Tip-up forward canopy frame skin fit

I have my canopy frame hinged to the fuse and the side rails attached now. At some point I need to finish drilling the remaining skin to frame holes, but there is a large gap between the skin and frame on both sides for the upper row of rivets from front to back (the ones that were not pre-punched in the frame). I am pretty sure this is common, so how have others fixed this?

If I remove the lower clecos, I can get the skin to lay down nice, but then the lower holes are off by as much as 1/16" on the aft end. Adding spacers seems very difficult given the length and the taper required.

Van's suggested making individual spacers for each of the holes. It will be a little time consuming, but it should work okay.

Tapered shims

I made a single tapered shim for each row that closely matched the necessary contour. That way you still get a nice smooth curve and not "steps" between rivets. Better for both aesthetics and strength. Wasn't that hard to do.

In the photo below you can see the various shims I made as they are gold colored (alodined) whereas the rest of the frame is green (epoxy primer). They're too small in the photo to see the taper, but yes, they are all tapered to match the natural curve of the skin.



http://www.kalinskyconsulting.com/rvproj/canopyframe.htm

roee said:

I made a single tapered shim for each row that closely matched the necessary contour. That way you still get a nice smooth curve and not "steps" between rivets. Better for both aesthetics and strength. Wasn't that hard to do.

In the photo below you can see the various shims I made as they are gold colored (alodined) whereas the rest of the frame is green (epoxy primer). They're too small in the photo to see the taper, but yes, they are all tapered to match the natural curve of the skin.

http://www.kalinskyconsulting.com/rvproj/canopyframe.htm

Click to expand...

I like the "really big dimple die" that you made . How'd you chamfer the inside of the female half? I'm about to start on the frame, and want to make these lightening holes look nice...

Flying Scotsman said:

I like the "really big dimple die" that you made . How'd you chamfer the inside of the female half? I'm about to start on the frame, and want to make these lightening holes look nice...

Click to expand...

Glad you liked it . Nothing exotic -- I used a 45 deg chamfer router bit from Home Depot to chamfer both the male and female halves. And I don't have a router so I used it in my drill press. Worked like a charm.

I don't want to sidetrack this thread, so if you have further questions on the "really big dimple die" you can start up another thread or email me off-line and I'll be glad to answer them.

I used "liquid shim", that is Devcon aluminium epoxy. I clecoed the skin where it did fit which was only a few places with Devcon in between and waited for it to go off enough to remove the skin.(used glad wrap on the skin because it was already primed). Worked a treat.
I actually had quite a spirited discussion with Vans about the poor quality of this weldment, but apparently they dont intend to do anything about it.

Thanks for the ideas, these are both great. I also checked out a friends canopy last night and noticed that he was able to push the skin up some, creating a larger gap only above the tube (over the last three holes I believe). My gap is too large for that to work, so I will either add spacers, or fold the skin down and re-drill the pre-punched holes in the lower set with a backing plate to compensate for the ovaled holes.

Right now, I am primarily considering the later, as it allows for another anoying fix to the triangler hole that forms under the skin where it buts up to the side skirts. I will see if I can add a picture later to explain better. It will require some creative filing of the side skin, but fixing 2 for 1 is always good.

They must have changed something, because that part on my 6 was a perfict fit.

I just wanted to follow up on this thread as to how I fixed it incase someone needs another idea in the future. I decided to re-drill the lower pre-punched holes in the weldment which allowed my skin to lay flat and cover the triangular hole that many have fixed in other ways. Not ideal, but it will look good.

I used 3 'air' rivets on each side to plug the holes in the skin. My gap was about 3/8 inch. Figured when the canopy was glassed in the skin would be stiff enough. The fit of my frame was real bad. I had to add curve and shim the front to match the forward top skin. I can't open the canopy inside my garage with an 8' ceiling either. That and having the hinge line over my avionics makes me wish for a slider...

Hint..move the side skins forward to make the triangular hole smaller on each side...

I am not filling the holes. Not sure what I'm going to do later, but they might come in handy attaching a piece of carpet?