Canopy frame fitment trouble

[ged380]

I am trying to fit the canopy frame on my 7 tip up and am having a lot of trouble. The biggest problem appears to be on the top where the skin on the canopy frame sits higher than the fwd fuse skin. This looks terrible and I'm not sure how to fix this problem. Also the frame appears to be too wide and the skin bulges out on the sides. I am sure this is a common problem and I'd like to hear what people have done. I did search and found a few threads but one really addressed the problem I am having on the top skin.
Any help would be appreciated.

 

[jsharkey]

On my RV6 the fwd skin was higher than the canopy skin so I shimmed the top of the canopy frame with strips of aluminum to even out the step. Can't find pics but I did make hand sketches in my build log book.
Jim Sharkey

 

[Mike F]

I'm wrestling with similar issues. Look for interference that keeps the assembly from sitting flush, expecially around the weldement hinge points.

This is hard to explain without pics but is it possible one of your clecos (hinge arm vicinity) is sticking through too far and is pushing the hinge arm down? It's free to move around at this point but if it gets pushed down too far, the hinge will hit on the bottom of the cutout in the subpanel, forcing the entire assembly to sit high. I think Dan's website talked a little about it. Even after removing the cleco, I still had to deepen the cutout with a file a little bit.

If you need some pictures to explain it better, let me know. [Update] I found a pic...

http://www.rvproject.com/20030302.html

 

[Norman CYYJ]

Don't worry too much about it, if there is nothing that you can see that is holding the skin proud. Have a careful look at it once it is all riveted together. You will be surprised at how things change. If you still have a proud skin you can build the other skin up with epoxy and sand it flush, just make sure that you rough up the AL with course sandpaper first or it will not bond that well.

 

[Pmerems]

There are a few previous posts on this subject

Do a search on this subject and you will find other postings dealing with this trouble spot.

I too had issues and shimmed the front top skin to improve the fit. I believe there is a profile mismatch between the frame and the bulkheads and it never has been corrected.

Food for thought.

Paul (RV-7A finishing kit)

 

[Gsuit]

About a year ago I had the same trouble. At Sun 'N Fun I set out to view and photograph as many tip-ups as I could to see how common this issues was. Out of 23 tip-ups, 22 had visible issues at the same 10 and 2 positions. Only one guy managed to get his perfectly smooth. When I asked him how he did it he said it took him quite some time - and he did it with shims.

That's how I did mine, and it does work. After you make sure there is zero interference with the left and right aft sub panel flanges, the center seal strip and the frame wasn't drilled with a 'sag' at the center splice plate - mark on the frame skin where the it bulges. Then make shims to go under the forward top skin in the marked locations. Be sure to taper the ends of the shim for a smooth transition, and start with .032 shims. Match drill to the sub panel forward flanges.

I would wait to do this shimming after you have completed the canopy, since it will be the forward skin you will make match your frame skin - and the top forward skin will be one of the last installed. Plus, as you add the struts and the canopy forward fairing, the frame will stiffen up significantly. The bulges won't necessarily go away, but they may change somewhat.