Date: Thu, 18 Jan 96 11:08:52 EST Subject: Re: Canard questions Brian; >............. Did you >get longer that 8' 2x4's (it appears that way from your pictures)? I just butted a couple of extra pieces of 2x4 on the ends of the others. They're just for support - they don't have to be perfectly straight or anything, since you'll jig the canard straight anyway. >....... Do you >think if the ends of my canard hung out past the boards it would cause >problems (sagging)? Yes. Support it for sure. >...... I've about made up my mind to get a another board and >lengthen averything to 12', but can't understand why the plans would >indicate 8' boards would suffice! Because Nat made a mistake, and admits it - I just don't think a correction ever made it into the newsletter. >You mentioned that had you measured the cores against the template after >you sawed off the fishtail you could have avoided the problem. I take that >to mean that you probably carved the topside of the canard too low at the >aft end. Is my assumption correct? That is certainly ONE of the problems I think I have. Others say that the templates do have a problem, so it's certainly something to be careful about. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Thu, 18 Jan 96 08:52:00 PST From: Brian DeFord Subject: Canard questions Marc, I thought I would ask you this question alone since it is your WWW page that brought it up...I have cut the cores for the canard and am ready to jig them up for laying on the shear web. I got these two 8' long 2x4's on the table (according to the plans) and the canard is 12' long. Did you get longer that 8' 2x4's (it appears that way from your pictures)? Do you think if the ends of my canard hung out past the boards it would cause problems (sagging)? I've about made up my mind to get a another board and lengthen averything to 12', but can't understand why the plans would indicate 8' boards would suffice! One other question since I have your attention. The problem you had with the elevator is ingrained in my mind as something to be careful of. You mentioned that had you measured the cores against the template after you sawed off the fishtail you could have avoided the problem. I take that to mean that you probably carved the topside of the canard too low at the aft end. Is my assumption correct? Thanks for your help, Brian DeFord Date: Mon, 18 Mar 1996 21:04:43 -0500 From: MKansky@aol.com Subject: Chapter 10, page 6 figure 39 question I just completed the bottom skin on the canard and as I was looking over figure 39 I notice that I have the triangular gap on the aft side and not the forward edge of the canard. Does this make a difference? When laying up the top skin, should the gap be on the leading or trailing edge? Has anyone successfully layed the top spar cap and skin at the same time? If so, how long did it take? ...Marty Kansky N321CZ From: Michael Antares Subject: RE: Chapter 10, page 6 figure 39 question Date: Mon, 18 Mar 1996 19:41:48 -0800 I just completed the bottom skin on the canard and as I was looking over figure 39 I notice that I have the triangular gap on the aft side and = not the forward edge of the canard. Does this make a difference? When laying = up the top skin, should the gap be on the leading or trailing edge? Has anyone successfully layed the top spar cap and skin at the same = time? If so, how long did it take? ...Marty Kansky N321CZ In answer to the first part, it should not make any difference since you = add very shortly another piece of BID to fill in the missing area. In = answer to the second part I think there are some good reasons not to lay = the skin up at the same time, the main one being that there are = unavoidable depressions and raised areas in the spar cap layup caused by = the shortened layers. I was able to remove a lot of these (not all) by = sanding the spar cap before I did the top (and bottom) skins. I am sure = there are also some good reasons to DO the top skin at the same time but = I know I was pretty tired after finishing the spar cap (but nothing = compared to doing the top spar cap on the center spar (23 layers). And speaking of the canard--I just finished installing the elevators and = came across a couple of issues (a euphimism for not doing something a = better way!). First I had a problem getting the 15 degrees of up elevator and what it = turned out to be was not a conflict with the canard trailing edge but = the hinges bottoming on the slot of the CZNC-12A Torque Tube Offsets. = The plans don't provide an exact position of the offset when drilling = the #12 holes for the mounting bolts but had I positioned them just = slightly differently than I did, I wouldn't have had a problem. As it = was I filed the slot just slightly and was then able to get the 15 = degrees so it ended well. Secondly I found that with all four AN3 bolts loose (the ones that = secure the two offsets), it was possible to get a significant = misalignment of the two elevators--in other words the combined slop of = the four bolts in their respective slightly oversize holes allowed the = two elevators to rotate out of alignment. I am concerned that just = tightening the bolts is the total answer and I am inclined to install = four dowel pins in addition (perhaps 1/8") that will be a press fit = rather than the slop existing in the bolt holes. Has anyone else also = experienced this and/or any recommendations? Date: Thu, 1 Aug 1996 14:10:54 -0400 From: TMKPIDA@aol.com Subject: COZY: Verify lift tab size Good morning all! Verify that you have the correct lift tabs when it comes time to build your canard. Silly me went and drilled the top hole in the lift tab to 1/4" vs the #10 required. So it was off to Brock for another set (which by the way they only sell as a set, but that's another story). Got home, and LUCKY me, found them to have that hole drilled in the top already. How nice! ... and then I realized they were bent with oh, about 3/16th of an inch warp. So off again to Brock. While I was comparing the two sets of lift tabs at Brock, JUST then did we realize that the bent ones were SMALLER. Sorry to do this people, but it would probably be a reallly good idea to check your lift tabs to insure that you did not get the SMALLER LONG-EZ tabs by mistake!!!!! I sincerely hope that this was a one time mistake. Happy sanding. TMK #248 Canard construction. Date: Tue, 13 Aug 1996 09:43:59 From: JRaerocad@gnn.com (Jeff Russell) Subject: COZY: R1145MS with dihedral? Anyone wanting one of these funny looking dihedral canards on their Cozy or Cozy MKIV??? I am planning on making a new one for the AeroCanard to see what differences it makes other than it looks better? This canard is harder to build than the straight because we build on 2 I-beams. This will be impossible for a bent canard. I will mold the top skin inserting the spar and solid L.E and T.E. foam cores in the mold at one time vacuum bagging the bottom skin at one time. This will give paint ready top skins and peel plied bottom skins. (Quick build version) over you bond the cores to the spar and skin your selves. What do you think??? I will be trying this for myself first before I can tell you anymore. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com From: Marc J. Zeitlin Subject: COZY: R1145MS with dihedral? (fwd) Date: Tue, 13 Aug 96 11:54:48 EDT Jeff Russell writes: >Anyone wanting one of these funny looking dihedral canards >on their Cozy or Cozy MKIV??? I am planning on making a >new one for the AeroCanard to see what differences it makes >other than it looks better? Some might think it looks better; I think they look funny :-). To each his own. Ken Miller (who has dihedral in his canard on his Long Eze) says that he can't find any difference in performance with it - he just likes the looks. >This will give paint ready top skins and peel plied bottom skins. >(Quick build version) over you bond the cores to the spar and skin your >selves. I like the idea for a straight canard QB kit, and I guess for those that like the dihedral - go for it - have two different kits. -- Marc J. Zeitlin Email: marcz@an.hp.com From: Lee Devlin Subject: Re: COZY: R1145MS with dihedral? Date: Tue, 13 Aug 1996 11:39:38 MDT > Anyone wanting one of these funny looking dihedral canards > on their Cozy or Cozy MKIV??? I am planning on making a > new one for the AeroCanard to see what differences it makes > other than it looks better? I think that the improved looks are definitely a matter of opinion. I happen to like the looks of the straight canard better than one with dihedral. My guess as to why someone would put dihedral in the canard would be to improve the lateral stability of the plane. Vance Atkinson has already done this but I'm not sure of his results. I haven't seen a lot of people copying it, so that may mean that its benefits don't justify the