flyenforfun

flyenforfun

Well Known Member
Another day of screwing with the canopy and I walk away frustrated, no further along than I was this morning. Id take pictures but they wouldnt help. Im not sure how to even explain whats going on with this thing.

First off I think I cut the front too high. have a small gap there which I read isnt a problem because of the fiberglassing, but as I start trying to clamp the canopy in place, the gap gets bigger and bigger.

In the rear, the plexi is about 2 inches away from the roll bar on either side, and when I try to sqeeze it together the rest of the canopy moves out of position. The front comes up and rearward mostly. Having alot of trouble keeping the canopy from moving backward. I also cant get my clamps into the frame in the rear they dont fit.

The canopy touches the roll bar on the top but not on the sides

Everytime I try to start clamping, everything moves off center and I need to start over.

I cant tell which trim I have made is correct. Sometimes I think ive cut to high, sometimes not enough.. ill center it all up again and now its the opposite. I cut the notches for the frame ribs, and now when its all centered again the notces arent in the right spot. Sometimes it looks like I wont have the edge distance in some places to put a rivet in to the frame, then 5 minutes later it looks like I need to cut another half inch off.

I feel like I need to trim more, but have no idea what is too much. I cant clamp it without it moving all over the place. When I do clamp it the front tip is floating a half inch in the air and has moved rearward. I cant squeeze the back of the canopy to the frame. I dont know what I am asking, I just know I am getting nowhere. Anything to share, anything at all? Im ready to start using this canopy for target practice.
 
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Hitting a moving target??

My reply may not answer you directly, but our experience with two RVs may help. Many of the assemblies travel until they are firmly secured so what we've done is establish (what we call) "registration". In other words, we create a fixture or affix the wayward (flexible) part to the airplane so it lines up the exact same way every single time we take it off and put it back.

For example, to get the 6A cowl to line up and not require 3 weeks (which the first RV project required), we mounted the engine and made a spinner out of wood the precise thickness the cowl needed to be away from the engine. We drilled the cowl so that every time it went on and off it came back to the exact same place. Same height, same distance, every single time it went on and off.

For the canopy (the 6A is a tip up), we made delrin blocks so the frame ended up in the same location every single time. It also took the same shape every time. Then the plexi was lowered onto the frame and the adjustments could be made gradually.

Unless the primary fixture (canopy frame) returns to the same location and goes back to the same shape, it's like trying to hit a moving target and will be very frustrating.

I hope this helps you but stick with it and ask questions whenever you need to. The number of people who fly airplanes is miniscule but the number who build and fly their own airplanes has got to be so tiny it's not measurable. Once your bird is flying, you'll look back at the grief and know it was worth it. 228 flying hours later, I still grin from ear to ear every time I climb out of my 9A.
 
canopy frame

Barry gave some good advice. Another thing I found is that you should not be afraid to bend the canopy frame. It most likely is not in the perfect position, and will obviously affect where the canopy sits.

Don't trim until you need to - it's hard to put the plastic back on. :)
 
Dont get to concerned. The aft part of the frame on the 8 usually needs to be bent. Its been a few years since I built my last 8 but I believe the manual has this issue in it. If I lived near I would be glad to help. Hopefully one of the local 8 builders will assist you.

Pat
 
I feel your pain

I struggled with my canopy too. I believe I make 70ish trim cuts to get it where I wanted - it was miserable and nerve-racking. If you can salvage the back part, you can order a flat wrap windshield from Jeff and Becky at Airplane Plastics in Tipp City, OH. They are a around $160ish and they look better than the stock one in my opinion.
 
Front windshield

I am putting a flat wrap windscreen on. Have made the big cut, and it's a good front windscreen. I just want to hold onto it until I know I have a good flat wrap install, then I don't mind parting with it.

Until then, if you have cut too much off the front and you don't mind waiting, you can have it (just pay shipping). Dave
 
I did the big cut one month ago and thought also that the gap of in front of windshield was too big ( 1 cm at the biggest), but in fact, after finishing the canopy, I glued windshield in place ans does not have any problem, including with molding. Finished today the entire canopy/ windshield
 
what did you guys use to hold the canopy in place while clamping it? Also, I cant get many clamps on the rear of the canopy, its too close to the fuselage. I guess i need to find different clamps.

What or did you guys clamp it down? When I start clamping front to back, the rear raises up.

How high were your notches? I thought I had them, but now i feel like i need to cut more. Thats how I got in trouble with the windshield.
 
Matt,
I used some small spring clamps, it is tight back there where the canopy is thickest. See pic below (somehow it got distorted when Matt D. changed the Kitlog picture properties).
Also, my builder log has most of the steps I used.
FP28062009A0000U.jpg



http://www.mykitlog.com/users/display_log.php?user=owens&project=236&category=4794&log=82640&row=163
 
that picture looks like its after you made the big cut. I need to figure out how to clamp down the rear before the big cut.

And do you have any tips for figuring out how much to trim off to get it clamped right for the big cut?

Are most people making the big cut right on the plane like the plans say? does it need to be fully clamped in place?
 
I built a support that would allow all of the cutting to be done away from the fuselage. The canopy is much easier to access this way. I used a butt-load of rubber-cushioned spring clamps to lock it down...maybe 30 or more of them.
 
Big cut

I did my big cut using a fixture as well. Also, I cut my intentionally long so I'd have more options with fitment since I wasn't using the front of the bubble for my windshield.
 
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