From: ponciroli@postoffice.worldnet.att.net Date: Fri, 7 Jan 2000 10:48:14 -0500 Subject: COZY: Fuselage Top Installation Builders - Maybe I'm taking these plans too literally, however I found a flaw in the way the plans describe how to align the hinges that hold the fuselage on over the instruments fwd of the instrument panel. When I finished doing what was described in the plans, the inside of the doubler and the longeron aft of the instrument panel didn't line up. Chapter 18 Page 10 Fig 54 shows the doubler going from f-28 back to the inst. panel. The doubler in Fig 54 shows that it provides a flat surface for the hinge. If it ended there, that would be true, but hinge also extends aft of the inst. panel about four inches, for a total of 17 inches. The fix is simple. measure from F-28 back 17 inches and mark the longeron. Then carve the doubler to fit the longeron and do another for the four inches aft of the inst panel. Leave some wood so that you can later draw a straight line. Then, on the fwd doubler, measure from a point (1/2 inch inboard from the longeron towards the center of the airplane at F-28) and put a straight edge from that point back to the mark previously marked on the loneron and draw a straight line. Now you have a line that will allow you to insert the 17 inch hinge pin. Date: Sat, 08 Jan 2000 09:13:26 -0500 From: "L. Wayne Hicks" Subject: Re: COZY: Fuselage Top Installation ponciroli@postoffice.worldnet.att.net wrote: When I finished doing what was described in the plans, the inside of the doubler > and the longeron aft of the instrument panel didn't line up. -------> I had the same thing happen to me too. To get the hinge line straight, I did what you did and simply floxed a small doubler (it looks like a small shim) aft of the instrument panel. I wouldn't call it a flaw in the plans, though. This is homebuilding and you gotta do what makes it work. The curvature at that very spot all depends on how hard you clamped the longerons back in chapter 5. It's quite possible that Nat didn't have to do this to his original prototype and plans-conforming planes. Wayne Hicks http://www.geocities.com/yosemite/falls/2027 From: Epplin John A Subject: RE: COZY: Fuselage Top Installation Date: Sat, 8 Jan 2000 08:36:29 -0600 > ponciroli@postoffice.worldnet.att.net wrote: > When I finished doing what was described in the plans, the inside of the > doubler > > and the longeron aft of the instrument panel didn't line up. > [Epplin John A] I think that is the way it is supposed to be. Mine does not line up but the pin goes in OK. There are two distinct parts on each side, they are aligned in one plane, but not in a plane 90 deg to level. If you look closely, you will see that as the pin comes out of the rear most section, it will enter the forward section at a slight angle. This appears to be as intended, the pin will flex enough to go into the forward section without any undo force. John Epplin.. Mk4 #467 From: "John Slade" Subject: COZY: Ch 18 - canopy tint and night flying Date: Thu, 27 Jan 2000 20:48:51 -0500 Builders, I've checked the archives and there isn't much discussion on the impact of tint on night flying. I called airplane plastics and they say they sell 98 medium tint for every 2 light tint. I expect to do quite a bit of night flying. Most operations will be in under the Florida sun. Can anyone provide input on what night flying is like with a medium tint canopy? Regards, John Slade, Cozy MKIV #757, progress: http://kgarden.com/cozy West Palm Beach, FL Date: Fri, 28 Jan 2000 14:29:03 +0200 From: "Rego Burger" Subject: COZY: Ch 18 - canopy tint and night flying For the record.... I flew in a KR-2 on afternoon with a fellow EAA'r in Port Elizabeth. 1.) nice sun shade. 2.) flight time thief. 2.) The story: Airborne 15:30 zip zap, roll or two , buzz her buzz there, oops it's geting dark, time to go home. Land at 16:45 open the canopy and HEY! there's still an hrs. flying time.....?????? It was a pretty dark tint... so for me no thanks... that's really day-light robbery! If you think you may be home late one day keep it clear...the canopy that is. Régo Burger Tel: 0800456789 Fax:+27 41 3631465 South Africa From: "Todd Carrico" Subject: Re: COZY: canopy seal Date: Thu, 27 Apr 2000 10:48:56 PDT Here is a detailed account of a LongEZ modification, but it may give you some more insight into the problem. tc http://www.canard.com/articles/9802/kreidel.htm ----Original Message Follows---- From: "Butler, Dennis S" Reply-To: "Butler, Dennis S" To: "'cozy_builders@canard.com'" Subject: COZY: canopy seal Date: Thu, 27 Apr 2000 09:12:44 -0500 All -- Is anyone flying with a canopy seal that does not leak? If so, please advise me how you did it. I'm about to install the canopy/turtleback on my 3-place cozy, and, as far as I can tell, suggestions on how to do it range from adding a 'few layers of duct tape' to the longerons