additional effort. > What do you think??? I've already started on my canard, so I may not be representative. I think I'd invest in wing leveler before a new canard design since a leveler is likely to give the advantage of hands-off flying and provide other benefits such as GPS signal tracking. Lee Devlin Date: Wed, 21 Aug 1996 00:02:09 -0500 From: Larry Jansch Subject: COZY: Canard Time! Yep, I have put off mounting the speed brake actuator until later. Was getting WAY too frustrated locating the LB-18's on the brake. I've started working on the canard, using Jeff Russell's semi-prefab kit. Nice product, if you haven't seen it. Real nice! Two items: 1) There has been a steady trickle about mounting the elevators either too high or too low due to a common misinterpretation of the plans. I assume that this has been discussed to death and is in the archives? (Haven't looked there yet) 2) The canard top template F (page M-17) is noted in one of the changes that the angle must be changed "to agree with the top template on drawing M-18". Hah? I tried aligning the two templates against each other against a window pane to see if there is any change on the curved surface, but my CRT-ruined eyes did not see any difference. Anyone care to enlighten me? 3) Make that three items. I wholeheartedly support the idea of a virtual EAA chapter. I belonged to a local chapter in North Carolina that was mostly populated with tube-and-fabric butt dragger flyers. I couldn't take listening to the bash "them plastic deathtrap aera-planes" and talk endlessly about how great their first Taylorcraft was. I've read far more interesting discussions here and learned far more whilst skulking on the sidelines. And, it's been fun! Sign me up, guys. Where do I send the check? And, as always, thanks in advance! -Larry -- Larry Jansch Cozy Mk.IV Plans #461 Still in Ch. 9 Date: Wed, 28 Aug 1996 07:34:43 From: JRaerocad@gnn.com (Jeff Russell) Subject: COZY: Bent canard update The new mold for the bent canard is finished and a part has been made. I will next build a canard using this spar seeing if it's much harder to bond the leading edge and trailing edge cores on it. The strait one is EZ. I will finish it to paint ready and then pull a male mold off the top skin so I can mold a finished top skinned canard using solid foam cores and spar. This type of process is being done and being sold at Velocity as quick build wings and canard. The Velocity RG Elite used this type of wing and canard. No problems. I think that this new bent canard will be harder to attach the foam cores on the spar correctly and making a mold to do this will take out this problem. It will also take out filling and sanding the top skin of the canard because it will be paint ready because of the mold. I don't yet know what the pricing will be on a canard of this type. The canard chap. 10 complete is $1400.00 I will try to keep the price lower than $2000.00 We will see. Keep you updateded on the progress. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Thu, 03 Oct 1996 22:31:27 -0500 From: Larry Jansch Subject: COZY: Canard Twist I finally (yes, the gods of work have allowed me some free time) got the canard cores and spar put together. I was levelling it on the bench in preparation to skinning the bottom when I noticed that the one of the solid foam extensions is slightly (1/16-1/18") twisted. It looks like a classic case of internal stresses appearing after hotwiring. Nat, Jeff and the rest of you emphatically state that "any and all twist MUST be removed before ... etc, etc. Well, how DO you untwist it? I didn't find any references to it in my pile o' books. Use weights? Not on top of it if you're planning to skin it. I can't think of a solution that won't flex the canard, too. (Yup, I looked in the archives first.) My thanks... -Larry -- From: Marc J. Zeitlin Subject: COZY: Canard Twist (fwd) Date: Fri, 4 Oct 96 9:41:25 EDT Larry Jansch wrote: >Well, how DO you untwist it? I didn't find any references to it in my pile >o' books. Use weights? Not on top of it if you're planning to skin it. I >can't think of a solution that won't flex the canard, too. (Yup, I looked in >the archives first.) My thanks... Assuming you're jigging the canard on top of the plywood jigs, you should be able (with the jigs bondo'ed to the foam) shim the jigs so that the leading and trailing edges are perfectly straight and both ends are level. The