After the 'Big Cut' . . .

Tip Up Canopy question
So... after successfully separating the front from the rear canopy, I have been trimming and re-trimming the leading edge of the front canopy exclusively in an attempt to make it lower, thus allowing the lower portions of the aft edge to line up with the marks on center of the roll bar. (the canopy was quite a bit higher than the roll bar before the big cut...after the big cut , the aft edge setttled lower , but now doesnt line up)
This had been a painfully slow process and I'm starting to question my methodology.
I'm I correct in NOT trimming the rear edge of the front canopy after making the big cut? Other than just smoothing the edges, I haven't touched it.

Trim to fit means you trim all edges, including the big cut edges to get it to fit.

There is no science to this, but make some alignment marks on tape, then sand down to the tape.

Disregard, I missed that it was a tipup

I have a tip up and had these same questions. I did not (will not) trim the back (big cut), precisely, until last. One minor caution. Trim along the sides as you trim the front. The reason is that the sides need to be pulled into the side rails in the end, and it will pucker the front up 3/8" at least. If you can make some clamps from some channel or a couple of angles that will fit under the side rails when the frame is down, it will help pull the sides snug, not tight against the rails. I wish I had taken the time to do this as it would have made the fitting less risky. Maybe 3-4 clamps per side. I will add a link if I can find it again. Yep, here it is: http://www.europa.com/~swayze/RV-7A/Finishing/20120420.html

BTW - My frame is ready to assemble and glass. I will wait until the front skin is riveted to do the glassing, and then, finally, fit the back of the plexi so it has a proper gap to the back light upon closing.

There is a lot of geometry to this fitting, so keep thinking about the big picture and don't allow focus on one area to short cut others.

Good luck - - stick with it, you will question yourself many times on this, 5 steps forward and 3 steps back. I fitted precisely, then had to do it over three times as it went off with further steps. Patience, and thought, is the recommendation !!!!

Thank you all for your replies

Clamps

Interestingly those clamps in the photo from Bruce's website were made by the second poster bruceh. I know because I have them now. They will be moving along as soon as I "sikaflex" my canopy.

sahrens said:

Interestingly those clamps in the photo from Bruce's website were made by the second poster bruceh. I know because I have them now. They will be moving along as soon as I "sikaflex" my canopy.

Click to expand...

Small world. The clamps are good for more than "sika" applications. They pull the sides of the plexi snug against side rails. This causes both pieces to flex as they comply. This changes the shape of each and alignment is impossible with out doing this. The rails can not be made to follow the fuse unless the plexi is attached. Waiting until the screws are installed is too late. One should be able to foresee this, but I did not and did not find comments about it. I looked everywhere.

You California guys have all the coolest tools!!

Bill, could you, or someone else, post a closer picture of those clamps? I can see them in the pics but I'm having trouble visualizing how they work. I see the channel and what appears to be a block of wood on one side and a screw on the other. What does the screw bear upon and what's on the end of the screw to protect what it bears upon?

Thanks

The canopy frame is L shaped, which adds to the challenge of clamping the canopy. The aluminum channel slides under the canopy frame to provide the 1/8" spacing. The wooden block is attached to the inside of the clamp and it spans the distance from the channel to the inside of the canopy frame. This allows for a square, flat surface for pressure on the inside.

On the outside is a bolt (the channel has been tapped) with a plastic boot over the end. Similar to the boots you can purchase for clecos. When you screw the bolt into the clamp the booted end applies pressure to the canopy. The boot protects the canopy.

Here is the only picture I have:

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sahrens said:

The canopy frame is L shaped, which adds to the challenge of clamping the canopy. The aluminum channel slides under the canopy frame to provide the 1/8" spacing. The wooden block is attached to the inside of the clamp and it spans the distance from the channel to the inside of the canopy frame. This allows for a square, flat surface for pressure on the inside.

On the outside is a bolt (the channel has been tapped) with a plastic boot over the end. Similar to the boots you can purchase for clecos. When you screw the bolt into the clamp the booted end applies pressure to the canopy. The boot protects the canopy.

Here is the only picture I have:

[/URL][/IMG]

Click to expand...

That's great, Scott, thanks. The pic plus your explanation helped.