Date: Sun, 16 Mar 1997 21:08:55 -0500 (EST) From: janef@montcalm.cc.milus (Jane Faussett) Subject: COZY: chapter 10 leading edge (gray tape) Under step 5 it says to sand a 1/32 in.x 1 in. wide depression at the outboard end of the canard and to stick gray tape full span along the leading edge so that the top edge of the gray tape is at the tangent point of the leading edge. Just what is (gray tape)? Is it aluminum foil tape, is it duct tape, and what is it's purpose. Does anyone have a good method to get the 1/16" depression in the foam without making a mess? Thanks Tom and Jane Sorry, it's only Mental Pause. Date: Sun, 16 Mar 1997 21:42:21 -0500 From: Mahan Subject: Re: COZY: chapter 10 leading edge (gray tape) Jane Faussett wrote: > > Under step 5 it says to sand a 1/32 in.x 1 in. wide depression at the > outboard end of the canard and to stick gray tape full span along the > leading edge so that the top edge of the gray tape is at the tangent point > of the leading edge. Just what is (gray tape)? Is it aluminum foil tape, is > it duct tape, and what is it's purpose. Does anyone have a good method to > get the 1/16" depression in the foam without making a mess? Thanks Tom and Jane > Sorry, it's only Mental Pause. It means duct tape, for a glass release. Fred in Florida Date: Sun, 16 Mar 1997 21:47:58 -0500 (EST) From: DFinn7971@aol.com Subject: Re: COZY: chapter 10 leading edge (gray tape) In a message dated 97-03-16 21:12:55 EST, janef@montcalm.cc.milus (Jane Faussett) writes: << Just what is (gray tape)? Is it aluminum foil tape, is it duct tape, and what is it's purpose. Does anyone have a good method to get the 1/16" depression in the foam without making a mess? >> Gray tape is the handiman's friend -- Duct Tape. I used a long sanding block on the canard.Try putting tape down along the edge of the depression. Sand up to the tape. If you go a little far the tape will protect the foam. In other areas where it is necessary to make a depression I use a router. It gives an accurate depth and produces a neat job. I used it to carve the depression for the landing brake. Sometimes it is necessary to mount the router on a large piect of plywood that will bridge the width of the depression. Dick Finn Date: Sun, 16 Mar 1997 20:03:55 -0700 (MST) From: Ron Lee Subject: Re: COZY: chapter 10 leading edge (gray tape) At 21:08 97/3/16 -0500, you wrote: >Under step 5 it says to sand a 1/32 in.x 1 in. wide depression at the >outboard end of the canard and to stick gray tape full span along the >leading edge so that the top edge of the gray tape is at the tangent point >of the leading edge. Just what is (gray tape)? Is it aluminum foil tape, is >it duct tape, and what is it's purpose. Does anyone have a good method to >get the 1/16" depression in the foam without making a mess? Thanks Tom and Jane >Sorry, it's only Mental Pause. > I use duct tape. The point is to have any fiberglass laid over it be removable. I suspect that you will knife trim along the tape edge (tangent line) then remove the tape and overlaying glass. If another layer of glass will overlap the layup you make at this point, say from the top surface, you should also peel ply the first layup. The peel ply would be parallel to the duct tape, maybe even "touching" it, but on top of the glass above the tangent line, whereas the duct tape would be below the glass and below the tangent line (leading edge). Did this make matters worse? Ron Lee Date: Wed, 9 Apr 1997 17:25:26 -0400 (EDT) From: Nigel Field Subject: Re: COZY: Earth to anyone, earth to anyone. -Reply At 02:48 PM 4/9/97 -0400, AlWick@aol.com wrote: > > >Ok, Ok, I confess. I've made a few errors during construction....... >Almost got trapped in canard template mod (increased incidence). Didn't >realize the importance of the flat sides of template (non-cutting surfaces). >Don't recall any other errors, but I think I made a couple others. Shows just >how excellent the plans are. > Hi Al, Yea that one can bite you but bet I got you all beat. When I made my canard I briefly refered to the plans for the pertinant dimensions, since after all this was my 3rd canard wing so I knew all about it, right ?? :-) ,, so I measured and cut the cores and did all the rest right up to installing the hinge tabs when I suddenly realized I had reversed the dimensions of 3 large foam blocks, you know the first measurement you make. So I had a long centre piece and 2 short end pieces, plus tips, all done and glassed and no way to recover any of it. Its too big for a book end, too stiff for a diving board, hell I don't even have a pool, too far from the ogwash to be a surf board, but I guess it might make a good structural test piece some day. Stupid Nigel MK III on the way Date: Mon, 2 Jun 1997 07:41:29 -0500 (CDT) From: wkasty@ix.netcom.com Subject: COZY: Chapter 10 canard glassing Hi All, I'm ready to glass the bottom of the canard. Page 6, figure 39 tells you to "pull fabric until this edge covers 1/2 of outboard core." My pieces of BID don't reach this far, I assume he doesn't really want you to pull the fabric out of alignment? What did anyone else experience with this layup? Bill Kastenholz Cozy MKIV #536 wkasty@ix.netcom.com Date: Mon, 02 Jun 1997 19:39:59 -0700 From: Michael Antares Subject: Re: COZY: Chapter 10 canard glassing At 07:41 AM 6/2/97 -0500, you wrote: >Hi All, > > I'm ready to glass the bottom of the canard. Page 6, figure 39 >tells you to "pull fabric until this edge covers 1/2 of outboard core." >My pieces of BID don't reach this far, I assume he doesn't really want >you to pull the fabric out of alignment? What did anyone else experience >with this layup? > Strange as it seems, I think that is exactly what he wants you to do. You will notice that the width of the BID pieces you have previously cut out are considerably wider than the canard. The reason for that is to allow for some stretching to obtain the proper length. Obviously the stretching should be done to keep the individual threads straight--they are just going to change their angle slightly when you do the stretching. Others can comment on this, but that is how I remember doing the canard... 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. Date: Tue, 17 Jun 1997 23:25:01 -0400 From: Jim Hocut Subject: COZY: The Sad and Premature Demise of My Canard It was with much sadness today that I decided my canard was too sick to save and faced the reality that the only humane thing to do was have it put to sleep. All the filling and sanding and filling and sanding in the world wasn't going to ever get it to come close to matching the templates and have a happy (and safe !!!!) life. In the interest of science, and the hope that the demise of my beloved canard was not in vain, I would like to offer a section of it to anyone who can perform a proper autopsy. I would like to put to rest some of the questions that have been raised about hard shelling and 2427 (yes, I did, and yes I will again). I cut off several pieces from both the leading and trailing edge, and will get a piece in the mail to anyone who would be interested in performing any kind of testing you feel appropriate and reporting the results here. (No mere souvinir hunters please.) By the way, I feel much safer about the possibility of a bird strike. A wimpy little bird couldn't