bondo will allow the jigs to pull the cores down where needed. Another idea might be to screw a 3" drywall screw into the ends of the foam, and tie string to it to pull it down (haven't tried that one). -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Sun, 06 Oct 1996 14:20:19 -0500 From: Neil Clayton Subject: COZY: NC-3 Airleron hinge pieces Hi everyone...I'm making my own aluminium pieces vs buying them from Brock. The plans sketch the NC-3 hinge pieces, but the dimensions are a bit slim....hole spacing, etc. Could someone please lay a rule on one and let me know the dimensions? BTW - I found some small sealed ball-bearings at our local surplus store to use instead of the bronze bushings the plans call for as aileron hinge points. Should be pretty well frictionless. Thanks. Neil. by SERV05.SLAC.STANFORD.EDU (PMDF V5.0-6 #10979) id <01IAD94J5M24000L7P@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Mon, 07 Oct 1996 16:25:17 -0800 (PST) Date: Mon, 07 Oct 1996 16:26:42 -0700 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: COZY: NC-3 Airleron hinge pieces Niel Clayton said: BTW - I found some small sealed ball-bearings at our local surplus store to use instead of the bronze bushings the plans call for as aileron hinge points. Should be pretty well frictionless. Thanks. Neil. Be careful, here, Neil. Friction is not the only factor to consider. All aircraft tend to build up a static charge, in flight. This charge isn't evenly distributed over the wing, chordwise. This results in an electrical potential between, for example, the leading edge and the trailing edge. There can be a substantial difference between the alerion and the trailing edge of the wing itself, even on "good-conductor" aluminum wings. When this charge builds up sufficiently, arcs can occurr. This actually welded ball bearings together, before the effect was understood. The solution? A bonding cable between the movable surface and the non-movable wing trailing edge. I'm not sure if anyone truly understands what may happen with a non-conducting composite, in this regard, but I would be very cautious about just substituting a ball bearing here. Considering nearly everything is a dielectric, a bonding cable wouldn't do much good, in the traditional fasion. If the design is similar to Rutan's Long EZ, the bearing I believe you are talking about was called out as a simple hole in a piece of phenolic, on the EZ plans. I never liked that too much, either, because it was wearing out on flying planes, and getting sloppy. I found some really neat spherical, self-aligning teflon-in stainless bearings for this task. I believe they were made by a company named Pobco. If you like, I can look it up this weekend. When in doubt, always check with the designer when making any change to the plans, especially where the flight control system is concerned. -Howard Rogers A&P 2005148 Date: Fri, 15 Nov 1996 18:16:23 -0800 From: berkut@loop.com Subject: Re: dyhedrald canard Vance Atkinson put some in his on the theory that it would raise the canard tip vorteses (sp? vorteces?) above the strakes and wings and increase cruise speed, and increase roll stability. He says it didn't do much, if anything. > >I'm a new builder, working on bulkheads right now. There has been a lot of >discussion on air foils. I've noticed some Cozys with a dyhedral in the >Canard, but I've not heard or read anything about this modification. > -- Czech Sikhs! Richard Riley "The important things are always simple. The simple things are always hard." See the Berkut at http://www.berkut.com Date: Sat, 16 Nov 1996 20:13:24 -0500 From: Jim Hocut Subject: COZY: Vac Bag Canard???? Anyone figure out an acceptable method of vac. bagging the canard without the possibility of inducing any twist, etc. (short of borrowing someones Cozy and making molds)? Or am I going to be the pioneer in this? Jim Hocut jhocut@mindspring.com Date: 17 Nov 96 23:51:13 EST From: INFINITY Aerospace <72124.347@compuserve.com> Subject: COZY: Dear Pioneer Jim Hocut wrote: >Anyone figure out an acceptable method of vac. bagging the canard without the possibility of inducing any twist, etc. (short of borrowing someones Cozy and making molds)? Or am I going to be the pioneer in this? I have, and helped others, used the female foam core as the jigging tool to keep the canard, wings and winglets straight. The only thing I can think of concerning bagging the canard foam core is putting formica all around the base of the female foam core for the bagging to seal against and use the core as a jigging tool. Obviously the cores must be dead nuts straight to be the perfect jig, and the formica must be sealed against the foam core. Call if you wish to talk about any of the details. HTH. Infinity's Forever, JD Date: 17 Nov 96 23:51:16 EST From: INFINITY Aerospace <72124.347@compuserve.com> Subject: COZY: Canard Dihedral John Stagel wrote: >I've noticed some Cozys with a dyhedral in the Canard, but I've not heard or read anything about this modification.