Date: Mon, 16 Feb 1998 08:51:32 -0600 From: Darren DeLoach Subject: COZY: Re: Made a mistake on bulkhead, how should I fix? Just a quick followup to my note from last week on my UNI layup mistake on the aft LG bulkhead, this was Nat's reply and I did exactly as he requested as my solution. >Dear Darren, >Sorry you didn't understand the intent of the designer. Forget about the >unnecesary layups in the middle. They won't hurt a thing, and the extra >weight is insignificant. On the sides where you don't have the correct >orientation, they might be okay, but I would suggest adding 2 extra layers >on top with the correct orientation. The extra weight is insignificant, but >the extra strength would make me feel better. Regards, Nat > -- Darren DeLoach Sales & Software http://www.deloach.com From: "L. Wayne Hicks" Subject: COZY: Foam Edge-Gluing Technique Date: Fri, 29 May 1998 10:01:28 -0400 Gang: Before I started my project, many of you said that the hardest part of building is figuring out the best "techniques" for doing things. What could be harder than edge-gluing foam sheets together? It took three tries to "perfect" my edge gluing technique, which hopefully will be helpful for new builders. My first try was on the 3/4" blue PVC foam for the seatback. I put down some plastic on my workbench, mixed up the 5-minute glue, applied sparingly to one edge, then hurriedly threw the panels together edge-to-edge. Sparingly is the appropriate word...I didn't use enough glue (first time, didn't want to use too much glue...). Although the foam is together with an acceptable bond, there are thin gaps that I will have to fill with micro before glassing. I also realized that the edges "out of the box" aren't exactly straight. So I learned right off the bat to confirm straight edges, sand if they're not, sand both edges until they match, etc. The second attempt was on the 0.2" clark foam for the IP, F22, and F28. Since the edge is so narrow, I didn't want to apply the glue to the edge for fear that the glue would run down the sides. So, I laid both pieces of foam edge-to edge-on the plastic, but spread apart by 1/2". I troweled the glue in the gap, then squeezed the pieces together. I had applied masking tape to the flat sides adjoining the edge so that when the excess glue oozed outward from the gap, all I had to do was remove the ooze and then quickly pull the tapes off. Nice clean joint...on the top. Unfortunately, some of the glue slid under the foam pieces. So I now have to sand the excess off. Third time was the charm. Prior to gluing, I flipped both pieces over, butted them together, then ran one length of masking tape (I ran out of duct tape) over the seam to form a hinge. I carefully turned the pieces over. Lifting at the hinge, I stood the panels up into an upside-down V with the now-opened "hinge" facing upward. By standing the pieces on edge, the pieces were still joined together at the hinge, and I now had a wider surface area on which to pour the glue without fear of it running under the pieces. I mixed and poured the glue onto/into the seam, spread it around really good, then pulled on one side of the panel. Voila. The panels fell flat onto the table, the excess glue squeezed out of the "hinge", the pieces stayed taped together, so the edges were very tight. I then squeegeed the excess glue off (very little excess this time), and pulled the top tapes off. Very clean. No clean-up and no sanding. Fun stuff! I will do this technique from now on. From: cdenk@ix.netcom.com Date: Fri, 29 May 1998 14:07:01 -0500 (CDT) Subject: Re: COZY: Foam Edge-Gluing Technique After edge glueing, of whenever need a flat foam surface with something harder (micro or flox) that need to remove, use the dremel with the router base and a flat disc stone. Set the stone flush with the base. Use the slot in the base to straddle the high spot. Can be used on curved surfaces with care also. Date: Sat, 06 Jun 1998 18:27:13 +0200 From: Jannie Versfeld Subject: COZY: Cozy MK-IV F28 Profile In the plans one has the option of making F28 more rounded. Can anyone tell me which option gives a smoother nose profile and what the advantage is? Jannie Verfseld Cozy builder #673 Date: Mon, 08 Jun 1998 07:41:17 +0200 From: Rego Burger Subject: COZY: COZY MK-IV F28 Profile >From my point of view it is purely aesthetic.... by rounding it you can make the top of the nose area rounder which would be every so slightly more aerodynamically efficient. Tubes are "cleaner" than squares. The nose (point) shape itself is not totally dependant on this change but it is best to flare the hole nose area once all the bits are in place to avoid any irregularities. I made mine about 1" higher in the centre and this did not make it too round on top at all, it did break that FLAT boxy look though. I chose a pointed nose (my taste) but some go for a round nose...I guess it's all up to you. Rego Burger, web site: http://home.intekom.com/glen/rnb.htm (home e-mail) mailto:rnb@intekom.co.za RSA Date: Wed, 17 Jun 1998 22:56:00 -0400 Subject: COZY: Ch 4 - Connecting foam boards for bulkheads From: dhill36@juno.com (Dana Hill) Hi Cozy Builders: Here's an easy one, if someone has a moment I need a clarification: Ch3, pg.4 states to use 5 minute epoxy for joining foam board while ch3, pg 5 states to only use micro slurry. The 5 minute seemed to work well but it's use is probably a heavy method. Comment? Note: Once I finish categorizing all my archive copies I probably won't have to ask a question like this. One other question to the group: I would like to know if anyone has determined if the newly available German epoxy is suitable for use in the strakes ( ie. compatibility with fuel)? Reference info discusses using it for many years to construct gliders in Europe and this has triggered this question. Thanks, ________________ Dana Hill COZY, Ch 4 dhill36@juno.com _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866] Date: Thu, 18 Jun 1998 13:30:42 -0500 From: Darren DeLoach Subject: Re: COZY: Ch 4 - Connecting foam boards for bulkheads >y one, if someone has a moment I need a clarification: Ch3, >pg.4 states to use 5 minute epoxy for joining foam board while ch3, pg 5 >states to only use micro slurry. The 5 minute seemed to work well but >it's use is probably a heavy method. Well, with the micro you'd be waiting half a day or more before you had a chance to do anything useful with the foam. With the 5 minute, you're able to glue then work almost immediately (well, 5 minutes....) You're not really using much of the stuff so weight is not really a consideration on the bulkheads. It might be more significant on the wings and canard, though. -- Darren DeLoach http://www.deloach.com Chap. 7 From: cdenk@ix.netcom.com Date: Thu, 18 Jun 1998 16:14:50 -0500 (CDT) Subject: Re: COZY: Ch 4 - Connecting foam boards for bulkheads I have made 5 minute micro slurry, and even flox (for not very critical locations). Strength wise the foam will be weaker than any epoxy mixture. When gluing foam you might mask the sides to minimize material to leave a hump. To remove the hump, use a dremel router base, a flat stone set flush with the bottom of the base. Date: Thu, 18 Jun 1998 15:47:21 -0800 From: hrogers@slac.stanford.edu (Howard Rogers) Subject: Re: COZY: Ch 4 - Connecting foam boards for bulkheads >I have made 5 minute micro slurry, and even flox (for not very critical >locations). Strength wise >the foam will be weaker than any epoxy mixture. When gluing foam you might >mask the sides to >minimize material to leave a hump. To remove the hump, use a dremel router >base, a flat stone set >flush with the bottom of the base. The above methods work beautifully, and I have done exactly the same, many times. For a seam that is too large to mix up 5 minute and do the whole thing, I have also done the following: You can mix up regular micro mixture and spread it on your foam edges, leaving a few "bare spots". Into these, go the 5-minute and micro mixture, deliberately mounded up a bit higher than the surrounding micro. When you bring the two surfaces to be bonded into contact with each other, the 5-minute hits first, then as you squish the parts together, the other micro flows in around these blobs, so there are no voids. Masking the