come close to having the damage potential of a 5 pound hammer being swung by a p'd off builder taking out his frustrations. It is with great satisfaction that I report the damage inflicted by the p'd off builder swinging a 5 pound hammer at the leading edge was insubstantial, nowhere near enough to cause a premature landing. (BTW, the longer I thought about my family riding with me attached to a canard I didn't have full confidence in the easier the decision became. Lesson learned - next time the cores will be PERFECT before one strand of glass cloth touches them.) Jim Hocut jhocut@mindspring.com Date: Tue, 17 Jun 1997 22:38:03 -0600 (MDT) From: Ron Lee Subject: Re: COZY: The Sad and Premature Demise of My Canard At 23:25 97/6/17 -0400, you wrote: >It was with much sadness today that I decided my canard was too sick >to save and faced the reality that the only humane thing to do was >have it put to sleep. All the filling and sanding and filling and >sanding in the world wasn't going to ever get it to come close to >matching the templates and have a happy (and safe !!!!) life. > snip >Jim Hocut >jhocut@mindspring.com GOOD decision Jim. My long-EZ canard was also rejected due to problems in the hotwiring that caused a legthwise depression in both upper and lower surfaces. I filled it with extra UNI many years ago but decided that it MIGHT have undesirable loading effects at some point. So I am going to redo it. It will cost a few hundred dollars but so what. I will feel better about it. Ron Lee Date: Wed, 18 Jun 1997 09:47:50 -0400 (EDT) From: CozyBldr@aol.com Subject: Re: COZY: The Sad and Premature Demise of My Canard Before you cut it up, you may want ot consider loading it to breaking point. I would love to know what it could handle. Paul Stowitts Cozy Mark IV #200 Date: Sat, 21 Jun 1997 18:33:55 -0400 (EDT) From: Gunrider@aol.com Subject: COZY: Short Canard I had my canard professionally built by a listed builder and it is 3/10 to4/10 short on the trailing edge all the way across according to both templates. What's up with this? It does not reach F-22 as shown in the plans. Am I in trouble? Can a trailing edge be safely added? Help! Hugh Farrior From: Marc J. Zeitlin Subject: COZY: Short Canard (fwd) Date: Mon, 30 Jun 97 15:16:03 EDT Hugh Farrior writes: >I had my canard professionally built by a listed builder and it is 3/10 >to4/10 short on the trailing edge all the way across according to both >templates. What's up with this? Sounds like professional builder error, to me. Does this include the elevators, or just the canard? >It does not reach F-22 as shown in the plans. Am I in trouble? Maybe, maybe not. Don't know why you haven't heard from more knowledgeable people yet, but I'll throw in my $0.02, since I've had canard issues. See: http://www.ultranet.com/~marcz/cozy_mkIV/chapters/chap11_2.html John Roncz was very noncommittal in his response to my questioning - I kind of expected him to say "Don't fly that thing - it's got to be perfect!!!" but he didn't. How does the shape of the airfoil match up with the templates? Is the shape right, but the T.E. of the canard is just 0.3" or 0.4" short? If so, and the elevators have NOT been mounted yet, you could easily extend the T.E. with some BID layers, and then mount the hinges so that the elevators are in the right place. If the elevators are already mounted, and the shape isn't quite right (something like my canard, but in a different axis) then you can either follow John R.'s advice and just fly it and see what happens (my guess is that the issue is a small one - the difference in canard area is small (less than a few %) and would lead to a minor difference in cruise elevator position that might even be offset by the implicit increase in camber created by the shorter chord. Of course, the most reasonable solution might be to approach the builder, inform them of the problem and lack of conformance to the plans, and get them to build you another canard that was correct. Hell, you paid for it, it should meet the plans. Once again, we find that not having tolerances in any of these dang homebuilt plans leads to needless worrying AND to lack of precision at the same time. >Can a trailing edge be safely added? See above. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Thu, 28 Aug 1997 09:37:31 -0500 From: tpierce@ghg.net (Terence J. Pierce) Subject: COZY: Dihedral Canard Jeff Russell and whoever else knows, Can you give us some details on what needs to be done to make a dihedral canard. Like how do you make the transistion from the flat section of the canard that goes through the fuselage to upward angle of flying surface. And how do you do the elevators? Are you using some kind of universal joint? I think I want to use a diheral canard, I just need know how it is done and how hard it will be to do this. Thanks, -- Terry Pierce mailto:tpierce@ghg.net Cozy Mark IV #600 From: N11TE@aol.com Date: Thu, 28 Aug 1997 11:53:38 -0400 (EDT) Subject: Re: COZY: Dihedral Canard Two suggestions on the bent canard: Jeff Russell is now selling a molded bent canard. It comes out of the mold finished on the top with the correct shape. Mine is already finished (unfortunately straight) but if I was to start over this is the way I would go. Contact him for the details. Vance Atkinson sells a complete set of plans to build the bent canard yourself. Contact him for a price. He did it first and I'm sure his plans would be worth it. As another said, the bent canard sure looks snarky. I flew to Oshkosh in Jeff's plane and can report that a bent canard definitely flys great. Good luck. Tom Ellis N11TE@aol.com Cozy MKIV plans #25 now AeroCanard 540 From: "Fred I. Mahan" Subject: Re: COZY: Firewall-Engine Mnt. Hardpoints. Date: Mon, 22 Sep 1997 11:02:54 -0400 This technique also works for removing mis-located or damaged canard hangars from canards. Fred in Florida ---------- > From: Bulent > To: Rego Burger > Cc: Cozy Builders > Subject: Re: COZY: Firewall-Engine Mnt. Hardpoints. > Date: Monday, September 22, 1997 11:52 AM > > HI Rego, > About your bolts glued in the epoxy: I had removed parts like that > epoxied solid by not so bright friend of mine, by heating fast the metal > with a propane torch while pulling on the part. Only the epoxy touching > the metal melts and releases the metal without heating the rest of the > aerea. Good luck. > Bulent > CZ MK-IV #66 From: lschuler@cellular.uscc.com Date: Mon, 29 Sep 97 12:28:48 -0600 Subject: COZY: In search of the perfect core --simple boundary Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Calvin Hobbs wrote: >If you could give three tips to cut perfect canard and wing cores >What would they be? Since I'm just about to strt on my canard, here is what I have been thinking about: 1. Make templates out of something that won't melt and can provide a VERY SMOOTH edge such as aluminum. 2. Make templates about 1/16" oversized, leaving the final trim lines on the templates. 