canopy bending

[trackdom]

hi,

I am cutting the canopy . But I am rather astonished by the gap between the canopy and the frame , at the rear part it is 2 inches at the maximum, and I have to apply a lot of load to touch the frame... Is it normal? It seems to me I have correctly positionned the canopy .

thanks for your help

[GJHeck]

If you haven't cut yet call me. 810 499-4616
Greg

[trackdom]

Originally Posted by GJHeck

If you haven't cut yet call me. 810 499-4616
Greg

I think it would be easier to communicate by mail than by phone
thanks

[rscooter]

I'm in the same position except I've already cut mine and I guess I'm going to have to live with it now? I don't know what to do. My bow is now 2 inches up from the slide bar.
Scott

[Allan Stern]

All I can say is "do not put a lot of pressure" on the canopy to bring it down into contact with the rear of the frame! You will be setting yourself up for a crack. I know. I think you are supposed to fit the canopy frame into the upside down canopy and adjust it so it touches the frame along most of it with very little pressure being used to hold it down.

I had a couple inches and I put a lot of clamps along that edge to pull the back of the canopy down to fit the frame. thought I would intall a pull rivet through the plastic to the frame and it cracked. I salvaged the canopy by stop drilling the crack (4 inches) and painted over it. Did not want to pay for a new one and decided I would live with that crack.

[trackdom]

Originally Posted by Allan Stern

All I can say is "do not put a lot of pressure" on the canopy to bring it down into contact with the rear of the frame! You will be setting yourself up for a crack. I know. I think you are supposed to fit the canopy frame into the upside down canopy and adjust it so it touches the frame along most of it with very little pressure being used to hold it down.

I had a couple inches and I put a lot of clamps along that edge to pull the back of the canopy down to fit the frame. thought I would intall a pull rivet through the plastic to the frame and it cracked. I salvaged the canopy by stop drilling the crack (4 inches) and painted over it. Did not want to pay for a new one and decided I would live with that crack.

I tried to put the frame a little upper to be closer to the canopy but I am not satisfied of it. I didn't cut the canopy in two parts yet, I hesitate a lot and don't know what to do... sorry for your crack!

[trackdom]

Originally Posted by rscooter

I'm in the same position except I've already cut mine and I guess I'm going to have to live with it now? I don't know what to do. My bow is now 2 inches up from the slide bar.
Scott

I think it's not easy at all to find the right position of the canopy relative to the frame and fuselage...
can't you put your canopy down to touch the slide bar?

[rscooter]

I keep trimming my canopy front and back than sides till it touched the top tube. Watched the trim lines on the front and back till it was the correct height. Canopy touched rear frame, had clamps all around and sat proper on front of plane per destruction manual on rear. I made the "big cut" not that big of a deal ( I used one of the reciprocating 1/2 degree saws from sears) and than I fitted canopy with clamps and drilled to frame. By the time I was able to pull in the sides I had to pull the bow of the frame up and put temporary rivets into it. It now has 1 5/16 clearance to the slide rail not the 5/8 to 3/4. I don't know what happened but no cracks as of yet? Hopefully not anytime soon. It seems that I'm going to have to compensate on the skirts since the scribe line on the top is a little low. Been a lurker on here for awhile and have just started to post. Thank you to all of you for your help so far by hearing your stories and logs. Will pay dues as soon as I can figure this thing out! Any advice or criticism is appreciative. I would put a picture on here but I'm kind of dumb.
Scott
RV8A
emp done
slow build wings done
QB fuselage done
Superior XP IO360 installed
Cowl installed
Dynon Skyview purchased nothing installed
80% done 100% still to go

[GJHeck]

Sorry for not getting back so soon. If you haven't cut the canopy yet...try theses steps.

1. make sure your frame is bent to line up the way you want compared to the airframe.

2. Now take your frame off the airplane and fit into the canopy while the canopy is upside down on the floor. Find the best fit inside your canopy.

3. After the frame is in the best fit position in the canopy mark lines along the frame where the frame touches the canopy on the plastic film covering the canopy. THis will help determine where the best fit is and where you can cut.

Notes:
-you won't want to cut your final cuts until the frame and canopy is on the airplane.

- if this doesn't work (canopy frame lining up properly inside the canopy during step 2) and still doesn't fit properly you'll have to contact Van's or the canopy manufacture to see if you can heat and bend.....I don't know about that or have them replace your canopy.

THis worked for my -6 model and probably will help you on your - 8 model

The more info you have the better your project will be. If I just tackled the job I would have been finished a long time ago

If your close to Paris let me know I get there often.

[jthocker]

Here's what I do. Cut the canopy from the base, make centerline marks on the front deck, windscreen bar, canopy front frame bow and aft frame bow, along with corresponding marks on the canopy. Trim to the line already marked on the canopy, keep trimming the front until the canopy comes down onto the frame at the windscreen. Trim the sides enough to get a couple of clamps on the sides, don't worry about the rear yet. Tape the front of the canopy to the front deck and put one clamp at the very aft. MAKE THE BIG CUT! Now set the windscreen aside, and remove the frame and put it on the bench. Put the canopy back on the frame and put one clamp at the front bow at the top center, then begin clamping from the REAR and work your way forward. This relieves all the pressure you guys are getting by allowing the canopy bottom forward edge to "grow" forward of canopy front bow. I just re-trim this edge. The fiberglass "targa" strip will cover any gap later. I have found this method then allows the pink canopy skins to fit almost perfectly.

A tip for the skins- Drill and cleco the skins to the frame except for the tails. Then get a helper to pull the tails around the aft end of the canopy while also exerting some forward/upward pressure on the "tail". This pressure causes the skin to "suck" into the fuselage just after the rear seat bulkhead. Drill the "blind" holes while your helper keeps the pressure on. The skins overlap and will require retrimming of the "notch" for the rail, and then will have to be spliced or joined per builder choice.