edges is extremely useful, and saves a bunch of hassle and time. I scrape the 5-minute areas off with a flattened wood stirring stick, to level them, wait a few minutes, then scrape off the rest of the micro that has squeezed out of the joint. The whole thing is nicely tacked together now, and a secondary joining can take place, if that is the type of part you are building. I found this technique particularly useful while installing the baffles in the fuel tanks. The five minute would hold the ribs in place so nicely, I could fillet and add the bias tape while the original joint was still uncured, saving a whole step and a lot of prep. I wish I had learned it sooner, because there are several other places I could have used it! --Howard Rogers, 650-926-4052 hrogers@slac.stanford.edu Date: Tue, 23 Jun 1998 13:49:40 -0500 Subject: Re: COZY: Ch 4 - Connecting foam boards for bulkheads From: mikefly@juno.com (Michael B Bowden) On Thu, 18 Jun 1998 15:47:21 -0800 hrogers@slac.stanford.edu (Howard Rogers) writes: >>I have made 5 minute micro slurry, and even flox (for not very >critical >>locations). Strength wise >>the foam will be weaker than any epoxy mixture. When gluing foam you >might >>mask the sides to >>minimize material to leave a hump. To remove the hump, use a dremel >router >times. For a seam that is too large to mix up 5 minute and do the >whole >thing, I have also done the following: You can mix up regular micro >mixture and spread it on your foam edges, leaving a few "bare spots". >Into >these, go the 5-minute and micro mixture, deliberately mounded up a >bit >higher than the surrounding micro. In additional to the above methods, I have used a Dremel to remove excess cured micro leaving a shallow grove at the joint. The grove was filled with liquid urethane foam, sanded flush, leaving an almost perfect surface for glassing. mbb _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866] From: "L. Wayne Hicks" Date: Fri, 26 Jun 1998 08:51:53 -0400 In Chapter 4 on the firewall pieces, you flat-side the heads of the bellcrank screws (?? I don't have the plans in front of me) before embedding in flox to prevent them from turning later on way down the line. Have any of you had these screws break free and start turning when you tried to torque down the nuts? This happened to my friend and me when we installed the rudder bellcranks on his Long-EZ. The screw heads are not accessible, long since buried between the firewall and the aft end of the fuselage. It's a mess and a pain in the asp to slot these screws. I was thinking that I'd take the screws and the hole pattern down to my friendly machine shop and have them spot weld the screw heads to a small, thin aluminum strap. Once installed, they couldn't turn. Thoughts? __________________________________________ L. Wayne Hicks SpaceTec, Inc. Program Manager 3221 North Armistead Ave. 757-865-0900 voice Hampton, VA 23666 757-865-8960 fax http://www.spacetec-inc.com From: "Marc J. Zeitlin" Subject: COZY: rudder pulley attach screws in firewall Date: Fri, 26 Jun 98 10:05:34 EDT Wayne Hicks writes: >Have any of you had these screws break free and start turning when you >tried to torque down the nuts? I believe it's happened to some people. >I was thinking that I'd take the screws and the hole pattern down to my >friendly machine shop and have them spot weld the screw heads to a small, >thin aluminum strap. Once installed, they couldn't turn. I have purchased a number of PLAIN nuts and some locktite. I'll be using double nuts (regular and a jam nut) with locktite on both. This will allow me to tighten the nuts without the extra torque of the deformed metal nut (which is what will spin the screw). I figure with the jam nut and locktite, they're not going anywhere. I'm not an expert on welding (in fact, I don't know the first thing about it), but I'd think you'd need a steel plate to weld the steel screws to, not an aluminum one. Otherwise, that idea seems reasonable, too. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Fri, 26 Jun 1998 10:25:04 -0400 From: Paul Krasa Subject: COZY: Re: > >Have any of you had these screws break free and start turning when you >tried to torque down the nuts? This is a design flaw that everyone at one point or anouther experiences. In other words, I have had the same problem. > >This happened to my friend and me when we installed the rudder bellcranks >on his Long-EZ. The screw heads are not accessible, long since buried >between the firewall and the aft end of the fuselage. It's a mess and a >pain in the asp to slot these screws. Mr. Dremel Tool works great with a cut off wheel for sloting the screws. Once slotted use standard 10-32 non-locking nuts to hold the bellcranks in place. Tighten the non-locking nuts using a screwdriver to hold the stud from turning then place a standard 1/4 inch drive aircraft nut on the stud to act as a lock nut. Paul Krasa Long EZ 214LP From: lschuler@cellular.uscc.com Date: Fri, 26 Jun 98 11:20:07 -0600 Subject: COZY: Re: Chapter 4, Firewall imbedded screws Wayne Hicks wrote: >snip >Have any of you had these screws break free and start turning when you >tried to torque down the nuts? >snip Wayne, FWW/FYI: I stuck a subject on this return. Marc needs the info for archiving. Do check the archives. There are cases of the screws turning. For those who have the imbedded screws, but not attached anything yet (like me), about the only preventive medicine is to run the nuts on a separate screw once or twice before installing them on the firewall. This will help reduce the self-locking resistance and tendancy to spin the screws. Self locking nuts 'should' be good for several re-uses without defeating the purpose. Alternative may be using standard nuts with second jam nuts. I've seen this double-nut set up vibrate loose in other applications though. Mine were imbeded before I found out about this problem, so I must live with it. Maybe someone who hasn't attached the lower firewall can come up with a better mouse trap and send it to Nat for a change in design. Hope the info helps. Larry Schuler MK-IV plans #500 lschuler@cellular.uscc.com Date: Thu, 02 Jul 1998 12:32:32 -0400 From: "Johnson, Phillip" Subject: COZY: Re: Chapter 4, Firewall imbedded screws Larry Schuler writes: snip>Maybe someone who hasn't attached the lower firewall can come up with a better mouse trap and send it to Nat for a change in design. >Wayne Hicks wrote: >>snip >>Have any of you had these screws break free and start turning when >you >>tried to torque down the nuts? >>snip > I didn't use screws on imbedded installations. I counter bored the firewall bulkhead and used AN bolts with plenty of flox in the counter bore around the hex head. They have never hinted at turning. mbb _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866] From: "L. Wayne Hicks" Subject: COZY: Chapter 4 Synopsis for Cozy #678 Date: Fri, 10 Jul 1998 11:15:57 -0400 Gang: I'm basically finished with the Chapter 4 bulkheads. I haven't finished the firewall pieces yet. I need to purchase chemicals for the firewall aluminum inserts and I haven't settled on a method of attaching the blind AN screws for the rudder cable pulleys. I may weld the heads of the screws to a small triangular plate. Some of you suggested using nutplates. I know that I do not intend to just epoxy/flox the heads. We had trouble with the screws turning on my friend's Long-EZ. Here are my bulkhead weights. (Marc Z--> please feel free to include them on your website): F22 2.09 lbs F28 0.675 lbs IP 3.75 lbs Seatback 4.86 lbs FWD LG Upper 0.70 lbs FWD LG Lower 1.32 lbs AFT LG 2.52 My chapter build time stands at ___ hrs. (pending completion of the firewall pieces). I didn't have any trouble understanding the plans once I took the time to really read them and correlate the words to the figures. (Thanks, Nat.) The archives helped to answer some techniques questions, whether to use flox or dry micro for the radii on the IP rib stiffeners, and where to drill the LG holes. Some do's: 1. I did find it easier to glue foam edges together using the "hinge" method that I posted a few weeks ago, the one in which you use box tape across the bottom seam, box tape on the top edges of the seam, "bend the hinge" and put the 5-minute glue in the exposed hinge area, then return the foam flat. Wipe off the glue that oozes out, pull up the seam edge tapes. As soon as the glue sets, flip the foam over and remove the seam tape. 2. Thanks to the guy who posted the idea about pouring flox, 5-minute glue, or whatever into the corner of a sandwich bag, cutting the corner, then using it like a cake icing tool. This works extremely well for controlling the flow and coverage of the fluid onto whatever surface. 