3. After hot-wire cut, carefully remove the 1/16" from the templates and use these "final" templates for spline sanding (80 to 100 grit; slow, but will keep the templates from wearing too much) the foam to perfect shape. May be too much trouble, but this is what I "might" do. Larry Schuler #500 starting ch-10 lschuler@cellular.uscc.com --simple boundary Content-Type: text/plain; charset=US-ASCII; name="RFC822.TXT" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="RFC822.TXT" Received: from gatekeep.uscc.com by cellular.uscc.com (ccMail Link to SMTP R8.00.01) ; Fri, 26 Sep 97 21:23:10 -0600 Return-Path: Received: from www.uscc.com (www.uscc.com [204.179.101.2]) by gatekeep.uscc.com with ESMTP id WAA09027 for ; Fri, 26 Sep 1997 22:19:25 -0400 (EDT) Received: from palrel1.hp.com (palrel1.hp.com [156.153.255.235]) by www.uscc.com with ESMTP id VAA06789 for ; Fri, 26 Sep 1997 21:20:09 -0500 (CDT) Received: from hpwarhw.an.hp.com (hpwarhw.an.hp.com [15.57.193.122]) by palrel1.hp.com (8.8.6/8.8.5tis) with SMTP id TAA22305 for ; Fri, 26 Sep 1997 19:22:10 -0700 (PDT) Received: by hpwarhw.an.hp.com (1.37.109.8/15.5+IOS 3.22) id AA29950; Fri, 26 Sep 1997 22:21:27 -0400 Received: from hp.com by hpwarhw.an.hp.com with SMTP (1.37.109.8/15.5+IOS 3.22) id AA29745; Fri, 26 Sep 1997 22:21:21 -0400 Received: from osceola.gate.net (osceola.gate.net [199.227.0.146]) by hp.com (8.8.5/8.8.5tis) with ESMTP id TAA02895 for ; Fri, 26 Sep 1997 19:19:27 -0700 (PDT) Received: from spool2.gate.net (root@spool2.gate.net [198.206.134.30]) by osceola.gate.net (8.8.6/8.6.12) with ESMTP id WAA47702 for ; Fri, 26 Sep 1997 22:17:04 -0400 Received: from 120mz (tpafl2-5.gate.net [199.227.4.132]) by spool2.gate.net (8.8.5/8.7.3) with SMTP id WAA24398 for ; Fri, 26 Sep 1997 22:17:05 -0400 (EDT) Message-Id: <342C6C54.7CC2@gate.net> Date: Fri, 26 Sep 1997 22:15:48 -0400 From: "Calvin N. Hobbs" Organization: First Church of Yoda, Master of Jedi Knighthood, Inc. X-Mailer: Mozilla 3.0 (Win95; I) Mime-Version: 1.0 To: cozy_builders@hpwarhw.an.hp.com Subject: COZY: In search of the perfect core Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-cozy_builders@hpwarhw.an.hp.com Precedence: bulk Reply-To: "Calvin N. Hobbs" --simple boundary-- Date: Wed, 01 Oct 1997 16:21:00 +0200 From: Rego Burger Subject: COZY: In search of the perfect core -Reply Attention Larry! The Templates for the wings and canard are sized to cater for the hot wire changes....it's in the plans..:-) Even though rated critical I can't see a major problem unless the guys are setting their hot wires(cutters ) to a too high temp. The secret to foam cutting is too find the lowest temp that will move the wire and leave the angel hair when moving out after the cut. Oh! either your mail got delayed badly or your P.C's clock is a day or two out...:-) no big deal I just get your mail on top of the page instead of the bottom. It shows 29 Sept.???? Your reply to e-mail address is not working? :-) Rego Date: Fri, 10 Oct 1997 10:26:21 -0400 From: bil kleb Organization: NASA Langley Research Center Subject: COZY: chap 10 - canard lift tabs [summary: ordering the wrong parts from brock?] the plans call for ordering NC-CLT from brock. just in case you haven't experienced brock, cozy mark iv parts aren't the easiest to find in brock's catalog, they are scattered about in various sections. i finally found the part in the "new canard" section. this is what i ordered. when i went use to the tabs, i found that the three 1/4" holes along the top of each were not 1/4", but less: 13/64". i had to drill them out and debur. later, upon reading chap 12, i noticed that the plans say, "and using the #10 pilot holes in the lift tab[.]" my NC-CLTs have no such pilot hole pre-drilled, i.e., they do not look like NC-CLT as drawn in fig. 14, chap 10. looking more closely at the brock catalog, the NC-CLT picture in the "new canard" section seems to confirms both of these traits (no #10 pilot hole and smaller top holes--comparing the nutplate holes and the tabs). however, in the "cozy" section, there is a part listed as NC-CLI. it looks like the correct part. was there a plans correction i missed? (NC-CLT -> NC-CLI) -- bil From: Marc J. Zeitlin Subject: COZY: chap 10 - canard lift tabs (fwd) Date: Fri, 10 Oct 97 11:08:18 EDT bil kleb writes; >when i went use to the tabs, i found that the three 1/4" holes >along the top of each were not 1/4", but less: 13/64"...... >later, upon reading chap 12, i noticed that the plans say, >"and using the #10 pilot holes in the lift tab[.]" my NC-CLTs >have no such pilot hole pre-drilled........ Wow. That's unbelievable. Brock's "Quality Control" system missed something? They didn't make the part exactly to the plans? I'm shocked - shocked, I say! :-) :-) added for the sarcasm impaired. Mine were exactly the same. drill out the existing holes, put in the ones that are supposed to be there. This, for a what, $7 piece of 1/8" aluminum sheet metal? Unbelievable. Another argument against monopolies - where's the Taft-Hartley Act when you need it? >.... however, in the "cozy" section, >there is a part listed as NC-CLI. it looks like the correct part. >was there a plans correction i missed? (NC-CLT -> NC-CLI) Interesting. This wouldn't be the first part that was listed in two seperate places in the Brock catalog. When I ordered my parts two years ago, I don't remember seeing any "NC-CLI"'s in the brock catalog (although I wasn't looking for them, I was looking for the "NC-CLT"'s, since they're the only things the plans say anything about, both in Chapter 2 and in Chapter 10). If Brock is changing part #'s on us without checking with Nat (which I doubt - I assume this is just a typo with a picture of what they're REALLY supposed to be shipping to us but don't), we're really in trouble. No, there's been no plans correction that you missed, at least with regard to this issue. -- Marc J. Zeitlin Email: marcz@an.hp.com From: Howard Calk Subject: RE: COZY: chap 10 - canard lift tabs Date: Fri, 10 Oct 1997 11:25:13 -0400 The new canard plans from RAF clears this up. The lift tabs (NC-CLT) in the new canard section of Brock's catalog are for retrofitting the new Roncz canard to an existing plane. These lift tabs are slightly larger; do not have the #10 holes drilled; and for some unknown reason have the nutplate holes drilled smaller. The correct lift tabs to order for new construction were the ones specified CLT for original GU canard on the Long EZ section (I don't know if the Cozy section also has these listed). You can still use the ones you ordered. Just ream out the existing holes to .25" (as you have done) and drill the #10 pilot holes. Location for the #10 holes is not all that critical as each canard installation is custom. Just try to center them in the outside radius. You can match drill them if you like. I know all of this because I ordered the same ones myself but I am using the new canard plans. After discovering the same discrepancies went back to check the plans in more detail. Howard Calk Long EZ builder From: Jim Hocut Subject: RE: COZY: chap 10 - canard lift tabs Date: Fri, 10 Oct 1997 08:55:00 -0700 I don't see why more builders don't make their own. I'm on my 2nd canard, and Brock is not getting any of my money this time around. These things are so simple it's ridiculous, rough cut on a band saw, a little fine tuning on a table top belt sander, and then over to the drill press. Will probably make mine a little over-sized for no good reason. Date: Tue, 14 Oct 1997 12:44:51 -0400 From: bil kleb Organization: NASA Langley Research Center Subject: Re: COZY: chap 10 - canard lift tabs Jean-Jacques CLAUS wrote: > > Screws