to the list administrator :-) : >Anyone know the drawing number that calls out LWA6 and LWA4 details? We >are ready to do the shear web on the wing but don't know how big these >are supposed to be. I want to make sure that the butt joint to W18 is >correct and that the radii for the corners are correct. As I look at Figure 16 on the page to which you refer (chapter 19 - page 4) I see dimensions for both LWA4 (1.5" x 2") and LWA6 (2.3" x 2"). Both of them need to have one corner radiused so that the glass can wrap around the corner. The actual radius is not critical - 1/8" to 1/4" radius would be fine - just so that the glass will wrap and not pick up. If you look at chapter 14, page 7, there is a diagram of LWA2's and LWA4's with dimensions and radii. Nat calls out an "approx. 0.2" radius". -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Tue, 18 Nov 1997 10:14:34 -0600 From: Chris Anderson Subject: COZY: Is the wing the same? Is the cozy wing the same as the LE? Could I use cores cut for a LE? Just wonderin =-=-=-=-=-=-=-=- Chris Anderson andersoc@idcnet.com You can't save everyone folks, just try not to be living next door when they go off... Dennis Miller From: Marc J. Zeitlin Subject: COZY: Is the wing the same? (fwd) Date: Tue, 18 Nov 97 11:53:12 EST Chris Anderson writes; >Is the cozy wing the same as the LE? Could I use cores cut for a LE? For a COZY MKIV, the answer is NO. The airfoil is the same at the root and the tip, but the wing is longer, so the cores are NOT identical. I don't know if the COZY III is the same as the L.E. or not. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Tue, 18 Nov 1997 22:34:43 +0200 From: Rego and Noleen Burger Organization: R.N.B. Enterprises Subject: Re: COZY: Is the wing the same? NO.....NO! It is Not the same...be careful. The airfoil is 99% the same root and tips. The layups are slightly different. The Spar Caps are different thicknesses. etc...etc. Even the attachment points are different. When Nat started with the three placer he modified them to the requirements need for strength and so too with the 4 placer..changes were made to make them stronger. The Long-Eze wings are suitable for any two seat redesign attempt, at your own risk naturally. Rego Burger CZ4#139 RSA http://home.intekom.com/glen/rnb.htm Date: Tue, 18 Nov 1997 22:32:28 -0500 From: "Jeff S. Russell http://www.AeroCad.com" Organization: AeroCad Inc. Subject: Re: COZY: Is the wing the same? Chris Anderson wrote: > > Is the cozy wing the same as the LE? Could I use cores cut for a LE? > Just wonderin Chris, You could use the Long-EZ hot wired cores but the spar caps will need to be deeper per the Cozy 3 plans. The Spar caps were thicker and the sher web was also added to. This would not be a hard change to convert the foam cores if you compare notes on this. Hope you have both plans. The RAF CD-Rom does not include the Cozy plans but does have all the Burt Rutan plans on them giving the spar cap and sher web layups on the EZ. Marc Z wrote: < For a COZY MKIV, the answer is NO. The airfoil is the same at the root and the tip, but the wing is longer, so the cores are NOT identical. I don't know if the COZY III is the same as the L.E. or not.> Rego Burger wrote: NO.....NO! It is Not the same...be careful. The attachment points are the same as the Long-EZ. Same metal, Same spacing, Same plies of glass. The Cozy MKIV has a attach point different then the Long-EZ. -- Jeff Russell/AeroCad Inc. E-mail: Jeff@aerocad.com P.O. Box 7307 Port St. Lucie FL. 34985 Shop# 561-460-8020 Home# 561-343-7366 Composite workshop info: http://www.Sportair.com Date: Wed, 19 Nov 1997 09:26:24 -0500 From: Ian Douglas Organization: WTC Subject: COZY: Wing cores Hi All, It would appear that there has been some sort of error during the cutting of the foam blocks for my wings. After I place them in the jigs the angle between FC1 and FC2 is so bad that there is a 1" space along the TE. I have measured the lengths and am now sure that either the FC1 or rest of wing (FC2 FC3 FC4 and FC5) angle is wrong (have to go buy a protractor). I am guessing that if the angle in FC1 through FC4 is wrong I will have to cut new cores as the airfoil would then be the wrong shape (the whole foil will be compressed). Did anyone else run into this or am I the first? There was a wedge glued between FC1 and FC2, but that causes the length along the TE to be 1" too long (I have cut it out). Hopefully it is FC1 so all I will have to do is re-hotwire that single piece. Hey Jeff, looks like I may want wing cores with the canard and winglettes (now you now what is