< A little dihedral (about 3" at the tip) will probably make the plane even more stable and possibly allow the canard vortices to mostly flow over the top of the wing during landing. It will be a little harder to build to get the dihedral equal on both sides, but not that bad. You'll have to talk to the builders who actually did the change to see how they did it and how they like it. As to whether they like it better than the straight canard and why, they would have had to of flown a straight canard for for awhile for comparison. HTH. Infinity's Forever, JD Date: Sun, 17 Nov 1996 23:55:08 -0500 From: Jim Hocut Subject: Re: COZY: Vac Bag Canard???? > >I know that Jeff Russell did a vac canard for a Berkut he was working on, >but he was using a molded spar to do it. Actually, I bought the canard kit (molded spar and pre-cut cores) from Jeff, so you've left a glimmer of hope. Jim Hocut jhocut@mindspring.com Date: Tue, 19 Nov 1996 13:29:39 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: Canard Dihedral Dewey Davis wrote: >I built a dihedral canard also. It was a little more trouble than >the original canard I built, but nothing that should deter you from >doing it if you want one. Vance has some nice plans for this. I >talked to three other EZ flyers that have done it and asked them if >there was any performance change. >The consensus seems to be, no. Vance thought he noticed some >slight roll improvement, but nothing to get excited about. Some people like >the dihedral look better, but thats about the only reason to do it. I also like the look of the dihedral in the canard better and new that it would be harder to build than the straight one. For this reason I took on making the job of building it out of a mold insted of from a set of plans. I first built a mold for the spar. Then built one from Vance's plans using lots of jigs to hold it for skinning. I video taped the process for others to see if thay would also like to try building it the same way. I then finished the top of the canard for paint and made a mold from the top of the canard. I also show the finishing and filling on the same video tape. I made the first molded bent canard and the weight was 4 lbs lighter than the one I made first. I vacuum bagged the top and bottom skins and spar giving this weight savings. It will also be lighter because of no fill on the top skin. I am about to change my straight to the new bent one ASAP. Those who want to build this kind of canard, I am willing to sell it 2 different ways. 1) Molded Spar for $475.00 Leading edge and Trailing edge cores with ends $175.00 ** This is for the build it your selfers. 2) Molded canard with top skin in primmer (paint ready) bottom skin ready for filling and finishing. $2000.00 ** This is for I want it now, so I don't have to build it person. I will some day build molds for both left and right top skins for the main wings and offer them the same way. The Video cost 15.00 + 3.00 for postage if you want to see this. Hope this helps AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com NEW homepage address: http://www.binary.net/aerocad Date: Wed, 20 Nov 1996 20:56:17 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: Vac Bag Canard???? Jim Hocut wrote >I know that Jeff Russell did a vac canard for a Berkut he was >working on, but he was using a molded spar to do it. Yes, We used a carbon spar that was molded at the AeroCad factory. >Actually, I bought the canard kit (molded spar and pre-cut cores) >from Jeff, so you've left a glimmer of hope. Only the top and bottom skins were vacuum bagged. In order to do this you will need to skin the bottom with a full bag all the way around it and close it using tape or dumb - dumb. You must use peel-ply, perf mylar, and (something) to press the excess resin into. The hardest part to vac-bag a wing or canard is