of fixing to the canard are always the AN4. On the > other hand screws of fixing to the F22 have been replaced by the > AN6. so are the CNL canard attach bushings just reamed to fit the new AN6 bolts, or are the attach bushings also made larger in diameter? -- bil From: lschuler@cellular.uscc.com Date: Thu, 04 Dec 97 15:25:08 -0600 Subject: COZY: Canard Bottom help First, a thank you goes to Phillip Johnson who suggested (over a California home-brew at Oshkosh) that it may be better to very slightly overbuild the spar caps and use a belt sander to shape it up (down) to the template. I started with a block sander, but gave in after taking 6 hours to get 25% of it done and bought a decent 3" belt sander; worked great; did the rest in one evening. Just needed to be "VERY" careful, but zero bumps or UNI layer transitions as a result; only a couple of repairable (micro) nicks in the foam (I used some thin duct tape to protect the foam). Only took some minor touch-up by hand. Thanks Phillip. Now that I have a belt sander, I'll do same on the wings and won't be so concernd about the end-cuts (taper) when laying in the spar tapes. The layup should go much faster. Now for a question about the tail. Cozy Plan calls for a 1" strip of peel ply along the underside of the canard tail. This is for the eventual glass-to-glass when the top is done. Looking at Plan photos, it appears that a good chunk of foam is removed with this tape later after the top tail is cut off but the plans don't say how much of the tape is actually laid on the foam (1/4", 1/2", all 1" etc.). I held the top template on the ends of the canard and traced the eventual curvature resulting after the top tail foam is removed. It appears that this curve will meet the bottom of the tail right at the trailing edge providing little, if any, glass-to-glass contact. It appears that the more foam that is peel plied, the greater the gap will be between the top glass and the bottom glass caused by the required bottom curvature in the area. This would result in cumbersom shaping and flox-filling later; however, the plans and photos indicate that the top is shaped per the template and ends with what appears to be about 3/4" (best guess since Nat didn't specify) glass-glass contact at the tail. I quadruple-checked my templates and everthing appears to match perfectly as they should. I used the "A" hot wire drawing (traced via carbon paper for both A & B templates simultaneously) since the "A" and "B" drwaings don't match and "B" doesn't match any of the other templates very well either. The "A" drawing was the closest match to the other template drawings, as provided, and I made the necessary micro-corrections to match (less than a pencile line) the other drawings to "A" when making all the templates. I did make the recommended change to the trailing edge (needed for full-up elevator) and adjusted templates accordingly. All this checks ok. What am I doing or did I already do something wrong? Everything else seems darn near perfect. Must be somthing simple 'cause I can't see it. Larry Schuler Cozy plans #500 Wondering in Wisconsin and about ready to scrap a canard and templates. lschuler@cellular.uscc.com From: Marc J. Zeitlin Subject: COZY: Canard Bottom help (fwd) Date: Thu, 4 Dec 97 17:22:37 EST Larry Schuler writes: > ....... Looking at Plan > photos, it appears that a good chunk of foam is removed with this > tape later after the top tail is cut off but the plans don't say how > much of the tape is actually laid on the foam (1/4", 1/2", all 1" > etc.). I remember in the dim dark past that somewhere it says that all glass/glass bonds should be at least 1/2" wide. I usually shoot for 1/2" to 3/4". > It appears that the more foam that is peel plied, the greater the gap > will be between the top glass and the bottom glass caused by the > required bottom curvature in the area. This would result in cumbersom > shaping and flox-filling later; however, the plans and photos indicate > that the top is shaped per the template and ends with what appears to > be about 3/4" (best guess since Nat didn't specify) glass-glass > contact at the tail. I don't know that you're going to want to pay any attention to what I say regarding canards given my experiences oaf-wise :-), but here's what I'd do: peel ply about 3/4" wide (so that after trimming the canard trailing edge, you'd have about 3/4" of glass/glass bond). However much foam comes off, comes off - it won't be more than 1/16" or so, right? Make a smooth transition from the foam to the exposed peel plied glass (should be no more than 1/16" high or so) and then lay up the top skin. At that point, you'll have to micro fill the trailing edge a bit, but certainly not a lot. The micro should taper from 1/16" thick max down to nothing right at the T.E. The top surface is barely radiused at that point, so shaping the micro will be easy - no floxing at all. > What am I doing or did I already do something wrong? Everything > else seems darn near perfect. Given all the variation that other people (including myself) have seen with canard construction, I wouldn't presuppose that you've done anything wrong. The tolerances are tight (and not given) and the angles are small, so that a tiny variation can lead to a large thickness difference. My $0.02. -- Marc J. Zeitlin Email: marcz@an.hp.com From: lschuler@cellular.uscc.com Date: Thu, 04 Dec 97 17:24:21 -0600 Subject: COZY: Canard Bottom help (fwd) --simple boundary Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Marc wrote: >snip >I don't know that you're going to want to pay any attention to what I >say regarding canards given my experiences oaf-wise :-), but here's what I read the archives etc first.... you did have a bit of a time didn't you.. :-) >I'd do: peel ply about 3/4" wide (so that after trimming the canard >trailing edge, you'd have about 3/4" of glass/glass bond). However much >foam comes off, comes off - it won't be more than 1/16" or so, right? >Make a smooth transition from the foam to the exposed peel plied glass >(should be no more than 1/16" high or so) and then lay up the top skin. >At that point, you'll have to micro fill the trailing edge a bit, but >certainly not a lot. The micro should taper from 1/16" thick max down >to nothing right at the T.E. The top surface is barely radiused at that >point, so shaping the micro will be easy - no floxing at all. >snip Hmmmmm... I'll look at this tonight. Have a stupid mental picture of 1/4" for some reason (probably due to a bit of frustration). Shouldn't be that bad over a 3/4" span. Seem to remember Floxing transitions where it ends up glass-glass like the seats. Seems like it would be more sturdy, but sertainly agree that micro is always more robust than any of the foams we use anyway.... Thanks. Larry Date: Thu, 04 Dec 1997 18:27:47 -0500 From: "Jeff S. Russell http://www.AeroCad.com" Organization: AeroCad Inc. Subject: Re: COZY: Canard Bottom help lschuler@cellular.uscc.com wrote: > the plans and photos indicate that the top is shaped per the > template and ends with what appears to be about 3/4" (best > guess since Nat didn't specify) glass-glass contact at the tail. You must have min. .375 (3/8") of glass to glass trailing edge for a good enought bond between skins. Anything more then 1/2" will mean more micro fill in that area. Peel ply under the btm skin should be placed about the 1/2" on the foam and the rest of the peel ply should hang over the foam. Canards are the hardest airfoils to build because of more smaller pieces of foam and more of them for the part. I would rather build 3 sets of wings to 1 canard. hope that helps -- 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: Thu, 04 Dec 1997 16:25:59 -0800 From: "LCDR James D. Newman" Organization: INFINITY Aerospace http://www.flash.net/~infaero Subject: COZY: Re: Suggestions FYI/FWW Hi Larry, Marc and All, >1. Nat suggests brads or staples to hold the peel ply in place on the bottom of the canard's tail when doing the skin lay up. I plan to use some double-sided plastic tape.