Date: Sun, 20 Feb 2000 21:02:58 -0700 From: "Capital Steel Inc." Subject: COZY: Sides and upper longerons Hi Rick Maddy, At this point I had not been careful to have only nailed the masonite to the forms at the point of contact so the lower back does not look too good and requires more work later. Start by weighting the masonite on FJB and FJD first. As I recall the front and rear are not quite square, but they get trimmed later anyway. The instructions don't say but be sure to mark where you want the front doubler to start. Mine ended up about 0.25 too far aft and had to be repaired. When you get to this point your longerons should be close enough to seal in place without flox. For clamping I used 1" pieces from a bicycle tube and some pieces of 5/8" square wood about three inches long. By putting the square of wood through the section of tube I could put it between and under then turn and pull up and put another piece through on top over the longerons to hold them in a close fit. About 10 of these went in quickly and could easily be located just where needed without deforming the edge of the masonite and without interference with the 7/8 spacers. If I still had trouble I would go for sanding the foam but I didn't. Joe Date: Mon, 21 Feb 2000 08:56:32 -0600 From: Michael Pollock Subject: RE: COZY: Fuselage Sides and Upper Longerons Rick Maddy wrote: >Please let me know what you did. Rick, I simply made small cuts into the bottom longeron corners as Nat describes in step 5 of chapter 5 to allow the longeron to form to the fuselage side. Clamps were then used to secure the longeron to the fuselage side using plenty of flox. I seem to recall that I made several small ~3/8" cuts every 3" - 6" along the longeron where it did not want to conform. If you made your fuselage side jigs correct and the longeron jigs correct, this method works fine. I would not remove any foam from the sides to make the longeron fit. Make the longeron fit the side. Good luck.. Michael.Pollock@wcom.com Flying Velocity N173DT Building Cozy MKIV #643 -----Original Message----- From: owner-cozy_builders@betaweb.com [mailto:owner-cozy_builders@betaweb.com]On Behalf Of Rick Maddy Sent: Sunday, February 20, 2000 4:47 PM To: Cozy Builders E-Mail List Subject: COZY: Fuselage Sides and Upper Longerons Warning - this mail contains some possibly nitpicky geometry details :) I'm wrapping up step 3 of chapter 5. I have made the upper longerons, I have the sides in the jigs, all the foam spacers are in place with all the correct bevels. I have made the depressions for the control handles. In preparation for glassing the sides the plans suggest testing the fit of the upper longerons. This is where I ran into some questions. All my issues stem from the fact that the forward edge of the fuselage side is parallel to the workbench while the aft end is not. 1) Since the aft bottom corner is higher than the aft upper corner, the longerons can't lay flat. Basically the fuselage has a twist in it on the aft 1/3rd of the length. The longeron does not have this twist in it. When I lay the longeron in place it fits perfect on the forward 2/3rds of the length. However on the aft 1/3rd the longeron only touches the foam on its bottom edge. The top edge is about 0.07" off the foam at the aft end. That doesn't sound like much but it is. I see several solutions. One is to use flox to fill this gap. Another is to try to twist the longeron to match the fuselage (not likely). Lastly is to sand the foam to counter the fuselage twist. The flox solution seems to be the most likely. 2) The same twist also causes the gap between the fuselage sides' top edges to be closer together at the aft end than at the front end. The masonite gap is fine but the top edge of the foam is closer. Since the top of the longeron is supposed to be straight (W.L. 23) do I just sand the top of the foam a bit to make it even? Please let me know what you did. Thanks, Rick Maddy (mailto:rick@maddyhome.com) Cozy Mk IV #0824: Chapter 5 (http://www.maddyhome.com/cozy) From: Fritzx2@aol.com Date: Mon, 21 Feb 2000 22:40:49 EST Subject: Re: COZY: Fuselage Sides and Upper Longerons > 1) Since the aft bottom corner is higher than the aft upper corner, the > longerons can't lay flat. Basically the fuselage has a twist in it on the > aft 1/3rd of the length. The longeron does not have this twist in it. When I > lay the longeron in place it fits perfect on the forward 2/3rds of the > length. However on the aft 1/3rd the longeron only touches the foam on its > bottom edge. The top edge is about 0.07" off the foam at the aft end. I would vote for just weighing down the longerons and let the flox make up the difference. An important part of this step is to make sure that the longerons are parallel to each other so that after you have mated the sides to the bulkheads, a flat surface like a level when placed side to side will rest and touch across all the longeron surface. That's why the plans say to insert spacers all the way along. As long as the spacers are all the same thickness and then clamped in between the two longerons, the longerons will be parallel to each other. John Fritz fritzx2@aol.com