3. Do watch the Rutan video on composite construction techniques. It'll save you time and worry. I've never worked with peel-ply before and the video tape helped alot. Some don'ts: 1. Don't use a fiberglass roller unless you know what you're doing. You're only reward will be testing your ability to fix air pockets. My longerons are done, the fuselage side jigs are installed on my work bench, and I'll glass the sides this weekend!! __________________________________________ L. Wayne Hicks SpaceTec, Inc. Program Manager 3221 North Armistead Ave. 757-865-0900 voice Hampton, VA 23666 757-865-8960 fax http://www.spacetec-inc.com From: "L. Wayne Hicks" Subject: COZY: Whoops! Forgot to include Chapter 4 Build Time Date: Fri, 10 Jul 1998 11:23:24 -0400 My Chapter 4 build time stands at 60 hrs pending completion of my firewall pieces. __________________________________________ L. Wayne Hicks SpaceTec, Inc. Program Manager 3221 North Armistead Ave. 757-865-0900 voice Hampton, VA 23666 757-865-8960 fax http://www.spacetec-inc.com Date: Mon, 31 Aug 1998 23:33:02 -0400 From: "Marc J. Zeitlin" Subject: Fwd: COZY: Intrument panel stiffeners ribs and other Qs Chris Martin writes; >My question is: to flox corner or not to flox corner?. In the instrument panel >stiffeners, were the two lay-ups come together at 90 deg, should I flox corner >this area?. Generally, flox corners are only used where you will dead end a layup and not have glass to glass bonding (although that's not ALWAYS the case) and it's a structural joint. In this case, a flox joint is not required. The small bit of BID from either side that comes up vertically is only there to form a channel for cables and such. It adds a small amount of strength to the IP and stiffeners, but flox isn't required. >I also got an air bubble at one place at the top radius on the 2 BID side. I >tried hard to make it lay down but to no avail. I had enough radius but I >wonder if the radius is not consistent whether this could cause the fibers to >separate slightly. Is this something I'll have to deal with often are this >ribs particularly tricky?. If the radius is small, the BID will lift. This will occur occasionally - the NACA scoop and around the longerons are common areas, although there are others. You can use the instructions in Chapter 3 (or 25)? for repairing problems - in this case, just grind away the glass over the bubble, fill with micro, and glass over it. Or ignore it - in THIS case, it's pretty meaningless. >One last question. A couple of weeks ago I got a slight burning sensation in >my forehead and checks after doing a lay-up. No rash and no redness but it was >noticeable....... I use gloves and ply9 cream. I haven't used a >respirator although I'm also correcting that. Is a slight skin reaction from >over-exposure to the epoxy normal or is this a sign that I should stop >thinking I'll be able to build this airplane because of epoxy sensitivity?. Check the archives for epoxy info and protection info - there have been many discussions on this topic. This may be an epoxy reaction. You should NOT use cream and gloves - I think the cream instructions clearly state that. Use cotton liners, Butyl gloves, and latex or vinyl gloves over the butyl. Throw away the vinyl gloves after each layup. Use a respirator or carbon filter mask for all layups. You WILL eventually become sensitized to the epoxy. It may happen in the first couple of months; it may happen on your seventh plane (which you never get to) but it WILL happen. Protect yourself accordingly. -- Marc J. Zeitlin                     marcz@burnside.ma.ultranet.com 3 Sweetbriar Way                  http://www.ultranet.com/~marcz Acton, MA  01720                 http://cozy.canard.com/ From: Kyle Henderson Subject: COZY: Ch 4. G-10 Date: Fri, 4 Sep 1998 09:47:46 -0400 Hello, I've read that people have been using G-10 in the landing gear bulkheads instead of making their own 22 layers of fiberglass, so I thought I'd check it out. What I received from a plastics supplier was billed as "PHEN FR-4 .250". I called to confirm it was G-10 and they said it's actually called G-10 FR-4. I'm wondering if anyone else can confirm this from experience. (You can never be too sure.) What suprised me (and makes me question the material) is how easy it is to cut with a sabre saw, using a carbide grit blade. Kyle Henderson From: Greg and Jill Hilliard Subject: RE: COZY: F-22 Doubler Lay-up Date: Fri, 11 Sep 1998 21:46:33 -0500 Jody, I overlapped top & bottom only. In fact, the top will get chopped off later so that's not even important. Greg Hilliard cozy mk4 #456 gjhilliard@idcnet.com ---------- From: Joseph H. Hart IV[SMTP:jodyhart@communique.net] Sent: Friday, September 11, 1998 5:01 PM To: cozy_builders@canard.com Subject: COZY: F-22 Doubler Lay-up When doing the lay-up on the F-22 Doubler, it appears from the diagrams that the only place the "previously glassed area" is overlapped is at the bottom, below the sloped edge of the doubler. However, if read literally, the text states to overlap on all sides of the doubler. Which interpretation is correct? If I overlap on all sides, does that include the top edge, which is even with the top edge of F-22? Also, if I overlap on all sides, shouldn't I round over all edges of the doubler? I feel pretty confident that I am only supposed to overlap at the bottom but I've been wrong before! I would like to glass F-22 tonight, as we have severe flooding here in New Orleans and there is nothing else to do. Any advice, as always, is appreciated. Jody Hart Date: Tue, 15 Sep 1998 22:49:01 -0500 From: "Joseph H. Hart IV" Subject: COZY: Is the bottom of the Instrument Panel flat? Is the botton of the Instrument Panel supposed to be flat? When I match up the templates on the lines, the center of the bottom is lower than the sides. Are my templates distorted? Am I simply lining them up wrong? I've cut out the actual templates rather than tracing which rules out an error in tracing them. Thanks, Jody Hart jodyhart@cmq.net Date: Tue, 15 Sep 1998 23:49:04 -0500 From: "Joseph H. Hart IV" Subject: Re: COZY: Is the bottom of the Instrument Panel flat? Ok, I don't know what I was thinking (someone was talking to me while I was writing) in that last one, I did photocopy the top and bottom to use as one side and cut out the original for the other side. I held them up to a picture window and they aligned perfectly to the unaided eye. To make things worse, I just measured the bulkhead templates (originals) and the measurements listed on them are almost all off -- this despite the fact that one measurement is listed to two decimal places, which implies that it is accurate to one one-hundredth of an inch (which I know is beyond the possible accuracy with this type of line drawing). Many of the measurements are off by more than two tenths of an inch. Is this ok? Should I use the lines on the templates or the measurements off of the templates? Thanks again, Jody Hart jodyhart@cmq.net From: Cozy7971@aol.com Date: Wed, 16 Sep 1998 09:14:24 EDT Subject: Re: COZY: Is the bottom of the Instrument Panel flat? In a message dated 98-09-16 00:04:24 EDT, jodyhart@communique.net writes: << Are my templates distorted? Am I simply lining them up wrong? I've cut out the actual templates rather than tracing which rules out an error in tracing them. >> Jody, I would suggest that you consider tracing in the future. I found that the templates are not always exact when taped along the match line. This is apparent in the various bulkheads. In some places it is obvious that the piece must be symetrical about the centerline. If you take a few measurements you will see inaccuracies. I believe that printing problems and distorion on the paper may be the culprit. There was actually a discussion about this on the Cozy list