< The brass brad trick is from the Long-EZ plans and is in Rutan's 90 minute Moldless Construction Builders video. I use a 3-M spray adhesive sprayed on one side of the peel ply strips - no bumps from the brads and works much better. Can be obtained at places like Home Depot. Also lay out the aileron outline with the 3-M spray on peel ply trick. Lay the center line of the 1" wide peel ply down the cut line of the aileron from the trailing edge up to the lenghtwise cut so you cut down the middle of the peel ply when you cut the ailerons out. Then you'll have 1/2" of peel ply on both the wing and aileron close out. Do the rudders too. >I remember in the dim dark past that somewhere it says that all glass/glass bonds should be at least 1/2" wide. I usually shoot for 1/2" to 3/4".< Correct. Always have at least 3/8" to 1/2" glass to glass close out. I think this point is in the front of the plans in the education section. HTH. Infinity's Forever, JD Date: Fri, 05 Dec 1997 10:20:24 -0800 From: Stet Elliott Subject: COZY: Re: [canard-aviators] Canard Bottom help lschuler@cellular.uscc.com wrote: > > Now for a question about the tail. Cozy Plan calls for a 1" strip of > peel ply along the underside of the canard tail. This is for the > eventual glass-to-glass when the top is done. Looking at Plan photos, > > it appears that a good chunk of foam is removed with this tape later > after the top tail is cut off but the plans don't say how much of the > tape is actually laid on the foam (1/4", =BD", all 1" etc.). Below is an article from the Canard Pusher Newsletter that answers your question about the trailing edge overlap on the canard. Sorry the columns don't line up, but, well, you get what you pay for! -- Stet Elliott flyez@earthlink.net Long-EZ N321EF **From CP32-6 ** CAUTION - TRAILING EDGE CLOSE OUTS It is very important for structural integrity, that you ensure that your trailing edges of the canard, elevators, wings, ailerons, winglets and rudders meet the prescribed minimums in the plans. Do not accept delaminations in the trailing edge glass to glass area. Even the smallest delam can get moisture in it which will freeze and expand when you climb through the freezing level, and thus delaminate further and further with each occurrence until it could weaken the overall integrity. About the quality of your trailing edge glass to glass close outs - accept nothing less that perfection in this area. Always sand smooth every lap after cure - do not leave them joggled as shown. **SKETCHES OMITTED** LAP DIMENSION Ignoring the proper procedure here could result in serious consequences, even structural failures! Here is a list of these areas. The minimum dimension should be considered an absolute minimum. If you don't meet this criterion it requires repair before you fly. Glass Lap Minimum Dimension Shown Acceptable Lap Canard 0.45" 0.3" Elevators 0.25" 0.2" Wings 0.6" 0.5" Aileron cut outs 1.0" (top) 0.75" (top) 0.75" (bottom) 0.52" (bottom) Ailerons 0.5" 0.3" Wing Root Rib 0.6" 0.4" Winglets 0.6" 0.4" **SKETCHES OMITTED** From: lschuler@cellular.uscc.com Date: Fri, 05 Dec 97 15:02:57 -0600 Subject: Re: COZY: Re: [canard-aviators] Canard Bottom help Good CP info Stet. Unfortunately, acheiving a perfect glass-glass contact for the distance specified in the quoted CP is impossible, given the template drawings at hand without deviating from them. That would be kind of like second-guessing God (John Roncz). Assuming of course that the copies of his work I paid good money for (via Cozy plans) were perfect to start with.... WHICH THEY ARE NOT. [Some day maybe Nat will fix this rediculous paper copy problem by putting the drawings in CAD files; unfortunately, I think he still trusts pencils and erasers more than the mouse and undo icon. :-)] Also, thanks to everyone who replied with suggestions on my predicament. After mesuring last night, I came up with a potential 1/4" gap if I were to use 3/4" of the peel ply, and about 1/8" if I use 1/2" of peel ply. Either way it appears to taper to zero gap at about 0.1" from the trailing edge (not ideal). It would certainly be worse If I had not followed Nat's change for raising the trailing edge slightly (for elevator clearance). Unless someone can come up with something better, here's what I decided: First, I'll keep working on it; if nothing else, I will certainly have a better understanding on how to do another one different. Think I will go for 1/2" of peel ply. The 1/8" gap should be relatively easy to fill and taper per top template. The trick will be to keep the remainig foam edge nice as I rip the peel ply off and sand the glass. I also decided to use wet flox rather than micro for the small fill; I believe it will stand up better and provide a more solid trailing edge; overal best integrity. Easily MUCH better than leaving the foam in the taper. Using flox seems to be the best alternative to reshaping the canard template drawings to the way they should have been provided (assuming of course that I could change my name to John Roncz :-)). The weak link in this area is the peel strength of the epoxy; and, flox is darn near as good as pure epoxy; and, better than micro. It was suggested I could leave the gap, ensure glass-glass over the 1/2" or so span and fill the resulting joggle on the top with micro later. Unfortunately, an 1/8" joggle would make the joint (and whole top skin and tail) weaker than if it were a smooth taper filled with flox. Larry Schuler lschuler@cellular.uscc.com From: Marc J. Zeitlin Subject: Re: COZY: Canard Bottom Help (fwd) Date: Fri, 5 Dec 97 17:45:51 EST Larry Schuler writes: > I also decided to use wet flox rather than micro for the small fill; I > believe it will stand up better and provide a more solid trailing > edge; overal best integrity. Easily MUCH better than leaving the foam > in the taper. If I understand you correctly, you're planning on using peel ply and filling any gap under the skin with flox all the way back to the T.E., then glassing the top skin over the flox? Or are you going to fill the top surface with flox only back to within 1/2" of the T.E., ensuring that you have a 1/2" glass/glass bond at the T.E.? If #1, I'm concerned...... > ......The weak link in this area is the peel strength of the > epoxy; and, flox is darn near as good as pure epoxy; and, better than > micro. Yes, but see below....... > It was suggested I could leave the gap, ensure glass-glass over the > 1/2" or so span and fill the resulting joggle on the top with micro > later. Yeah, by me, I think. > .... Unfortunately, an 