to produce a gap for a seal (Newsletter 57-10) to putting a groove in the underside of the canopy, to leaving a 1/8 inch (minimum) gap for weather-stripping (4/20/00 Cozy forum). All of these suggestions make sense to me, but have any of them actually been tested by flying in the rain yet? thx -- Dennis ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com From: cdenk@ix.netcom.com Date: Thu, 27 Apr 2000 17:21:53 -0400 (EDT) Subject: Re: COZY: canopy seal On the way home from Sun N Fun, was the first time that wife and I felt a few drops of rain on our knees. Probably the seal across the front of the canopy needs replacing after 6.4 years and 800 hours. Its hollow quarter round, but remember my canopy is forward hinged. Along the sides I have "P" strip, and the hollow quarter round along the aft edge. With the plane parked nose down, we might get 4 or 5 oz. of water on each side after a hard rain. That is coming through the elevator offset (MKIV type) holes. Apparently water flows off the canopy/fuselage, down the backside of the canard and finds the gap. I have small gutters on the inside, but they don't help that much. Possibly by surface tension the water is actually sticking to the offset. From: "Keith Scull" Subject: Re: COZY: Canopy bubble edge Date: Fri, 9 Jun 2000 11:36:25 +0100 Dennis I achieved a near perfect edge to my transparencies using a product that is made of semi hard wax, it is available here in the U.K and is sold in sheets approx 20" x 10" and in a range of thickness from 1mm to I think 8mm or so. my method was very similar to Wayne's but instead of using duct tape I used the wax which is much easier and very much better (having tried the tape method). What I did is cut the wax into 3/8" strips using a craft knife, the wax has a self adhesive backing on one side which sticks it directly to the transparency, when you come to a corner you simply bend the wax strip to conform to the radius of the turn and press it down to the transparency. I then filled the gap between the lay-up and the wax (very small) with a mixture of resin and silica with a little flox, using a metal scraper I removed the excess filler leaving a top face that was completely smooth and only required flatting off for painting. When the filler had cured I removed the wax strips which leave a sharp clean edge to the filler. the result is a very very neat edge that conforms exactly to the shape produced by the was strips. Sounds complicated but is extremely easy and only takes a few minutes to do. The product is known here in the U.K as "High Temperature thermal stable wax sheet" it's primary use is to produce depressions in moulds for glass lay-ups. The range of thickness available allow many size recesses and edges to be made very easily. Regards Keith Scull Best of luck with your project. cozy MK1V second in the U.K flying this year (I hope). ----- Original Message ----- From: Wayne Lanza To: Butler, Dennis S Cc: Sent: Thursday, June 08, 2000 1:57 PM Subject: Re: COZY: Canopy bubble edge > Hi Guys, > Regarding the edge of the glass to Lexan on the canopy, > I've used the following technique and recommend that it > be considered. Use three plys of duct tape split in half, > (that is 1" wide), use shorter pieces where sharp turns are > needed and butt edge the pieces of tape. Do this one ply > at a time carefully getting the edges even for each layer. > Avoid cutting the curves you will leave a small score in > the bubble that might haunt you during finish. After this > is complete extend from the "edging" tape with some wide > strips for canopy protection. Carefully sand the plastic with > fine sand paper as close to the tape as possible. > To 'glass the edge, go to your cloth scraps and cut pieces > of UNI (not bid) about 1" wide from the original "selvage" > edge of the roll cloth. Apply 2 layers of the UNI strips in > small sections butting their ends and forming the woven edge > to meet the duct tape. Next apply 1 layer of bid cutting it's > edge to meet the back edge of the UNI plys. Finally apply > a second layer of bid over the whole mess, cutting it's edge > close to the duct tape. When cured, LEAVE the duct tape in > place and start sanding the glass. You will disturb the upper > layer of the tape but shouldn't go all the way through. When > finished, pull a short section of the tape to find a neat edge. > > This method is really easy and doesn't take a lot of time to do. > The edge is a very noticeable part of your finish work, take the > time to get it perfect - regardless of how you do it! > > Best Regards, > Wayne Lanza > aka Composite Design, Inc. > > Date: Thu, 26 Oct 2000 22:22:40 -0700 From: Jim White Subject: COZY: Straightening Rear Edge of Canopy Turtleback Hello All, The rear right edge of my canopy, betweeen the two side windows, no longer matches the countour of the stationary part of the turtleback. I