lifting it out of the jig and placing the bag around it and sealing it off and getting it back on the jig in the blind with no twist. Spaning plastic on the skin will cause the fiber glass skin to pull off the core. I have always told people that vac- bagging wing/canard are a pain in the ass. Yes you can save weight but, you can end up with a mess. Also the weight will cost you time and money. If you save 4 lbs in resin and it cost about $100 in bagging material and a extra 1 hour per skin. What did the 4 lbs cost per lb? Vac- bagging works better in a mold. Too much can go wrong if you have never tried this before. You must also limit to bout 8 -11 inches of pressure or you will hav a speed wing after you are done. Hope this helps AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com NEW homepage address: http://www.binary.net/aerocad Date: Wed, 20 Nov 1996 22:10:19 -0500 From: Jim Hocut Subject: Re: COZY: Vac Bag Canard???? > >Also the weight will cost you time and money. If you save 4 lbs in resin >and it cost about $100 in bagging material and a extra 1 hour per skin. Well, actually I think it would be more like $10 worth of materials and an extra 10 hours per skin . Here are my thoughts, someone who's been there before please shoot me down on them: Bondo my 2 straight edges to my worktable so that I've got a good reference for a straight canard etc. Bondo a 1X6 (or whatever I've got) to the table in front of the straight edges so that I've got a good reference for placing the canard properly on the 2 straight edges. Do the layup (only one side at a time). The "bag" will already be laying under the canard before I start the layup. Once the layup is done pull the bag around the canard making an envelope and seal it up. Set the "envelope" and it's expensive contents on the two straight edges. Pull the bottom skin of the envelope tight so that the package will sit evenly on the straight edges, then apply vacuum. Evenly distribute small weights over the upper surface to hold everything in place. IF this will work OK it won't be too terribly difficult and won't cost all that much. I realize there's only a limited weight savings potential on the canard, but I look at this as a test bed for the wings, where I'm sure there is much more potential for weight savings. OK, GO AHEAD AND SHOOT ME DOWN, I CAN TAKE IT. Jim Hocut jhocut@mindspring.com Date: Wed, 20 Nov 1996 22:10:11 -0500 From: Jim Hocut Subject: Re: Re[2]: COZY: Vac Bag Canard???? Larry Schuler wrote: > > > Molded spar.... I don't have any idea waht it looks like or > attachement method; hope you can help with a couple questions. > > Is the spar essentially shapped per the layup schedule in the plans? As far as I can tell it is exactly per the layup schedule in the plans. You just essentially glue leading edge and trailing edge cores to the spar and you're off to the races. > > Is spar vac bagged? I'm not sure... Jeff ?????? > Any reason it may be easy enough for a builder to make a simple mold > similar to the main spar forms and make a separate canard spar? Would > that make too much work or allow for some more accurate trimming > before the spar is glued to the core? > I wouldn't want to even think about what would be invlolved in doing all that unless I planned on building dozens and selling them. The problem I see with that is that Jeff has a 4 or 5 year head start on the rest of us. Jim Hocut jhocut@mindspring.com From: "Krasa, Paul" Subject: RE: COZY: Vac Bag Canard???? Date: Thu, 21 Nov 1996 03:19:39 -0500 JRaerocad@gnn.com writes > >Only the top and bottom skins were vacuum bagged. In order to do >this you will need to skin the bottom with a full bag all the way >around it and close it using tape or dumb - dumb. You must use >peel-ply, perf mylar, and (something) to press the excess resin into. > >The hardest part to vac-bag a wing or canard is lifting it out of >the jig and placing the bag around it and sealing it off and getting >it back on the jig in the blind with no twist. Spaning plastic on the >skin will cause the fiber glass skin to pull off the core. I have >always told people that vac- bagging wing/canard are a pain in the ass. >Yes you can save weight but, you can end up with a mess. OK this is great, but what is the bagging schedule? Once the part is layed up do you go peel ply, bleeder cloth and then ports and bag? or is there some other bagging schedule that will give wou a good surface without creating a resin lean part, wrinkles, etc.? > > >Too much can go wrong if you have never tried this before. You must >also limit to bout 8 -11 inches of pressure or you will hav a speed >wing after you are done. I had guessed that vacuum pressure needed to be limited. How did you come up with 8-11 inches? Paul Krasa Long EZ 214LP !