Cabin frame shrinkage

Flying Scotsman · #1 12-25-2009, 03:10 PM

Well, despite my best efforts and a crapload of clamps and whatnot, my cabin frame (7A) managed to shrink up just a touch. It's about 1/8" too narrow per the plans. I can think of two options: center it, mark the locations of the 631 channels that bolt to the fuse, and then drill them accordingly, or drill the 631s per the plans and try to stretch or elongate the frame itself. First option seems most reasonable, but I think I'll need to add a shim on each side to make up the 1/16" gap at the forward end of the 631 (otherwise the skin will have a "joggle" in it).

Anyone see any issues with that viz-a-viz the canopy or the canopy frame? I'm going to be Sikaflexing the canopy and rear window...

jsharkey · #2 12-25-2009, 03:42 PM

I used an 1/8" aluminum rivet from Home Depot as a shim under the rear window at the first rivet from teh bottom on the roll bar.

Jim Sharkey
The other flying Scotsman
RV-6 Phase 1 - slowed due to work, weather and flu

Flying Scotsman · #3 12-25-2009, 03:50 PM

That's it! Not quite as much on mine, but same problem.

I think maybe a thin rubber spacer under the window during Sikaflexing would do the trick there.

jsharkey · #4 12-25-2009, 05:13 PM

....natural taper on the side rail so you have to shim or let the skin joggle. The gap was too big on mine so I shimmed. It works great.

One thing to be careful of is catching the edge of the lip on your clothes when "embarking" and "disembarking". It's a good idea to round it off

Jim Sharkey

Flying Scotsman · #5 12-25-2009, 07:59 PM

Thanks, guys...after a gazillion test-fittings and positionings and double-checking and triple-checking all the measurements, once I finally drilled the channels to the fuse and bolted them down, the gap came out very small, indeed. Will just need a piece of aluminum sheet the same thickness as the bottom skin!

I never cease to be amazed at how well everything works out and fits together on these planes...