Tip-up Frame Re-Dux

Gsuit · #1 06-14-2007, 10:25 AM

Long story short - I'm rebuilding my canopy frame after being unhappy with my original fit, and talking with Van's at Sun'N Fun.

My original fit had a 1/8" - 1/4" gap at the 10 and 2 'o clock positions when closed. After surveying about 60 tip-ups at SNF, it seems this is a VERY common problem. Yet, I did find a builder who built his stock, and it came out perfect (he won best of show, all metal). He said he didn't do anything special, just followed the plans. So, I'm a builder-leper, of sorts, I guess.

This go around I've managed to dodge most of the pitfalls and it fits perfect after center splice plate riveted, gooseneck bars riveted to the fwd channel, and the goosenecks themselves are drilled for the pins.

BUT.... when I added the struts to check the fit (because this is one of the main things that caused mine to go downhill last time) sure enough, I got high spots again at the 10 and 2 'o clock posits!!

Am I crazy? The gap we're talking about, at least this time, is approx. 1/16". Can I fix this later when I do the canopy fwd fillet?

Walt · #2 06-14-2007, 04:37 PM

I seriously fought with this myself and I'm a pretty decent sheet metal guy overall. I had to replace the forward skin once and weld/re-drill the arm holes twice before I was satisified with the fit

LettersFromFlyoverCountry · #3 06-14-2007, 04:42 PM

I don't get it. He followed the plans and didn't end up with a gap? Are you talking about between the canopy side rails (frame) and the deck? Because the plans call for a gap there. They show a gap. WHY they have a gap there I've never quite understood, but they show a gap.

Or are you talking about the skin.

Pictures??

cytoxin · #4 06-14-2007, 06:36 PM

and it can be rolled down or the fwd skin shimmed up. the shimming whic provides better results is some waht difficult due to the taughtness of that skin. i had to roll mine up in the center and down at 10 and 2. the skin was just to ******* tight for shims. YMMV

Pmerems · #5 06-14-2007, 07:27 PM

I posted a while ago about fitting the canopy and that I too had to shim the forward skin to make it fit nice. Though I haven't riveted the forward skin in place yet, I found that I can shim as needed. My gaps were about .040" on both sides.

I used layers of tape (aluminum tap) and created a tapered temporary shim to determine the final shape of the shim. Then I carefully measured and reproduce the temporary shim in a piece of aluminum sheet. Works great.

Rockyjs · #6 06-14-2007, 09:48 PM

I just finished my canopy frame and am getting ready to install the canopy. When the struts are installed they push the canopy frame forward and slightly up causing some bulging at the 10 and 2 o'clock positions. I have seen some stops placed to limit the canopy forward travel during closure preventing part of the bulging problem. I'm looking into placing some delrin blocks cut on an angle that would not only stop the forward movement, but would also slighly push the forward canopy frame rib down and out. I can remove my bulges by exerting some down and out pressure to the skin with my hand, but the problem is how to make a stop to do this. There also is a catch 22 in that the forward skin is not riveted and allows some movement in the sub-panel area. If I come up with a workable stop I'll let you all know.

Gsuit · #7 06-15-2007, 04:43 PM

I appreciate all the responses. I am at least relieved that I'm not nuts... misery does love company. So, I'll press onward and upward with building, hoping the shims on the fwd top skin do the trick.

Scott at Van's mentioned I might try using a ratchet strap to get it a bit over-torqued at 10 and 2, then do the fwd canopy fillet. Once that sets, his logic is that the fiberglass will help hold it down, in place. And the fiberglass will have enough flex so as not to crack.

Thoughts?