believe the out of countour shape of the canopy/turtleback was caused by the stress of the middle plexiglass window. The middle side window did not perfectly match the curve of the turtleback until after I Clecoed it in place as per Figure 19 on page 3 of Chapter 18. The rear contour of the canopy sticks up approximately 1/4" above the rear turtle back section along the right side. I have seen this on other Cozy's and am wondering how some of you corrected the problem. I can think of two ways to solve the problem: 1. Apply heat to the turtleback and middle window to "bend" them to shape, or 2. Construct a small jig to hold the rear canopy edge in the proper shape and then fiberglass a slight lip on the rear edge of the canopy that will fit into the drip rail when the canopy is closed. Once I remove the jig the rear edge should stay in place. Let me know if any others have had this problem and how you dealt with it. Many Thanks in Advance, Jim White N44QT From: marc_zeitlin@agilent.com Subject: COZY: Straightening Rear Edge of Canopy Turtleback Date: Fri, 27 Oct 2000 07:42:03 -0600 > jimwhi@mciworld.com writes: > > I believe the out of countour shape of the canopy/turtleback was > caused by the stress of the middle plexiglass window....... Well, now that Todd and Steve have told you (in good USENET fashion, instead of answering your question) that you should have purchased different windows :-), I'll have a go at actually answering your question. I used a pre-fab turtleback which (until I cut it for the canopy/TB interface) obviously lined up perfectly. It also lined up perfectly for the first year or so after installing the windows. However, after a year or two of storing the canopy OFF the fuselage standing up, I think it warped a bit. When I installed it again to do the strake fairings and canopy lip, I found that the canopy/TB interface line had mismatches of up to 1/8", both high and low. What I did (since this is NOT a structural area) was to take my belt sander and sand down the high areas until I got a smooth match, ensuring that I didn't extend the sanded area more than 2" from the interface line. I then laid up 2 BID over the bare foam, lapping 1" onto the TB and canopy glass. I'm now ready to layup the 4 BID canopy lip, and then I'll micro the whole area and sand flush and smooth. With your 1/4" mismatch, you might be able to do the same. -- Marc J. Zeitlin marc_zeitlin@alum.mit.edu http://cozy.canard.com Non Impediti Ratione Cogitantonis (C&C) From: "Bill Kastenholz" Subject: Re: COZY: Straightening Rear Edge of Canopy Turtleback Date: Fri, 27 Oct 2000 11:08:14 -0400 Hi Group, Marc responded: >What I did (since this is NOT a structural area) was to take my belt sander >and sand down the high areas until I got a smooth match, ensuring that I >didn't extend the sanded area more than 2" from the interface line. I then >laid up 2 BID over the bare foam, lapping 1" onto the TB and canopy glass. >I'm now ready to layup the 4 BID canopy lip, and then I'll micro the whole >area and sand flush and smooth. > I knew you could build one of these machines with just a squeegie and a belt sander. When I built my canopy, I raised the front of the TB by 1 1/2" to get the greater headroom and smooth transition on the the top. When installing the windows, I placed according to the curvature of the TB. I was upset after seeing how nicely aligned most people had the bottom edge of the front bubble and the bottom edge of the windows(very esthetically pleasing). Now, I think maybe I lucked out with my window placement; I don't see much warpage, just a very tad high on the canopy side after all hinge work and latches done. Also, a point made to me by Dennis O at the big O. The Cozy3 has a rib on the inside aft section of the canopy, while the Cozy4 does not. He thought it would be good to stabilize the canopy from lifting in flight with the same type rib. I incorporated this idea into my canopy and it may help stabilize the shape. Hope these ideas may help somebody coming up on this chapter. Jim, I believe Marc's solution is probably a good one in this case. Belt sand away!! Bill Kastenholz Date: Sat, 28 Oct 2000 00:07:50 -0400 From: "Marc J. Zeitlin" Subject: COZY: Straightening Rear Edge of Canopy Turtleback Todd Silver writes: >Is that easier than just replacing the windows which introduce stress on the >turtleback with ones that don't? You bet. Installing the windows took a LONG time. Digging them out and re-installing would be a pain. Belt sanding took 20 minutes, and laying up 2 BID strips took another 1/2 hour. I've got to do the microing after the canopy/TB lip anyway, so there's no extra time there. > ..... If one installed windows which perfectly >matched the compound curve of the turtleback, would that not be the solution >to Jim White's problem? You bet - that would be the perfect solution __IF__ it were the known cause