1/8" joggle would make the joint (and whole > top skin and tail) weaker than if it were a smooth taper filled with > flox. At first I thought you were correct here, but the more I think about it, the more I think this is not right (if I interpret what you're going to do correctly - see my first paragraph #1). Here's why I disagree: The glass/glass bond at the T.E. does a few jobs. First, it ensures that everything stays in the right place and that moisture, etc. don't get inside the wing (per Stet's caution from the CP). Second, it assists in the bending strength of the wing by virtue of doing it's first job. Thirdly, and what causes me to hesitate to endorse your solution #1 is that the g/g bond also is critical in ensuring the _TORSIONAL_ (twisting) strength and stiffness of the canard. If the T.E. was open, you'd have what's called a "C" section (since there's an opening on one side) and the torsional stiffness could go WAY down. Now, the flox is not an opening, but neither is it a g/g bond, and the thicker it gets the less it resembles a g/g bond. The g/g bond provides for a "D" section, since the skin is closed all the way around, and it becomes much stiffer in torsion. The flox's (and epoxy's) stiffness is orders of magnitude less than that of the glass - in a g/g bond, the epoxy may be only a couple of thousandths of an inch thick. You're looking at 1/8", or upwards of 10 times that amount, if not more. So, without a full torsional analysis, I'd be hesitant to put any flox between the two layers of glass. You very probably would be OK, but you'd never know for sure without the analysis, and this is a critical strength area. I'd still recommend the joggle (even a 1/8" joggle) in the top surface, with a micro (or micro/flox mixture) fill (and possibly a light glass cloth cover if you're worried about thick micro cracking). The strength would be acceptable with the joggle, and you'd only be adding a minimal amount of extra finishing work. There's a reason they call for a glass/glass bond at the T.E. of the wings/canard, rather than the flox corners that are called out on some bulkheads and other areas that aren't subject to the kind of stresses that the wings/canard will see. If you're doing solution #2 in the first paragraph and will have a 1/2" glass/glass bond with flox inside PAST the 1/2", then - _nevermind_ ........ :-). -- Marc J. Zeitlin Email: marcz@an.hp.com From: lschuler@cellular.uscc.com Date: Fri, 05 Dec 97 18:12:21 -0600 Subject: Re[2]: COZY: Canard Bottom Help (fwd) Marc, Lets see if I can do ASCII art: What would happen (in general) to the tortional stifness of the "D" if a joggle were placed at the top of the "D" about a half inch to the right of the trailing edge? See my ASCII drawing below.... Holding the bottom skin stationary and sliding the top skin from left to right makes that little jog look like a double-hinge to me. Granted, glass-glass is best; but, given the drawings I have (following them again will result in the same situation) wouldn't shaping the top glass in a smooth curve, with at least a 0.1" glass-glass contact at the left, and max 1/8" thickness of flox between the top and bottom skins at the 1/2" point (the rest is styrofoam) be better than a glass hinge in the top skin? JOG ________ Canard Top |_......------ ____| TE ---_ - _ Nose--> -_ -_ _ _ -___________Canard Bottom ASCII sucks. Assuming that the 'D' is filled with foam, I am talking about filling that little jog with flox in a taperd manner and laying the top skin over the flox (single operation while the flox is wet). The curve in the bottom skin will not change and is needed for the Fowler elevator. I will also be able to maintain the required curvature of the top. Larry Standing still..... Marc wrote: If I understand you correctly, you're planning on using peel ply and filling any gap under the skin with flox all the way back to the T.E., then glassing the top skin over the flox? Or are you going to fill the top surface with flox only back to within 1/2" of the T.E., ensuring that you have a 1/2" glass/glass bond at the T.E.? If #1, I'm concerned...... At first I thought you were correct here, but the more I think about it, the more I think this is not right (if I interpret what you're going to do correctly - see my first paragraph #1). Here's why I disagree: The glass/glass bond at the T.E. does a few jobs. First, it ensures that everything stays in the right place and that moisture, etc. don't get inside the wing (per Stet's caution from the CP). Second, it assists in the bending strength of the wing by virtue of doing it's first job. Thirdly, and what causes me to hesitate to endorse your solution #1 is that the g/g bond also is critical in ensuring the _TORSIONAL_ (twisting) strength and stiffness of the canard. If the T.E. was open, you'd have what's called a "C" section (since there's an opening on one side) and the torsional stiffness could go WAY down. Now, the flox is not an opening, but neither is it a g/g bond, and the thicker it gets the less it resembles a g/g bond. The g/g bond provides for a "D" section, since the skin is closed all the way around, and it becomes much stiffer in torsion. The flox's (and epoxy's) stiffness is orders of magnitude less than that of the glass - in a g/g bond, the epoxy may be only a couple of thousandths of an inch thick. You're looking at 1/8", or upwards of 10 times that amount, if not more. So, without a full torsional analysis, I'd be hesitant to put any flox between the two layers of glass. You very probably would be OK, but you'd never know for sure without the analysis, and this is a critical strength area. I'd still recommend the joggle (even a 1/8" joggle) in the top surface, with a micro (or micro/flox mixture) fill (and possibly a light glass cloth cover if you're worried about thick micro cracking). The strength would be acceptable with the joggle, and you'd only be adding a minimal amount of extra finishing work. There's a reason they call for a glass/glass bond at the T.E. of the wings/canard, rather than the flox corners that are called out on some bulkheads and other areas that aren't subject to the kind of stresses that the wings/canard will see. If you're doing solution #2 in the first paragraph and will have a 1/2" glass/glass bond with flox inside PAST the 1/2", then - _nevermind_ ........ :-). -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Fri, 05 Dec 1997 22:05:23 -0500 From: "Jeff S. Russell http://www.AeroCad.com" Organization: AeroCad Inc. Subject: Re: [3]: COZY: Canard Bottom Help lschuler@cellular.uscc.com wrote: > Granted, glass-glass is best; but, given the drawings I have > (following them again will result in the same situation) wouldn't > shaping the top glass in a smooth curve, with at least a 0.1" > glass-glass contact at the left, and max 1/8" thickness of flox > between the top and bottom skins at the 1/2" point (the rest is > styrofoam) be better than a glass hinge in the top skin? > > JOG _____ Canard Top > |_...... > ____| > TE --- _ > |1/8| - _ Nose--> > -_ > -_ > _ > _ > -___________Canard Bottom > Larry, I added in where I think you are saying that you will only have 1/8" glass to glass bond. After that, are you saying that you want to stack and taper flox over the foam (not) on fiberglass to smooth out the jog in the canard top skin. If I read you corectly, this is not strong enought glass bond as Marc said for the twisting moment the canard will see. The small amount of fill in this place is nothing in retro to filling the rest of the airplane. You will find this out in the long run. Build smart, stick to your plans :-) -- 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 From: Marc J. Zeitlin Subject: Re[2]: COZY: Canard Bottom Help (fwd) (fwd) Date: Mon, 8 Dec 97 9:59:20 EST Larry Schuler wrote: > What would happen (in general) to the tortional stifness of the "D" if > a joggle were placed at the top of the "D" about a half inch to the > right of the trailing edge? Essentially nothing, unless you've _really_ got sharp corners in the glass. Take a coke can; grab both ends, and try to twist it. Get a feel for how much force it takes to get it to start to crinkle. Now, put a small crease in the can running lengthwise - maybe 1/8" deep or so. Try to twist the can again. If you've only made a longitudinal crease (not too deep) you shouldn't have affected the stiffness of the can much at all. Now, take a tin snips and cut a slice down the length of the can. Now twist it. Uh-oh. This is an (admittedly poor) analogy to what's going on with the wing skin. > See my ASCII drawing below.... Holding the bottom skin stationary and > sliding the top skin from left to right makes that little jog look > like a double-hinge to me. Yes, but it won't be vertical because you'll taper the joggle, right? And it's small (1/8" max) and the torsional stiffness is resisted by "shear stress" in the skin, not by direct fore-aft forces, so that the stresses are not trying to "fold" the "hinge". > Granted, glass-glass is best; but, given the drawings I have > (following them again will result in the same situation) wouldn't > shaping the top glass in a smooth curve, with at least a 0.1" > glass-glass contact at the left, and max 1/8" thickness of flox > between the top and bottom skins at the 1/2" point (the rest is > styrofoam) be better than a glass hinge in the top skin? Don't think so - just not enough strength in the 0.1" g/g bond. Change your picture to: JOG ________ Canard Top |_......------ ____/ TE ---_ - _ Nose--> And you're set - see that the "JOG" is now at a precise 30 degree angle from the horizontal, rather than the otherwise indicated vertical :-). As Jeff said, filling this area is mouse nuts in the grand scheme of things, and your structure will be better. > ASCII sucks. Tell me about it :-). > Assuming that the 'D' is filled with foam, I am talking about filling > that little jog with flox in a taperd manner and laying the top skin > over the flox (single operation while the flox is wet). Yeah, that's what I was afraid you were proposing. Taper the foam to get a smooth "JOG", glass over that to get the full g/g bond, and then fill with micro. You'll find that this is not substantially different than what you have to do on all the wing, winglet and elevator T.E.'s anyway, since there's a large micro fill that occurs on the bottom surface anywhere there's the fishtail cutoff in the foam. -- Marc J. Zeitlin Email: marcz@an.hp.com From: lschuler@cellular.uscc.com Date: Mon, 08 Dec 97 14:52:29 -0600 Subject: Re[2]: COZY: Canard Bottom Help (fwd) (fwd) Marc wrote: >snip >Yeah, that's what I was afraid you were proposing. Taper the foam to >get a smooth "JOG", glass over that to get the full g/g bond, and then >fill with micro. You'll find that this is not substantially different >than what you have to do on all the wing, winglet and elevator T.E.'s >anyway, since there's a large micro fill that occurs on the bottom >surface anywhere there's the fishtail cutoff in the foam. Ok, I'm Sold! Sorry it took a sledge hammer... Did bottom layup Saturday. Will see how much of the 1/8" is left after flipping it over and chopping fish tail off. All I have been able to do so far is best-guess with tail still on and canard upside down in jigs. May not be able to get to it till after Xmas. Thanks for the structural engineering lesson. Seriously. The pop can idea helped to understand the nature of the torsional shear stress; but had no intention of leaving a gap suggested by cutting the can (seems a bit of an extreem relative to flox and tapered skin; but that's another discussion). This list is great! Larry Date: Sat, 20 Dec 1997 21:37:43 -0500 From: Ian Douglas Organization: WTC Subject: COZY: Shear Webs Hi All, Well we have a sheer web semi-completed, I say this because we did not trim the glass to the spar cap cutouts at the proper time (the proper time is BEFORE they f*&%ng cure). Any one that is going to do any layup, make sure that you do as much trimming as possible PRIOR to cure. I have spent over 10 hours trimming and am still not done (to my satisfaction and including the fabrication of the Dremel tool below). Since I was tired of trying to trim the glass (without messing up the spar cap slots and shear web glass AND wearing a wonderful glass dust) I made LWA2 and LWA3. I am assuming that I am to centre these hard points on the shear web (over hang LWA2) and then the spar caps are supposed to fill in the over hang (the drawings do show this where the 10lbs of weight is applied). I have taken the wing out of the jig and am flipping the jigs for the other wing layup next week. With all of the trimming required I did come up with a holder (made from wood and a hose clamp) for my Dremel that allows the blade to protrude 1/16" in a perpendicular cut (think of a table saw with the blade protruding 1/16" and a 90 degree corner at the blade) This allows me to slide the tool in the troff and then again perpendicular giving me back the troff minus glass. I made some drawings and am having an aluminum holder made by an AME friend, who has a number of bored machinists working for him, to finish the rest of the trimming (the wooden one allows the tool to slip/vibrate loose with time and I am afraid of hitting the glass that I want to keep). Hey Mark, does this get me in to the Oaf Apprentice Program? -- Ian MK0069 Date: Mon, 29 Dec 1997 10:03:19 -0600 (CST) From: Tom Brusehaver Subject: COZY: Ch 10. Canard questions I had to abort chapter 6, if I woulda glued the fuse together, I wouldn't have been able to get it out of my basement :-o. I jumped ahead to chapter 10, but have a zillion questions, and the archives maybe didn't answer all of them. 1. 4 inch nails! Well, are the plans asking for like 16 penny spikes? or would a plain old music wire work for that. It seems with a half dozen nails in there, the canard might be deformed from weight. 2. Marking the centers. Are you supposed to mark the center of the whole core, or the center of the shear web cut out? I think for alignment, it won't matter, but if you want the line to be straight, there might be a dihedral. 3. Lift tabs. Okey Nat has me scared on this. Um, if I scratch one, I'll stress it? Yikes, if they are that critical, why aren't there 4 of them? I could see building the whole canard, and while moving the sucker, bumping it into something, and scratching it like two years from now, would I have to rebuild the whole canard. (I think the f22 bulkhead is weaker than the aluminium lift tabs). 