---*---! > > Date: Thu, 21 Nov 96 08:48:54 est From: "Larry Schuler" Subject: Re[2]: COZY: Vac Bag Canard???? Jeff Russell wrote: >snip> >Too much can go wrong if you have never tried this before. You must >also limit to bout 8 -11 inches of pressure or you will hav a speed >wing after you are done. Jeff, What's a "speed wing"? Do you mean 8 to 11 Lb per sq in pressure on the bag or is it 8 to 11 in Hg of Vacuume on the guage? Larry Schuler MKIV-#500 Date: Fri, 22 Nov 1996 10:30:55 From: JRaerocad@gnn.com (Jeff Russell) Subject: RE: COZY: Vac Bag Canard???? "Krasa, Paul" writes: >OK this is great, but what is the bagging schedule? Once the part >is layed up do you go peel ply, bleeder cloth and then ports and bag? >or is there some other bagging schedule that will give wou a good >surface without creating a resin lean part, wrinkles, etc.? Once the part is layed up, add peel ply, perf mylar, bleeder cloth and then seal the bag? You could also add screen mesh between the mylar and bleeder cloth to keep skin wrinkles down to a min. >I had guessed that vacuum pressure needed to be limited. How did >you come up with 8-11 inches? This is what the Berkut factory told us to use. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com NEW homepage address: http://www.binary.net/aerocad Date: Fri, 22 Nov 1996 09:18:11 -0800 From: berkut@loop.com Subject: RE: COZY: Vac Bag Canard???? >I had guessed that vacuum pressure needed to be limited. How did you >come up with 8-11 inches? > >Paul Krasa >Long EZ 214LP !---*---! >> Much more than that and the foam starts crushing and distorting. -- Czech Sikhs! Richard Riley "The important things are always simple. The simple things are always hard." See the Berkut at http://www.berkut.com Date: Mon, 25 Nov 1996 16:11:35 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: Pre fab skins Steve Blank wrote: >I am unsure of how you mold a canard wing with the skin in >place. Could you explain how you place the glass in a mold >and get tight contact to the foam? First of all a good fit with the foam cores and spar must be right. I will bond the cores to the spar in the skin mold and let cure. Next I will drill 1/16" holes through the L.E. and T.E. cores for the excess resin to pull through to the bottom skin. These holes are about 2 inches apart. I will also cut the T.E. cores without the extra foam support having only a knife edge T.E. I will next insert the high density foam inserts and let cure. Now I am ready to skin the canard. Epoxy primer is sprayed into the top skin mold and let air dryed until tack free. The top skins are then wet out in the mold with the L.E. overhang left dry. Then the bottom skin is layed up and the L.E. overhang is folded over the bottom skin and finished wetting out. Add all the vacuum bag stuff and bake at 120 degrees. >And exactly what will a builder get if I buy an upper wing >skin? How is it used, lots of filler and my core, or is there >some way to control the fit? If the cores show wire lag or are undersize then hard shelling would need to be done for a good fit while under vacuum in the mold. If this were if this was not done, then the skin would not bond to the foam cores and WE WOULD NOT BE HAPPY. >(sounds like good ideas, i am just short of the complete picture >in my head.) Is the final product the same as what I would build >or are there different structural components? The same thing but if there was a need for fill to get the right shape for the top of the canard the fill would be under the skin. Hard shelling (can not) be done over the spar. That's why a molded spar must be used to get the right shape in that area. >I am very interested in your new canard with dihedral, and will >probably get this from you after testing and flight evaluation. >E-mail if you have time, or we will talk in person some time..... AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com NEW homepage address: http://www.binary.net/aerocad Date: Fri, 06 Dec 1996 20:43:01 -0500 From: Nigel Field Subject: RE: COZY: Aluminum/Composite At 05:08 PM 12/6/96 -0500, Nick Ugolini