of the problem (which it _wasn't_ for me - my windows were not stressed at all when I installed them) and if the windows weren't already installed. > ...... Is there something more to it than that? Just the ever present tradeoff between time, quality, and money :-). Replacing the windows would be SLIGHTLY better quality, but would cost more and take a lot longer. Those of you who are perfectionists - go right ahead and follow that path - I'll ooohhh and aaaahhh at Oshkosh at your bird, while you laugh at mine :-). Of course, if you haven't yet installed windows, ensuring that they're not stressed at assembly is a good idea. I'll venture a guess, though, that the canopy bubble itself (and thermal expansion variations between it and the canopy/TB material) are causing most of the problems, along with creep of the canopy/TB glass under gravitationally induced stresses during storage. My $0.02. -- Marc J. Zeitlin mailto:marc_zeitlin@alum.mit.edu http://www.ultranet.com/~marcz/ Date: Fri, 27 Oct 2000 23:16:58 -0700 From: Jim White Subject: Re: COZY: Straightening Rear Edge of Canopy Turtleback I started this thread and hopefully I can end it. I plan to go with option 2, similar to what Bill Kastenhotz described as installed on the Cozy III, that is, install an internal rib along the back of the canopy that fits within the drip rail. I will build a temporary jig on the outside to hold the shape I want until the epoxy cures. A slight pressure is all that is needed to keep it into the position I want. I take full responsibility for the shape of my side windows since I molded them myself. I molded my own windows since my turtleback is lightly wider in the back than the plans version. In spite of the slight bulge that developed, which will be restored to perfection, the windows are smooth and perfectly flush with the turtleback contour. I completed the side window installation over three years ago, and am now at the final contouring and finishing stage. I have no intention or need to replace the window. Thanks for all your input, Jim White N44QT Date: Sat, 28 Oct 2000 08:45:24 -0400 From: Jeff Russell Subject: Re: COZY: Straightening Rear Edge of Canopy Turtleback "Marc J. Zeitlin" wrote: > I'll venture a guess, though, that the canopy bubble itself > (and thermal expansion variations between it and the > canopy/TB material) are causing most of the problems, along > with creep of the canopy/TB glass under gravitationally induced > stresses during storage. I have installed quite a few canopies and it seems that the ones that were trimmed and installed in the winter months change the shape MORE than the ones installed and trimmed in the summer months. Could be the relaxing of the cell cast acrylic when it gets warmer? That's my best guess, but I am sure that the acrylic is what is pulling and expanding and making the mis-match after time goes by. -- Jeff Russell/AeroCad Inc. Website: New info... http://www.Aerocad.com Sponsor- Canard Aviators From: "John Slade" Subject: Re: COZY: Straightening Rear Edge of Canopy Turtleback Date: Sat, 28 Oct 2000 06:05:34 -0400 That's interesting, Jim. I have exactly the same problem, presumably for exactly the same reason. I also draped my own side windows because I made my side windows larger than plans. They had the correct contour and I didn't have any trouble fitting them. When I did the initial finishing on the Turtleback (last summer) the canopy fit perfectly. Now it's about 1/8 to 3/16 out on one side. I'll probably use the same solution as you. I hope our canopies still fit next summer. There's no way I'm digging those windows out and installing new ones. By the way - I have some overspray and a few minor scuffs on my acrylic. I got a small pack of the Micromesh restorer which comes with liquid abrasive and 1500 - 6000 grit wet & dry paper. I'll let the group know how well it works. Regards, John Slade, Cozy MKIV #757, progress: http://kgarden.com/cozy West Palm Beach, FL From: "Nat Puffer" Subject: COZY: canopy installation Date: Sat, 28 Oct 2000 08:30:31 -0500 Builders, The acrylic bubbles we use in our canopies shrink as it gets colder, and tends to raise the front of the canopy frame. This is a lot more pronounced with the Varieze and Long EZ because their bubbles are much longer than we use on the Cozy. If you build your canopy frame at room temperature, or elevated temperatures in the summer, you will find that the front of your frame will raise slightly as you climb to altitude where it is colder (but this is very difficult to see from inside the cockpit). Vance Atkinson (that clever fellow) made the top of the fuselage ahead of the canopy frame about 1/8 inch higher, so that when he climbs to altitude, the canopy frame lines up with the top of the fuselage. The affect of shrinkage on the alignment of the frame is so slight though that most builders don't worry about it. Regards, Nat