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Old 03-09-2010, 08:11 AM
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sensei
 
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Default RE: Ace Extra 230 33% Fiberglass


ORIGINAL: SticknRudder

I've got a problem - it's been a month since I've worked on the airframe (due to bad weather) - been storing it in the furnace room to keep it at a more or less even temperature and humidity and found that it's developed a 1/4'' twist over it's 54'' length. In addition to that, it's developed about 3/16'' sag from F-1 to F-3 (~20''). I think I could have avoided most of this if the sides plates were epoxied to the spars immediately after I had all of the formers and spars set. I had it sitting on the firewall with the frame vertical - not like it was laying over anything causing it to warp.

Now, short of soaking the airframe in the hot tube and re-fixturing it to the rail and letting it dry out, does anyone have a solution or recommendation? The airframe can be very easily persuaded back to square and plumb with minimal effort since this problem involves only the 1/4'' longitudinal spars at this point. I'm sure that attaching the side plates will eliminate the sag, but not so sure about the twist.

Please let me know what my options are.....or if this is more or less normal.

Thanks
I would place it back in the fixture you used to build it, true it up and add 3/8" x 3/8" Medium density balsa diagonals on the top and bottom of the fuse, make sure that they fit with no pre load and bond them in, this will keep your fuse from ever twisting.

Bob