Tip: Canopy Woes and Tips

Just thought I would share a little "gotcha" with other poor souls about to start on their slider canopy. I was about 60 hours into my RV9A slider-- my canopy was cut, match-drilled to the frame and fitting quite well. At that point I was fitting the windshield and noticed a slight hump on one side where the canopy roll bar and slider frame meet. I foolishly thought "I can tweek the frame a little and make that perfect." The instructions even mention several times that you should adjust the frame. To make a painful story short, once I started bending, everything got worse, leading to more bending, then a loud snap when the canopy frame broke cleanly in two at the site of one of the holes. When I called Van's about the problem, I was informed "don't bend the frame once the holes are drilled." I had it welded back together but the fit is now terrible. I'm now waiting on a new $350 frame from Van's. I've enjoyed everything in the build process until this.
Steve Johnson
RV9A
Abilene, Texas

Canopy frame

I have a tip up but my neighbor is building a 7 slider and suffered the same deal down to the last detail. He said the instructions say to tweak it as necessary. Tried welding, no good. New frame!!!!

I am convinced Van's makes no money on the original kits but on the mass of parts we screw up.

Darwin N. Barrie
Chandler AZ
RV-7 N717EE flying

Jim here went through this recently. Check out his site...

http://rvpilot.com/RV9ACanopy/CanopyIndex.htm

-Jeff

Canopy update

Just an interesting update. I received my new replacement canopy frame from Vans. In less than 2 hours it was fitting pefectly (I spent about 25 hours on the old frame). I had to drill new holes in the plexi along the aft bows as these frames are all different (lightening holes?). Finally, I am on to something new!
Steve Johnson

Canopy fit problems explained (partly)

After fitting my canopy, and helping others fit theirs, I've seen two cases:

a) everything fits reasonably well.
b) nothing fits well.

I had a theory that even though there were manufacturing variances on the frame, that some or most of the error could be in the fuselage construction.

Evidence supporting this is that some of us had large 'fish-mouths' on the back of the side slider rails, had to cut and weld the canopy frames or trim the fuselage skins (or all three).

Today, I saw a canopy frame with an almost perfect fit, and no fishmouth at all on the slider rails (and not even any bevelling required). The builder, however, complained that he had to bend the roll bar in by 3/8" and remarked how difficult this was.

We measured the fuselage at two points... one at the seatback brace, and the other at the roll-bar attachment point. The aft measurement was spot-on at both points, but his width at the roll-bar point was... 3/8" narrower than on my fuselage!

All of his skins fit fine, his panel blank was installed, and his canopy frame fit well.

Now, my fuse was a QB, and his was a kit-build. When I received my fuse, there was a brace across the fuse near the roll-bar attachment point.

Looking at my friends fuse, I could see how it would be possible to build it with this point narrower... there is no support during construction that establishes this dimension.

If this dimension varies, then the whole canopy fit will vary. This is a large variance that's impossible to correct for with any amount of bending and twisting.

Based on this evidence, I suspect that this is the root cause of many canopy construction woes. I'll contact Van's to determine what the correct width is at the roll bar attachment point, and post it to the list.

Vern Little
9A

slider canopy frame

The back bows on my slider frame do not conform to the turtle deck skin, as it looks like it was welded at a slight angle; therefore the left side is lower than the right by about 1/4 inch measured 8 inches from the center of the frame, while the right side is 1/4 inch higher. Trying to bend this to the proper dimentions has been impossible. Any suggestions???

Thanks,
Ken