several years back. Take a look at the archives. I basically re-did the drawings to cause all lines perpendicular to the centerline to be perpendicular. I then took measurements off the centerline for various points and played connect the dots. For curves and the like I used the original drawings and traced the lines. Take care to do things accurately. It will save you a lot of grief later when you try to assemble. Dick Finn Date: Wed, 16 Sep 1998 08:17:43 -0500 From: Tom Brusehaver Subject: Re: COZY: Is the bottom of the Instrument Panel flat? >Is the botton of the Instrument Panel supposed to be flat? When I match >up the templates on the lines, the center of the bottom is lower than >the sides. Are my templates distorted? probably. Mine was this way. I figure it is my airplane, I'll make the panel how I want. I'll try it the way the plans came out, and if it isn't right, I'll change it. >things worse, I just measured the bulkhead templates (originals) and the >measurements listed on them are almost all off -- this despite the fact that >one measurement is listed to two decimal places, which implies that it is >accurate to one one-hundredth of an inch I remember one night last winter my wife and a couple others were working in our basement, and not wanting to disturb them I took one of the landing gear bulkhead drawings and some foam upstairs. I remember there were measurements all over it, and I thought, no need to trace, I'll just measure everything, and draw it on there. It turned out, most of the measurements were there. I still had to trace something, and I was shocked how far things were off. I remeasured as much as I thought necessary, but was sure the drawings were distorted. (not jabbing at Nat, I understand his position), having the CAD files available would allow people with plotters available would overcome some of these questions. Date: Wed, 16 Sep 1998 08:38:03 -0700 From: michael amick Subject: Re: COZY: Is the bottom of the Instrument Panel flat? Joseph H. Hart IV wrote: > Should I use the lines on the templates or the measurements off of the templates? Jody I found the same problem and made the panel flat (or straight) on the bottom edge using the outside height measure. Well, when I mated the Instrument Panel to the fusalage sides it was approximately 1/4" short. I modified the fuselage bottom to make up the difference but I recomend that you increase the length of the sides of the Instrument Panel to match the center height. As a double check see chapter 5 page 3 Fig 5. The measures of the fusalages sides top to bottom at Fuselage Station 42" should measure 20.9" The FS of the IP is F22+19.25" i.e. 41.25" Compare 20.9" with the IP template and adjust accordingly. Regards Michael Amick Chapter7 From: lschuler@cellular.uscc.com Date: Wed, 16 Sep 98 09:13:54 -0600 Subject: Re: COZY: Is the bottom of the Instrument Panel flat? Jody Hart wrote: >Is the botton of the Instrument Panel supposed to be flat? When I >match up the templates on the lines, the center of the bottom is lower >than the sides. Are my templates distorted? Am I simply lining them >up wrong? Great question! I say this 'cause I have the same problem with most of the drawings (not just the instrument panel). The further off the center of the page, it appears that the errors increase. FWW: I made mine flat. Seemed to make sense with seatback bottom flat and F22 flat as well. Having a curve on the bottom may help in stability just a tiny bit, and may help shape the nose a tiny bit; but, the aggravation when you get to the belly board and it's hinge would not be an even trade. Check your firewall templates and you will find some water line ticks along the side. The numbers indicate the ticks are 1" apart. Measure them and try to keep from fainting. The reason the drawings are not very good is due to the manner in which they were made as well as the manner in which they are reproduced. Marc is not alone in his frustration on tolerances etc. Makes ya wonder how these things fly, but they do. Hang in there. Larry Schuler MK-IV #500 Ch-13 in a holding pattern while I relearn welding skills I haven't used for a while. From: "L. Wayne Hicks" Subject: RE: COZY: Is the bottom of the Instrument Panel flat? Date: Wed, 16 Sep 1998 11:33:54 -0400 -----Original Message----- From: michael amick [SMTP:mkamick@wans.net] Sent: Wednesday, September 16, 1998 11:38 AM To: Joseph H. Hart IV Cc: cozy_builders@canard.com Subject: Re: COZY: Is the bottom of the Instrument Panel flat? Jody when I mated the Instrument Panel to the fusalage sides it was approximately 1/4" short. [L. Wayne Hicks] I had the same problem. Prior to floxxing on the bottom to the fuselage in Chapter 6, I cut out a thin spacer strip from 0.2-inch Clark foam, micro'd it onto the bottom on the IP, then sanded until it was flat and flush with the lower longerons. Wayne Hicks Cozy IV #678 Chapter 7 Date: Wed, 16 Sep 1998 15:58:48 -0500 From: Bulent Aliev Subject: Re: COZY: Is the bottom of the Instrument Panel flat? Hi all, I found out that most of the full size drawings in the plans are distorted. Fortunately noticed it at the beginning and later even two part airfoil drawings did not match with each other. It's up to you to be critical of them and adjust to fit. Too bad we have to work from cheap photo copies included in the plans instead of proper, distortion free prints like I have seen come with the RV, Lancair and other planes. Bulent From: Militch@aol.com Date: Wed, 16 Sep 1998 16:32:20 EDT Subject: COZY: Inaccurate copies of key drawings I notice that the archives contain some letters from folks who went to the trouble of entering some of their parts into autocad or other drawing systems specifically to get around this problem. The files are probably still available, so if the parts are still dimensioned today as they were a couple of years ago, a builder could get them plotted full size and avoid some of the "eyeball" adjustments and corrections that appear to be necessary. Actually, to be fair, $500 for a full set of plans for anything is pretty reasonable. If the plans packages were full size plotter runs, I'll bet the raw reproduction cost would add quite a bit to the price. Peter Militch (planning to buy some plans real soon now). From: "L. Wayne Hicks" Subject: RE: COZY: Is the bottom of the Instrument Panel flat? Date: Wed, 16 Sep 1998 17:01:27 -0400 -----Original Message----- From: Bulent Aliev [SMTP:atlasyts@idt.net] Sent: Wednesday, September 16, 1998 4:59 PM To: Joseph H. Hart IV Cc: cozy_builders@canard.com Subject: Re: COZY: Is the bottom of the Instrument Panel flat? Too bad we have to work from cheap photo copies included in the plans instead of proper, distortion free prints like I have seen come with the RV, Lancair and other planes. Bulent [L. Wayne Hicks] What you say may be true, but I wish you could hear the complaining the two local Lancair builders in our area do. They constantly complain about instructions that don't make sense, lack of support from the factory, inferior parts, holding back safety information, etc. One of the primary reasons I chose to build the Cozy was the outstanding support from the designer and my fellow builders. The Lancair guys don't have nearly the web and archive stuff we have, although Marv Kaye (sp?) is making a run at it. Oh yeah, we complain about little things, but those guys complain about BIG things. From: "Kurt A. Schumacher" Subject: RE: COZY: Inaccurate copies of key drawings Date: Thu, 17 Sep 1998 00:50:21 +0200 Finally my plan set showed up here in Switzerland, thank you Nat. First thing I have done today was the creation of working copies, cut the parts - and tried to fit :-{ . Next step will be to take them to the drawing board and make the corrections needed. The only point I really miss is some "control information", e.g. bulkhead width and height. Having the match lines alone is not enough. Probably I CAD' them again... Don't think this is really needed, obviously there are some hundred people having built their bulkheads and fuselages with success. For me (6'4"/220lb) the main reason to take this effort is to figure out the minor changes needed. Conclusion: Drawing/reproduction quality might be enough to BUILD - if you want to do some