wrote: >After seeing the stength of the landing gear hardpoints (I broke my carbide >router bit on them), I wonder if anyone has considered replacing the Al with >a builder fabricated sheet (vice a purchased carbon fiber sheet)? The >builder could do a wet layup of 15 or so layers of glass, on a flat surface, >let it cure, then cut the necessary elevator parts out. You could even >place a piece of teflon or stainless steel tubing at the pivot point to >reduce wear. I have had good results with glass/epoxy hinge points on my VE Roncz canard elevators. These were made 6 years ago by laying up a construction sheet of uni/bid mixture about 3/32 in think then cutting it into tabs and burying it into the elevators with flox and adding 2 outer plies per side of bid laping onto the elevators. The hinge bearings are bronze oilite bushings pressed into holes in the tabs with a C clamp and JB weld epoxy. The torque tubes are helical glass made with 3 wraps of + - 45 deg bid over a 1 inch round foam core rolled like a cigar on plastic sheet and re-inforced at an imbedded aluminum slug at the control arm attachment. Its much stiffer in torsion and about half the weight of alumunum. My cozy elevators are done the same way. The VE hanger brackets are however 1/8 aluminum but after reading about the corrosion problems others have seen, I think this winter I will remove one ( like the propane torch approach) and see if its corroded. I have no hesitation in replacing it and possibly all the others with glass. I have another glass hinged elevator that I scrapped when the primer got through the skin and ruined the core. I have occasionally demonstrated the strength of the hinge points by looping a piece of 1/16 steel cable through ONE hinge bearing and over a floor joist and then lifting my 170 lbs off the floor with it. I showed this to George Graham when he visited last year and I think he was planning to do his the same way, did you George? Nigel Date: Sat, 7 Dec 1996 07:56:33 -0500 (EST) From: "George A. Graham" Subject: RE: COZY: Aluminum/Composite On Fri, 6 Dec 1996, Nigel Field wrote: > > I have had good results with glass/epoxy hinge points on my VE Roncz canard > elevators. The VE hanger brackets are however 1/8 aluminum but after > reading about the corrosion problems others have seen, I think this winter I > will remove one ( like the propane torch approach) and see if its corroded. > I have no hesitation in replacing it and possibly all the others with glass. > I have another glass hinged elevator that I scrapped when the primer got > through the skin and ruined the core. I have occasionally demonstrated the > strength of the hinge points by looping a piece of 1/16 steel cable through > ONE hinge bearing and over a floor joist and then lifting my 170 lbs off the > floor with it. I showed this to George Graham when he visited last year and > I think he was planning to do his the same way, did you George? > Nigel Alas, No. It does look good, and I was verry tempted, but I chickened out, and made aluminum pieces per plans except for the inner hinge brackets, these are made from 1/4" thick phonelic, with a large hole to accomodate my offset torque tube weldment. I am hoping to avoid the cold feet. I also failed to treat and paint the torque tube itself, as recommended in a Canard Pusher. I'll have to watch the whole thing, or maybe replace it. If I do it over, it will be exactly like yours Nigel. I just didn't have the courage then. BTW, I read that the best way to make a glass tube, is to wrap a plastic pipe, then blow through it with a warm hair dryer (makes it swell), then you can slide it off the pipe when setup and cool. George Graham Eracer #206 Mazda Rotary Engine (716) 874-3277 Date: Thu, 26 Dec 1996 09:22:51 From: JRaerocad@gnn.com (Jeff Russell) Subject: COZY: Bent canard update Keeping you updateded on the progress. I flew the new canard yesterday and saw better roll. Stalls seem to be about the same and speed has not been checked yet. I added a extra NC-3 hinge at the center close to the pitch trim. The only thing I need is a stronger spring and I think I will have a winner. The price for the molded bent canard will run $2000.00 because of the vacuum bagging. I will also sell just the spar and foam cores for $470.00 for spar and $185.00 for the cores. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com NEW homepage address: http://www.binary.net/aerocad