holding things up)! I have sent Marc a DXF file of the wing (was taking too long to do measurements from plans) and if anyone would like I also have a GIF file that is 101K for those of you without CAD software. -- Ian D.S. Douglas MK0069 From: Fritzx2@aol.com Date: Sun, 30 Nov 1997 17:29:16 -0500 (EST) Subject: COZY: Aileron linkage For those who have finished their wings and ailerons, does the steel tube CS152 that rides in the phenolic block move axially (outboard) slightly when the aileron is deflected? It looks like it would have to since the wing aileron torque tube, CS151, that deflects the aileron is not coaxial with the aileron hinge pins. I was just reading ahead in preperation to order some Brock parts and came across this linkage problem where is seems like the two non-coaxially rotating parts would require either the driving linkage on one side of the universal joint or the aileron on the other side to move axially to accomodate the needed one extra degree of freedom. John Fritz fritzx2@aol.com From: Marc J. Zeitlin Subject: COZY: Aileron linkage (fwd) Date: Mon, 1 Dec 97 13:53:40 EST John Fritz asks; >does the steel tube CS152 that rides in the phenolic block >move axially (outboard) slightly when the aileron is >deflected? It looks like it would have to since the >wing aileron torque tube, CS151, that deflects the >aileron is not coaxial with the aileron hinge pins. As you surmise, it does in fact move axially. However, the distance it moves is minuscule, given the distance from the non-coaxially located tube and hinge pin on the aileron to the phenolic (or in my case Delrin (tm) and in other cases ball) bearing. If it's a few thousandths of an inch, it's a lot - it's very difficult to even see any axial motion as it occurs. Since the linkages to the rest of the system have ball joints in them, this small motion (or even a much larger motion) are no problem, as long as there's nothing right next to the linkages for them to hit (which there shouldn't be anyway). What I noticed in my system that was more important than the axial motion was the fact that the hole in the bearing needed to be slightly beveled, since as the tube rotates it also moves it's rotational axis. This meant that it would bind as it reached the ends of it's motion, when it was perfectly free and smooth in the middle. I opened up the inboard and outboard sides of the hole (bevels exaggerated due to wonderful ASCII art :-) ): | | | | \ / \ / -- -- / \ / \ | | | | This gave me much closer to line contact around the perimeter of the tube, and got rid of all the binding. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Tue, 2 Dec 97 7:43:31 EST From: "Nick J Ugolini" Subject: COZY: Re: Torque tube You do not want friction. The navaid autopilot will work much better without any PLAY. When flying you move the stick about 1/16-1/8" for elevator movement (when holding alt) and maybe 1/2" for aileron. My plane are somewhat unstable.,,, ,> It does not automaticly return to stright and level flight when you let go of the stick. When in a bank, and release the stick it will stay in the bank. When straight and level, alt holding is very good in a canard aircraft, BUT the my plane flys straight for a while (about 10 sec) then it starts to bank, one direction or the other. Autopilot is a big help (or a second pilot) when doing anything which requires both hands. Friction wont help, reducing play will. I have maybe .020" play in the right bearing. This translates to 1/8"-1/4" play in the Right aileron. The Left aileron has no play...see the problem? The otherside of the instablilty is that the plane is a joy to fly, It is very responsive, and drive like a sports car vice a mack truck (a C172). ------------- Original Text From: , on 12/1/97 4:59 PM: Thanks Nick. Back in the archives, Marc mentions using Delrin and I think someone actually used a ball bearing. I would think though, for a damped response, you might want some amount of friction in the system without the downside of wear that creates more and more slop over the life of the bearing. Maybe all the other components in series already contribute enough friction for this purpose. Or, maybe you don't need any at all. John Fritz fritzx2@aol.com Date: Wed, 03 Dec 1997 23:25:51 -0500 From: Ian Douglas Organization: WTC Subject: COZY: Torque Tube Bearings After looking at a Velocity Elite 123R FG last night, I was presently surprised when I saw how they put sealed ball bearings on their torque tubes. They use a collard bearing pressed into sheet alu. with two small counter sunk screws holding the