ENGINEERING work (what is requested for me in Switzerland by the BAZL [Swiss FAA] anyway!) or some kind of minor alterations, a higher quality might be preferred. Everything metioned here is legal according to US and Swiss law, as long as I use this information (data or whatever) to build ONE single plane for my personal usage. On the other hand I fully understand Nat to knock on his copyright and his quality control. He had and probaly still has some bad experience on this point: > From: Nat Puffer > To: Kurt A. Schumacher > Received: Thu, 10 Sep 1998 14:56:26 -0700 (MST) > Kurt, > Sorry, but we do not wish to release the same drawings we have in our plans > over the internet, because they are copyrighted, and we would have no > control over who copies them. > Regards, > Nat Looks as I am not the only one... Hope Nat and the Cozy builders community can find a solution fit to both interests and needs. Kurt Mk.IV #717, Subject: Re: COZY: Is the bottom of the Instrument Panel flat? Date: Wed, 16 Sep 1998 16:07:51 -0500 Cozy builders, For the record, the large sized drawings were printed on a printing press. Nat ---------- > From: Bulent Aliev > To: Joseph H. Hart IV > Cc: cozy_builders@canard.com > Subject: Re: COZY: Is the bottom of the Instrument Panel flat? > Date: Wednesday, September 16, 1998 3:58 PM > > Hi all, > I found out that most of the full size drawings in the plans are > distorted. Fortunately noticed it at the beginning and later even two > part airfoil drawings did not match with each other. It's up to you to > be critical of them and adjust to fit. > Too bad we have to work from cheap photo copies included in the plans > instead of proper, distortion free prints like I have seen come with the > RV, Lancair and other planes. > Bulent > > From: John Ellor Subject: RE: COZY: Is the bottom of the Instrument Panel flat? Date: Wed, 16 Sep 1998 10:04:46 -0400 Hi Jody, Re "....Is the bottom of the Instrument Panel supposed to be flat?......" Had the same "problem" on my Cozy III, - worried over it just like you. Don't worry 'bout it. Assuming your IV is like my III, the bottom of the panel bulkhead must be flat to match up to the fuselage bottom. The fuselage bottom sheet curves fore/aft, and I don't recollect any curvature anywhere transversely, - until you start carving the exterior. The apparent curvature on the panel bulkhead bottom wasn't that much anyhow, - it may well be "lost in the flox" when you attach the bottom. You can always adjust (flatten) it anyhow if need be when you have the sides and bulkheads assembled. I think a lot of us are trying to make everything from plans much more precisely than was intended, I know I'm guilty and it has slowed me down. Things are pretty well called out where accuracy is critical though. Regards, John Ellor Cozy III #283, - Still plodding on. Date: Thu, 17 Sep 1998 11:11:47 +0200 From: Rego Burger Subject: COZY: Drawing accuracy I never noticed any discrepancies with my drawings (Cozy Mk IV plans) but then my method may overlook any, if any existed. I always used a centerline and only half the drawing, I would flip the drawing over and mirror-image it. This way I got a symetrical former / bulkhead... I never had any problems fitting them. There is always a danger if you paste any drawing onto cardboard of getting skrinkage from the glues used? If you must glue a drawing, use epoxy, it shrinks the least. This goes for glueing the airfoils to templates too. If you need to copy drawings to keep originals clean and neat...test the copier. Place a flat ruler with high contrast markings on copier.... compare measurements after copying.... I've had to set a machine to 1% up or down to match on the odd occasion with other drawings. This is a sign that the copier is not perfect. When I get home I'll compare my left side to the right side of the panel just for fun. Happy Building. Rego Burger Web site: http://home.intekom.com/glen/rnb.htm e-mail home- mailto:rnb@intekom.co.za RSA...... Date: Thu, 17 Sep 1998 07:10:23 -0400 From: bil kleb Subject: Re: COZY: Drawing accuracy Rego Burger wrote: > > I never noticed any discrepancies with my drawings (Cozy Mk IV plans) > but then my method may overlook any, if any existed. were the second edition plans made differently from the first? it seems that at least three second edition plan holders (>500?) have mentioned the 1/4" discrepency on the instrument panel, whereas this has not been mentioned by first edition plans holders... -- bil From: cdenk@ix.netcom.com Date: Thu, 17 Sep 1998 07:11:27 -0500 (CDT) Subject: Re: COZY: Drawing accuracy Some copiers fine adjustment is only in the direction of travel. Check both ways. Paper will easily move +/- 1% due to humidity. Linen cloth is a little better, but mylar is best. Date: Thu, 17 Sep 1998 05:41:34 -0700 (PDT) From: Mark Loy Subject: COZY: Plan reproduction stuff Hi to all, I've been a civil draftsman and designer for about 13 years before I took a position in another field. I've made millions of reproductions on MANY machines. In my honest opinion, the plans that Nat sells are not that bad when it comes to matching match lines and such. I tried to copy the bulkheads on our brand new $250,000.00 reproduction machine, and the reproductions I got were off by quite a lot. (Oce' are you listening?) I think that it would be a nice addition to the plans, if Nat would offer the bulkhead outlines and foam cutting outlines on a floppy disk, in .dwg or .dxf format, for us CADD users. These could be offered for a nominal cost and he would have control of who gets what. I know that this has probably been thought of before, so I appologize if it has been beaten to death already..... Thanks, Mark Loy Waitin' on Wicks for Chapter 5 stuff..... _________________________________________________________ DO YOU YAHOO!? Get your free @yahoo.com address at http://mail.yahoo.com From: lschuler@cellular.uscc.com Date: Thu, 17 Sep 98 08:07:41 -0600 Subject: Re[2]: COZY: Is the bottom of the Instrument Panel flat? Nat Puffer wrote: >Cozy builders, >For the record, the large sized drawings were printed on a printing press. Does that mean the originals are distorted? Not trying to pick on you as I may have in the past Nat; but, this is an old and well known problem with your drawings [check the archives]. Three good examples for you to easily check on your originals: 1. Measure the water line ticks on your firewall drawing. If they are exactly an inch, then the original is probably OK. 2. Check horizontal match lines and bulkhead bottoms for squareness with the center line. If they are, then the originals are probably OK. 3. Overlay canard templates A and B. If they match perfectly, then the originals are probably OK. Obviously, if these three checks show any error on the originals, it would be wise to check 'everything' and fix as necessary. If the originals check out, then you might want to consider alternative printing/copy process. I think we'd all like to know how these checks turn out. Larry Schuler MK-IV plans #500 From: N11TE@aol.com Date: Thu, 17 Sep 1998 12:05:01 EDT Subject: Re: Re[2]: COZY: Is the bottom of the Instrument Panel flat? In a message dated 9/17/98 9:11:19 AM EST, lschuler@cellular.uscc.com writes: << >Cozy builders, >For the record, the large sized drawings were printed on a printing press. Does that mean the originals are distorted? >> In defense of Nat, I worked for a printing company for over 15 years. I can tell you that all printing plants are both closely temperature and humidity controlled. Normally, new skids of paper are not opened after receipt for several days to allow the paper to "condition." Changes in temperature and humidity can make significant differences in the sizing of paper... I've seen a sheet stretch over 1/4 inch. So, if your plans are kept in a high humidity basement, the drawings can be significantly different in size from plans kept in Arizona. This is simply a problem with the system and is directly proportional to the quality of the paper used and the weather conditions. To use a more stable material could very well push the cost of the plans out of the economic range. After all, you are getting a whole lot for only $500.00! In short, you should check dimensions on each drawing