Canopy frame help needed...

[LifeofReiley]

Originally Posted by Lars

If it's any consolation, I've fitted 3 of them now- and in each case, the aft bow was asymmetrical as received. The arc of the passenger half was substantially different than the pilot side. If memory serves, the passenger side had a tighter arc than the pilot's side, and all were the same. Verified by tracing the bow on a big piece of paper, then flipping the paper over and setting the bow back on it.

I spent a ridiculous number of hours trying to straighten mine, the first one I worked on, solo. I was ready to turn it in for the scrap metal value one day, when I found myself in the hangar with a couple of insightful helpers (they were helping me drink my beer). I had previously cut some arc shapes from pieces of 2x4 that I was using as forms/bending jigs, and had them bolted to a table. About 45 minutes after the inspiration to get it straight, once and for all, we were done.

A long-winded way of saying that this is one place where help is very helpful.

The Arc is tighter on the Co-Pilot side and you leave it alone... the whole set up is fabricated this way to include the front of the canopy frame and the bubble. It will fit up correctly and match... your fiberglass wrap covers this area anyway.

[scrollF4]

Originally Posted by gasman

Sounds like a slider.......... We don't have that problem with the tilt up........

Too right. We have totally different types of utter frustrations with the tip-up. If the Mothership is listening, in my book if there's any one area where the kit's components just don't match the high level of "constructability" we enjoy in the rest of the kit, it's the canopy frame (at least on the 7 and 9).

If you guys need a hobby out there in Aurora, well, this has my vote...please fix the canopy.

Having said all that, I am tremendously grateful for this aircraft and the chance/challenge to build.

[jay.pearlman]

I finally gave up on just bending. The lengths of the rear frame legs on the slider were asymmetrical. Got a good welder to work with me. We cut the rear bow on both sides at the bottom, shaped everything - by heating the rear bows - and then rewelded. Took a couple of hours and now everything fits. Mine was an older round tube frame. Not sure this is the best way for everyone, but it worked for me.

[Lars]

Originally Posted by LifeofReiley

The Arc is tighter on the Co-Pilot side and you leave it alone... the whole set up is fabricated this way to include the front of the canopy frame and the bubble. It will fit up correctly and match... your fiberglass wrap covers this area anyway.

I laid up the entire canopy skirt out of glass & carbon fiber. And yep, it covers a world of little imperfections

Originally Posted by jay.pearlman

I finally gave up on just bending. The lengths of the rear frame legs on the slider were asymmetrical. Got a good welder to work with me. We cut the rear bow on both sides at the bottom, shaped everything - by heating the rear bows - and then rewelded. Took a couple of hours and now everything fits. Mine was an older round tube frame. Not sure this is the best way for everyone, but it worked for me.

The aft bow legs were of equal length on mine, but the curvature was wrong. If I were to build another one for myself, I would probably do the cut/bend/weld approach, since I have access to a TIG and a nice metal fab shop.

[ron sterba]

One of the things I have learned in the canopy process is that the frame should NEVER be bent to fit after welding the 4130 steel! You put STRESS on the weld. (ASK A WELDER) BUT ITS DONE!..... WHY because when the alloy welding rod is melted in the welding process, you have alloys that are molten and then cooled. Its the weakest point really between the 4130 steel tube and the alloys in the weld. Hopefully the two melt together well mixed. Consider the the max perforamce of the the steel tube. All it holds is the plexiglass. Now if it was a structual frame work I might think different about BENDING a 4130 tube that's been welded. (IT STILL BUGS ME TO BEND ANY 4130 TUBE THAT HAS WELDS).I had THREE big guys help bend my canopy frame according to the 9A plans info book using a notched 2X4.. Now if you consider using a straight edge from the rear aft skin adjustment can be made to the adjustment screw on the rail going into the aft bulkhead. Allow the rear canopy rail to be lowered by bending the rail a little at a time. This brings the AFT skin and the rear rail of the canopy to the desired angle of the plexiglass lay up. Think of it like a draw bridge that lifts at one end. The road bed (PLEXIGLASS) needs to be uniform,straight to the skirt and aft skin. I know its easy to say but tuff to do. NOW here is the the way you make the the aft Canopy skirt fit! Pay attention now. If you read carefully in the RV plans.(Read each word!) This should stop you from ordering a second copy of the sheet metal used for that application as I had to READ each word to better understand. On the large panel of the alluminum that you will cut the TWO aft skirts out of, look closely the pattern is outlined by VANS. This makes cutting out easy. BUT wait! What I want you to do is MAKE a stencil or cut out of this outline by VANS on tracing paper and set it aside. Now cut out the two pieces that you will use for the aft skirt making it piece the largest it can be be. That is trim each piece oversized but a least half inch or more providing the the Allumium is big enough. Install the plexiglass to the frame. Make sure your canopy frame is in the closed position. Now lay one of the pieces over the aft plexeglass at the rear canopy rail and the aft skin. Pull both ends tight and that the WHOLE piece lies FLAT on the aft plexiglass/canopy rail and the aft skin. YOU will notice that the panel is slightly off center but FLAT! This is what you want in the aft skin. Its to lay FLAT with no gaps. Have afriend hold the panel flat and take your stencil that you made and lay it on the the panel and tweak the stencil to the position that make the panel uniform according to the specs for positioning from the plans. Tape the stencil to the metal panel. Trace this out. This is where you find out that the ORGINAL outline from VANS plans on that panel was slightly turned. Its this procedure that matches YOUR BUILD in the frame and fuselage alignment. So go ahead now and trim out that panel. It should MATCH UP.

Ron in Oregon.QB9A Hope it makes sense.