bearing in. It is simple, light and functional (I had been toying with p-block ideas but the size/weight was a concern. Has anyone else used ball bearings in their Cozy yet? Vance Atkinson used the phenolic (yeh it is probably spelled wrong 8-) but, called out in the plans) and after 1200 hours in his 3 place Cozy has found that the torque tubes are now flapping around. There is a considerable amount of work involved in doing the replacement, so I figured I would like to be able to get 4000 hours out of a set of bearings. As a side note, this Velocity has been in production (2 people) for 14 months and is very near completion - gave me a major boost in the building zone so I took the day off and completed the FC1s that Jeff sent me. The quality of Jeff's work is very high (I was very pleased with what I received). Since Jeff uses a molded shear web / spar cap and does not have the little hump on the TE of the wing, I had to cut out the shear web, the wing root rib and add a piece along the TE so it would fit the forms. The whole thing took 6 hours and now I have wings sitting in the jigs ready for glassing of shear web. Since this was my first crack at the hot wire saw I was very pleased that my little battery charger was able to provide the perfect amount of current at 12 volts to get perfect cuts. The finished pieces (they are still curing) look like factory made. Tomorrow I will cut out new canard cores now that I know how easy it is... Hopefully I will have my first inspection (shear webs - Canada only) done and out of the way before Christmas (I want to take 4 weeks off around the Christmas holidays to get the wings, winglet and canard finished). -- Ian D.S. Douglas MK0069 Totally PUMPED! From: Marc J. Zeitlin Subject: COZY: Torque Tube Bearings (fwd) Date: Thu, 4 Dec 97 10:32:06 EST Ian Douglas wrote: >..... They use a collard bearing pressed into sheet alu. with two >small counter sunk screws holding the bearing in. It is simple, light >and functional.....Has anyone else used ball bearings in their Cozy yet? This has been discussed a number of times - search the archives and the FAQ for details. There are a number of folks using ball bearings (I've got them in my torque tubes near the stick, but delrin elsewhere). There are also a number of folks selling bearing kits - Infinity Aerospace among them. These can range from ball bearings everywhere to only at the wing root. >Vance Atkinson used the phenolic (yeh it is probably spelled wrong 8-) Actually, you've got "phenolic" spelled correctly, but "collared" wrong above :-). -- Marc J. Zeitlin Email: marcz@an.hp.com From: RGCardinal Date: Thu, 4 Dec 1997 23:27:59 EST Subject: COZY: torque tube bearings Organization: AOL (http://www.aol.com) Weldtech offers torque tube and aileron bearing kits for Long eze, cozy aircraft. Friends who have flown them in thier L.E aircraft swear by them. Rob Kittler SN 589 Date: Sat, 20 Dec 1997 13:54:08 -0500 From: David Domeier Subject: Re: COZY: Wing Root Shield Cliff, re "I would suggest some fiberfrax siliconed into the gap might do the trick. Any other suggestions?" I agree and had already decided to seal the gap with silicone. dd MKIV #155 (taxiing successfully, hope to fly soon) From: "Fred I. Mahan" Subject: Re: COZY: Wing Root Shield Date: Sat, 20 Dec 1997 17:53:01 -0500 You can try the expedient of trimming pieces of PVC foam to the right length, sanding them to a wedge shape, and jamming them into the two gaps to see if it makes a performance difference. Assuming that I would see a performance increase, I tried this expedient 10 years ago -- and never took them out. Fred in Florida ---------- > From: CCady > To: Cozy_Builders@hpwarhw.an.hp.com > Subject: COZY: Wing Root Shield > Date: Saturday, December 20, 1997 2:27 PM > > JD, Cool Idea! > > I recall in a previous Cozy newsletter # 52 pg. 3 a builder suffered head > damage to his wing and spar when his exhaust system failed and super heated > air made it's way out in the gap between spars. It was recommended that the > gap between the wing and CS spar be sealed to prevent high pressure air > escaping. Also this high pressure air leaking out thru the wing - CS spar gap > may be a significant drag source?? The wing root shield may not be enough to > block this problem. > > I would suggest some fiberfrax siliconed into the gap might do the trick. Any > other suggestions? > > Cliff > > >>Chapter 23, Engine Installation, of the Long-EZ plans shows how to make > the mandatory aluminum wing root shield. > We used 2 thin sheets of stainless steel with fibrefax sandwiched > in-between.<<