4. Shear web layup. It looks (and reads) like there are several layers over the top and bottom spar trough, but the picture only shows one BID layer. Why do the pieces have to be so wide? Probably more questions, but these are my big concerns now. From: lschuler@cellular.uscc.com Date: Mon, 29 Dec 97 11:45:12 -0600 Subject: COZY: Ch 10. Canard questions Tom Brusehaver wrote: >I had to abort chapter 6, if I woulda glued the fuse together, I >wouldn't have been able to get it out of my basement :-o. >I jumped ahead to chapter 10, but have a zillion questions, and the >archives maybe didn't answer all of them. >1. 4 inch nails! Well, are the plans asking for like 16 penny spikes? >or would a plain old music wire work for that. It seems with a half >dozen nails in there, the canard might be deformed from weight. I used 4" drywall screws. Much easier to keep straight etc. These are used to support the canard rear section(s) while laying up the shear web. >2. Marking the centers. Are you supposed to mark the center of the >whole core, or the center of the shear web cut out? I think for >alignment, it won't matter, but if you want the line to be straight, >there might be a dihedral. I believe you are refering to the straight line needed on the face of the shear web from one end to the other. It is necessary and it does matter. I believe Nat warns about the diference in taper from the tip to the center section. You also need to keep in mind that the top spar trough is deeper than the bottom trough. It all makes measuring and finding the true center a bit challenging. If done corectly, you should be able to stretch a string line from one end to the other and find the center line dead -on. >3. Lift tabs. Okey Nat has me scared on this. Um, if I scratch one, >I'll stress it? Yikes, if they are that critical, why aren't >there 4 of them? I could see building the whole canard, and while >moving the sucker, bumping it into something, and scratching it >like two years from now, would I have to rebuild the whole canard. >(I think the f22 bulkhead is weaker than the aluminium lift tabs). Scratches in aluminium are stress failure points. Blanket statement to be sure, but I think that is what Nat is trying to avoid here. If you are afraid of scrathing them -later- during handling, you can cover them with some sponge rubber and tape to protect them. >4. Shear web layup. It looks (and reads) like there are several >layers over the top and bottom spar trough, but the picture only >shows one BID layer. Why do the pieces have to be so wide? Not sure which picture you refere to, but 'ALL' the shear web layups (multiple UNIs and one BID) DO extend over the top and bottom spar troughs and get trimmed at the rear edges of the troughs (or even up to a 1/4" short of the edge as I recall). Read through it all again and even ahead a few paragraphs. It might become more clear. Hope this helps. Larry Schuler lschuler@cellular.uscc.com Date: Mon, 29 Dec 1997 13:29:40 -0500 From: bil kleb Organization: NASA Langley Research Center Subject: Re: COZY: Ch 10. Canard questions i forgot that i had composed this until i saw larry s's response, so have at another version of basically the same story... Tom Brusehaver wrote: > > 1. 4 inch nails! Well, are the plans asking for like 16 penny spikes? sure. whatever you use, you want it to withstand your squeeging when you do the shear-web lay-up. i used at least two dozen 16 penny finish nails (stuck at an angle--see note in figure 20) hot-glued to the_12-foot_ 2x4s. > 2. Marking the centers. make whatever marks you like to be sure your canard cores are straight, i.e, no dihedral or other "exotic" bends :) i marked the center of the shear web face on the center core, and inside edges of the inboard cores. then, i transferred the marks from the center core to the outside ends of the inboard cores by lining-up the airfoil shapes. (read 5 times) > 3. Lift tabs. i've heard many are scared by the 1/8" thick pieces and are going to 1/4" aluminum. as jean-jacques c has written, this, as well as larger AN6 bolts and 3/4" OD bushings for the attachment to F22, is a mandatory change for (european) cosys (and maybe even european long-ezes and cozys?). as far as scratches: any metal will see them as a stress concentration point and cracks will usually emanate from them if they are substantial (deep) enough. to a point, stress goes as 1/radius, and so a scratch produces very high, localized stress due to its extremely small radius. hence the method of "stop-drilling" cracks---increasing the crack's radius. in other words: don't take a nail and scratch your initials in them. ;) > 4. Shear web layup. It looks (and reads) like there are several > layers over the top and bottom spar trough, but the picture only > shows one BID layer. _all_ shear web lay-up glass, except for the 9 plies of bid over the canard attach nutplate inserts, goes "over the forward face of the aft pieces of the inboard and center canard sections and DOWN THE SPAR CAR FACES[.]" (last paragraph of page 10-3) in shorter terms, look at the cartoon drawing of figure 2 on page 10-1. the single layer shown in the figure represents the whole, 7-ply shear-web layup. > Why do the pieces have to be so wide? to cover the three sides mentioned above (front face, top spar trough, and bottom spar trough). -- bil From: "norm & monda" Subject: Re: COZY: Ch 10. Canard questions Date: Mon, 29 Dec 1997 16:55:27 -0500 we used small pieces of welding wire instead of the nails, you know how when a screwdriver slips out of the screw it scratches the metal or wood, this is the kind of scratch he is worried about, just sand them with 220 before you bond them in and all will be alright. and yes there are layers over the top and bottom of the spar trough thats why you have to cut the nose off using the hotwire and bond it back on and the dowels are to realign it to the proper position. norm From: cdenk@ix.netcom.com Date: Mon, 29 Dec 1997 19:53:41 -0600 (CST) Subject: Re: COZY: Ch 10. Canard questions Schuler writes <16d (Penny) nails ?> I seem to remember using 1/4" dowels, and removing them after aligning and gluing. I don't like the idea of leaving nails forever in the canard, they add weight and could vibrate and really rattle long term. Incidently I have 2 printed circuit on mylar VOR antennas in the bottom forward of the canard. Its kind of neat when doing a ground check I can align them exactly with the circle on the taxiway. Date: Tue, 30 Dec 1997 08:46:39 -0500 From: bil kleb Organization: NASA Langley Research Center Subject: Re: COZY: Ch 10. Canard questions cdenk@ix.netcom.com wrote: > > I seem to remember using 1/4" dowels, and removing them after > aligning and gluing. I don't like the idea of leaving nails > forever in the canard, they add weight and could vibrate and > really rattle long term. i don't understand this. as far as i know, no one said to leave any nails in the canard!? the nails we're talking about (i think?) are just temporary. they serve to hold the aft section of the canard trailing edge down between two 12' 2x4s so that the shear web layup can be done. the 1/4" dowels are "drilled" into the canard before cutting the canard at the shear web, removed to cut the canard for the shear web layup, and then re-inserted for aligning the front and back halves of the canard after the shear web layup is done. -- bil