before use to see if the atmospheric conditions have pushed the sizing of the drawings out of your range for tolerance. And then adjust as necessary. Tom Ellis Cozy MKIV plans #25 From: Cozy7971@aol.com Date: Thu, 17 Sep 1998 12:48:19 EDT Subject: Re: COZY: Is the bottom of the Instrument Panel flat? << Too bad we have to work from cheap photo copies included in the plans instead of proper, distortion free prints like I have seen come with the RV, Lancair and other planes. Bulent >> I hope people are not drawing the wrong conclusion about the quality of the plans. The two books are super. It's hard to imagine how someone could include so much detail. The drawings are also great. There are inaccuracies due to the printing process (I assume) but I considered these to be minor. As noted in an earlier e-mail, the problems become obvious and I easily resolved them by redoing specific drawings. The problem only seems to become an issue with the large drawings that span multiple sheets of paper. I did not note any issues with the hot-wire templates. Dick Finn Cozy Mark IV #46 From: lschuler@cellular.uscc.com Date: Thu, 17 Sep 98 14:24:45 -0600 Subject: Re: Fwd: COZY: Drawing accuracy Bil Kleb wrote: >> were the second edition plans made differently from the first? it seems >>that at least three second edition plan holders (>500?) have mentioned >>the 1/4" discrepency on the instrument panel, whereas this has not been >>mentioned by first edition plans holders... John Fritz wrote: >I have MK IV plans before 500 and I also noticed that the bottom of >the instrument panel was not perpendiculat to the center line. I recall >it was off by somewhere between .25 to .125 inch. Mine is off too. As a matter of fact, all large drawings which should have had verifiable perpendicular lines do no have perpendicular lines. There are a number of other curve-matching issues as well, such as canard templates. All pages repeatedly check square as well as left-right and top-bottom measurement comparisons on each page check OK. Both within acceptably small limits for paper quality vs humidity changes. Either the ink is crooked on my copies; or, the originals are, and were faithfully copied as such. With my limited knowledge of both processes, I cannot tell which may be true, or if both are contributors. Larry Schuler Plans #500 From: lschuler@cellular.uscc.com Date: Thu, 17 Sep 98 13:58:28 -0600 Subject: Re[4]: COZY: Is the bottom of the Instrument Panel flat? Tom Ellis wrote: >In defense of Nat, >... >In short, you should check dimensions on each drawing before use to see if >the atmospheric conditions have pushed the sizing of the drawings out of your >range for tolerance. And then adjust as necessary. Can't disagree with the idea here, nor the idea we get what we pay for. Problems with what you suggest are that Nat doesn't publish dimensions on all drawings which would allow the post-purchase cross-check; and, I believe, cannot provide airfoil template coordinates/dimensions because he doesn't actually have them [even if he were inclined to do so due to copyright issues]. As for paper stretch/shrink, I think most of us that have discussed this before (see archives), understand that issue. It is also known that one sheet of paper doesn't change on one end relative to the other that much. It may change overall from it's original form, but that change is generally fairly even (based on paper quality) across the page. If the page is cut square by machine (which is normally the case), this can be easily checked with a square. If the paper is still square in the shop, then it's fair to expect square ink. Warpage across the page can easily be tested by measuring and comparing the edge lengths of the paper left-right and top-bottom. If these check out then it is also fair to expect straight, non-warped ink if the printing process is any good. The difference most of us have seen between canard template 'A' and canard template 'B' is way outside the affects of the shrink/stretch tolerance of the paper. Also, the water line tick measurements on the firewall are way outside normal paper shrink/stretch expectations. It's easy to see that most, if not all, of the drawings were done by hand and not via CAD. Not slamming Nat for that by any means; that's the way it is. Shoot, it wasn't till a few years ago that the RV drawings were converted to CAD. Some folks may also still use slide rules (which are, for the most part, what helped create the atom bomb). Just means the prints we have are basically copies, not original prints (which could easily and cheaply be done via calibrated CAD plotter). May be asking way too much for these to be converted and validated with another proof plane. Very labor intensive (as CAD-literates will verify). Cost, as suggested, is an obvious issue. May be an additional case of modified copies of modified copies of someone else's copies. I suspect is true, since I believe, Nat modified his Long EZ drawing 'copies' which he started with to a Cozy and modified a 'copy' of the Cozy drawings to a MK-IV; and, the originals of the source are in Burt's vault. Nat may be willing to share the real story here (if it isn't too embarrassing). The information won't fix the problem, but would certainly help in the understanding department. Larry Schuler Date: Thu, 17 Sep 1998 21:12:56 -0500 From: Bulent Aliev Subject: Re: Fwd: COZY: Drawing accuracy As much as I did not get involved again in the issue I must say: For 20 years I was involved in the commercial photography, production and printing field. If you have a good original, it may get distorted later in the pre-printing process. If the printing plates and film are not made using the contact method, but using photo camera, there will be distortion most pronounced in the edges of the image. The contact method is 100% accurate, but expensive. If you photograph a sheet of grid paper with a camera no matter how good the camera, the print image will be less then perfect grid. And I do not agree with the "You get what you paid for" thinking. More than 1000 sets of plans times $500 .......=..... I have no problem with Nat making good profit, just that the quality of the plans should improve in parallel with number of plans sold. Just my 2 cents. Bulent Date: Thu, 17 Sep 1998 23:21:45 -0400 From: George Berven Subject: Re: COZY: CH. 4 Reproducing drawings Just wanted to interject the method I used for reproducing the drawings. Tracing is a pain, photo-copying in expensive and increases inaccuracies, CAD is not always accessible, so, here's what I did. Tracing with a twist. 1) Take a large sheet of paper and fold it in half to form a vertical centerline. 2) Match the centerline of the bulkhead to be copied on "top" of the paper centerline (still folded). Tape on 4 corners only with masking tape. 3) Make (2) large sheets of carbon paper by taping (4 or 6) pieces together (small bits of scotch tape). 4) Slide one sheet of carbon paper under the plans, and the other face up on the table (under the whole thing) to form the mirror image. 5) Use a ball point pen and straight edge and just draw over the original plans. Use a color other than black so you know where you've drawn. This method lets you make a perfect reproduction by only "tracing" the bulkhead once. No straining your eyes to see through the paper either. By default the centerline defines its' perpendicular on the copy as parallel to the papers' edge which may not be true on the original. It's better than photocopying because I learned alot. Originals are not cut up and are retained for future reference. PLEASE COMMENT ON THE IDEA BELOW... What I'd like to do now is make my bulkheads as a large rectangular sheet; put on the appropriate number and orientation of plys, add "peel-ply", and on top of that add the paper copy of the bulkhead so that it is epoxied to the peel-ply. After completely dry I could then use a bandsaw (Marc Z.'s recommendation) to cut out the finished product. Epoxy shrinkage? Bandsaw blade type and speed? Unforeseen problems? Thank you for this forum. George Berven gberven@erols.com Cozy IV #615 Chapter 4 Rego Burger wrote: > I never noticed any discrepancies with my drawings (Cozy Mk IV plans) > but then my method may overlook any, if any existed. > I always used a centerline and only half the drawing, I would flip the > drawing over and mirror-image it. > This way I got a symetrical former / bulkhead... I never had any > problems fitting them. There is always a danger if you paste any drawing > onto cardboard of getting skrinkage from the glues used? If you must > glue a drawing, use epoxy, it shrinks the least. This goes for glueing > the airfoils to templates too. > Date: Fri, 18 Sep 1998 00:20:46 -0500 From: "Joseph H. Hart IV" Subject: COZY: Q of the day: BID overlap strength? I've cut the glass for the IP and LG bulkheads and, despite having ordered 5 yds each of UNI & BID extra, run out of BID for the firewall. I have plenty of decent sized scraps. Am I sacrificing strength (or anything else for that matter) by using scraps to make the firewall layups? I would be using a maximum of 3 pieces per side per upper firewall and the same for the lower firewall. Is this ill-advised or will the standard 1 inch overlap provide strength approx. equal to a full size, uncut piece. Also, I recall from the past week or so that someone stated that one doesn't have to cut of the selvedge from the new BID from Wick's. Has anyone else seen this glass? Is there general agreement that the selvedge does not have to be removed? Thank you, Jody Hart jodyhart@cmq.net From: "L. Wayne Hicks" Subject: RE: COZY: CH. 4 Reproducing drawings Date: Fri, 18 Sep 1998 08:27:43 -0400 -----Original Message----- From: George Berven [SMTP:gberven@erols.com] Sent: Thursday, September 17, 1998 11:22 PM To: cozy_builders@canard.com Subject: Re: COZY: CH. 4 Reproducing drawings PLEASE COMMENT ON THE IDEA BELOW... What I'd like to do now is make my bulkheads..... (and) use a bandsaw (Marc Z.'s recommendation) to cut out the finished product. George Berven [L. Wayne Hicks] Your tracing method will certainly work. Glassing first then cutting later will work, too, but you might want to check something first. In Chapter 3 (I think), there is a handy chart that shows how to lay out parts to make maximum use of minimum materials. If you do this, is possible that some of the pieces may not end up with the proper fiber orientation. So plan ahead to ensure all fiber directions are as per plans and that you have enough material on hand. Wayne Hicks Cozy IV #678 Chapter 7 From: "norm doty" Subject: Re: Fwd: COZY: Drawing accuracy Date: Fri, 18 Sep 1998 10:50:06 -0400 boy if that aint the truth, i dont understand what all the bitc---g is about, ive not had these problems, and the only ones i have had for the most part 98% were of my own making and only 2% were the plans, if these problems are so bad then why dont you suggest the changes to nat so plans set #3 can incorporate them! lets be constructive here and help others instead of trying to lop off heads. this thread started good but then got into back stabing and bitc---g. norm & monda cozy IV #202 finally seeing the light at the end of the tunnel (i hope its not an oncomming train) -----Original Message----- From: Jim Hocut To: 'Bulent Aliev' ; lschuler@cellular.uscc.com Cc: cozy_builders@canard.com ; Fritzx2@aol.com Date: Thursday, September 17, 1998 11:31 PM Subject: RE: Fwd: COZY: Drawing accuracy >On Thursday, September 17, 1998 10:13 PM, Bulent Aliev >[SMTP:atlasyts@idt.net] wrote: >> And I do not agree with the "You get what you paid for" thinking. >> More >> than 1000 sets of plans times $500 .......=..... >> I have no problem with Nat making good profit, just that the >quality >> of >> the plans should improve in parallel with number of plans sold. >> Just my 2 cents. > >1000 sets of plans times ($500 - printing costs - advertising costs - >legal fees - expenses - ....) / 10(?) years. Yeah, it's pretty >obvious somebody's making a small fortune here. (How to make a small >fortune in aviation - start with a large one). > > >Jim Hocut >jhocut@mindspring.com > > > From: lschuler@cellular.uscc.com Date: Fri, 18 Sep 98 09:11:21 -0600 Subject: Re[2]: COZY: CH. 4 Reproducing drawings George Berven wrote: >Tracing with a twist. I basically did same. Make darn sure the fold is dead-on straight and pressed very well. Works like a charm. Except I didn't use an off-color pen. Should have. next time.... >What I'd like to do now is make my bulkheads as a large rectangular >sheet; put on the appropriate number and orientation of plys, add >"peel-ply", and on top of that add the paper copy of the bulkhead so >that it is epoxied to the peel-ply. After completely dry I could then >use a bandsaw (Marc Z.'s recommendation) to cut out the finished >product. What you suggest could work. I do basically the same, but rather than epoxying the drawing to the peel ply, I wait for cure, then use short strips of double sidded tape to hold the drawing to the piece while cutting. Just make sure that some of the strips stradle the cut line(s). Don't use entire sheet if it isn't necessary. About 1/2" or so outside the drawing size is usually sufficient. Edges can be a bit off in resin content and micro due to the squeege pressure locally, so this extension helps eliminate this issue. Keep the cut off pieces of foam for other uses; they come in handy later. Band saw I use is made for wood (= cheap 14" Menards import version); however, I use a fine-tooth metal cutting blade. I wouldn't use a coarse blade; it would delaminate the underside too much without backup material. I always cut outside the drawing lines just a bit (about 1/16" to 1/8", or so) because of the fine edge delam that does occur; then use sanding block to do final shape. This also helps to remove slight wavyness from the cutting. Larry Schuler MK-IV plans #500 From: aircraft Subject: RE: COZY: RE: Drawing Accuracy Date: Fri, 18 Sep 1998 14:53:40 -0400 All, There might be some problems. But the overall quality of the plans and drawings are outstanding. I had some of the same concerns/problems in the beginning but have figured out how to reference the drawings to the text. The plans and drawings are of about the same quality as the Tech Manuals the I use to maintain the Army's Apache Attack Helicopter (with fewer mistakes). Thanks Nat for a Great set of Plans. And lets give this issue a rest!!!. Dave TELFORD/ACCI Dave West (502) 624-2746 DSN 464-2746 Fort Knox, KY 40121-5000 FAX (502) 942-3525 EMail Address: Aircraft@ftknoxdol-emh10.army.mil > ---------- > From: Don Bowen[SMTP:DonBow@symix.com] > Sent: Friday, September 18, 1998 12:34 PM > To: 'cozy_builders@canard.com' > Subject: COZY: RE: Drawing Accuracy > > Just my 2 cents worth on the accuracy of the Cozy drawing / plans > package: > > Having spent 14 years in the aircraft maintenance and modification > business I can attest to the fact that engineering documentation is > always subject to criticism by users. I have worked with drawings from > professional engineers (Boeing, McDonnel Douglas, Lockheed, Learjet, > Grumman, etc.). Some are better than others, but there is always some > detail you can find to nit-pick about. > > When getting ready to install the bottom of the fuselage, I found that > the instrument panel of my Cozy Mk IV was .2" short. No big deal, I > filled the gap with a small strip of foam and went on with completing > the fuselage. Overall, I was amazed at how well the individual parts > went together to complete the fuselage assembly. The plans are good > enough to build successfully build an airplane. Hundreds of flying > canard planes prove this point. To his credit, Nat has always been > there to answer any questions I came up with (not many). > > I agree that the plans could improved with the use of CAD, but I > certainly would not want to pay the increased costs. Trust me on this, > professional type engineering drawings and documents are pretty > expensive. When you purchase engineering from any of the major aircraft > companies you pay a lot more than the $500 we pay. > > Since RAF stopped selling plans, we are very fortunate that Cozy > Development has the license to sell us the "Rutan" based plans. I think > this group has spent too much time bashing Nat and not enough time > working on their airplanes. We are definitely getting our money's worth > with the purchase of Cozy plans. > > One tip on tracing from the templates. I scotch taped the original > drawings and a similar sized piece of white paper to a sliding glass > door. In the daylight, you can see right through the paper and can > easily trace the template onto the white paper. > > Don't worry, be happy! > > Don Bowen > Cozy Mk IV s/n 440 > > From: cdenk@ix.netcom.com Date: Mon, 21 Sep 1998 07:27:21 -0500 (CDT) Subject: Re: COZY: LG Local Layup Error! Is mechanical bond good enough? On 09/21/98 01:46:56 you wrote: > >Got complacent (already!) and failed to do the local layups of 8 UND on >the forward face of the aft LG bulkhead and 3 UND on the aft face. I >peel-plied the overall layups. Is the mechanical bond of local layups >over the cured but peel-plied overall layups of sufficient strength to >continue or do I need to start over again? If it is strong enough, how >much, if any, strength am I losing? > >Thanks. > >Jody Hart >jodyhart@cmq.net >Cozy Mk IV, #648 >N359JH > > > The instructions clearly indicate after removing the peal ply, it is OK to continue laying up. Invest in a Yellow Hilighter (transparent yellow felt tip pen), after completing a step, hilight that portion. Many times that will be less than a paragraph or sentence. Then you will be able to see what is remaining. Date: Mon, 21 Sep 1998 09:11:01 -0400 From: David Domeier Subject: Re: COZY: LG Local Layup Error! Is mechanical bond good enough? Jody, re "I peel-plied the overall layups. Is the mechanical bond of local layups over the cured but peel-plied overall layups of sufficient strength to continue or ...?" Yes. In fact the winglet is attached to the wing over a peel-plied surface since day one in this process. dd From: lschuler@cellular.uscc.com Date: Sat, 19 Sep 98 12:27:58 -0600 Subject: COZY: Drawings and stuff I've seen a wide variety of comments about the plans drawing accuracy issue; including my own $0.00 worth. Just an observation, but seems to me that the variety of comments are about as diverse as workmanship witnessed in the show plane area at Oshkosh. We have a wide variety of skills, technical competence, experiences, knowledge, opinions, and so on here on this list; each at both ends of the spectrum, I'm sure. From those who are adept and demanding at 0.0005" tolerances and those who are more comfortable with 0.1", or thereabouts flox-fill. Some folks use tape measures and carpenter levels to hang pictures, some have a hard time putting a bulldog picture hook on the wall without driving the hammer through the gypsum. I do not envy our esteemed designer's task of trying to be all to all while trying to also meet his own desires and needs. There's a heck of a diverse group out here. It must feel like tap dancing on hot coals some times I'm sure. I have no problem with him making money from what he has done and continues to do. We could do the same, but it's our choice not to. We cannot understand until we have walked in his moccasins. (Wait a second while I wipe the brown off my nose...:-)). Now, having said that and understanding that the designer has a reputation and livelihood at stake while we have our lives and the lives of our passengers at stake, I think it is also fair and reasonable to expect continuing improvements in the plans, drawings, instructions or whatever as long as the marketing/sales side of our supplier (the designer) is advertising customer support, is informed of, or discovers errors on his own, and has in place a means to distribute information to the purchasers. If we look at all the back issues of the newsletters, including Cozy-III letters, we will see that corrections and refinements have been done with a real zest in the past. More recent newsletters seem to be getting thinner and thinner in this respect. It would be reasonable to gather form this, that the plans are reaching perfection and require fewer and fewer adjustments. We each must draw our own conclusions. Mine bothers me. Larry Schuler MK-IV plans #500 From: "Steve Campbell" Subject: COZY: Chapter 4 Date: Wed, 14 Oct 1998 09:08:32 >Dear cozy group, > > During knife trim of the instr. panel bulkhead I accidently bent >the panel up a few inches and caused a crack in the foam core board (.2" >thick). The layup on the one side still looks great - no indication of >the crack. Would carving a small V at the crack and stiff microing it >before laying up the other side be sufficient? Thanx for your input. >_______________________ >Dana Hill The question is whether or not you have damaged the fibers. The panel is a structural member in this plane and so strength is important (Not withstanding that you will later drill it full of holes.) The crack in the foam is quite incidental and the micro solution that you suggest would work well. Steve Campbell Cozy #367, now more of an Aerocanard Steve Campbell Professor, ECE University of Minnesota 200 Union Street Minneapolis 55455 Campbell@ece.umn.edu (612) 625-5876 (612) 625-4583 (fax) From: Epplin John A Subject: RE: COZY: Ch 4, Instr. Panel Layup Date: Wed, 14 Oct 1998 09:07:22 -0500 If I remember correctly, the panel is made up from pieces of .2 in. foam glued together already. Why not flex the crack open enough to get if filled with micro slurry when you laminate the other side? This should be no different than bonding pieces together. Maybe better, the parts should fit near perfectly. John Epplin, Mk4 #467 > -----Original Message----- > From: dhill36@juno.com [SMTP:dhill36@juno.com] > Sent: Wednesday, October 14, 1998 8:40 AM > To: cozy_builders@canard.com > Subject: COZY: Ch 4, Instr. Panel Layup > > Dear cozy group, > > During knife trim of the instr. panel bulkhead I accidently bent > the panel up a few inches and caused a crack in the foam core board (.2" > thick). The layup on the one side still looks great - no indication of > the crack. Would carving a small V at the crack and stiff microing it > before laying up the other side be sufficient? Thanx for your input. > _______________________ > Dana Hill > CZ IV, #676 > Ch 4 > > ___________________________________________________________________ > You don't need to buy Internet access to use free Internet e-mail. > Get completely free e-mail from Juno at http://www.juno.com > or call Juno at (800) 654-JUNO [654-5866] From: Fritzx2@aol.com Date: Wed, 14 Oct 1998 16:07:39 EDT Subject: Re: COZY: Ch 4, Instr. Panel Layup Dana Hill wrote: > During knife trim of the instr. panel bulkhead I accidently bent > the panel up a few inches and caused a crack in the foam core board (.2" > thick). The layup on the one side still looks great - no indication of > the crack. Would carving a small V at the crack and stiff microing it > before laying up the other side be sufficient? Thanx for your input. As long as your sure the glass did not delaminate from the foam or the glass was not damaged, either 5 min. epoxy or a "V" grove filled with micro should be adequate. John Fritz fritzx2@aol.com From: RWhitt1245@aol.com Date: Wed, 4 Nov 1998 20:43:11 EST Subject: COZY: FS22 I think Ive been "Spruced" again by a major suppler. What type of material does the Cozy use for the FS22 bulkhead? Is it foam or plywood? If it is foam , what is the weight and type? Thanks Ron e-racer #346 Date: Thu, 05 Nov 1998 08:43:42 -0500 From: David Domeier Subject: Re: COZY: FS22 Ron, re " What type of material does the Cozy use for the FS22 bulkhead? Is it foam or plywood?" I used Clark 18 lb., .2", while high density stuff. Airplane is flying and hasn't come apart yet. dd From: cdenk@ix.netcom.com Date: Tue, 22 Dec 1998 21:39:34 -0600 (CST) Subject: Re: COZY: seat cutouts On 12/22/98 19:40:23 you wrote: > >THis is kind of a right angle turn but did you all seal the bare foam in >the map pocket cutout and fuel valve cutout with a ply of bid or what? >Jeb > > I left mine bare, and after 5 years, it hasn't been noticed, and its lighter weight. Date: Tue, 29 Dec 1998 13:04:34 -0500 From: bil kleb Subject: Re: COZY: seat cutouts cozy623@juno.com wrote: > > THis is kind of a right angle turn but did you all seal the bare foam in > the map pocket cutout and fuel valve cutout with a ply of bid or what? from the cozy faq at: http://cozy.canard.com/mail_list/cozy-faq.html 4.19 - How does one finish the inside edges of the bulkheads? Some people route them out slightly and fill with micro, others don't. -- bil