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  #1  
Old 05-27-2014, 08:30 PM
dbaflyer dbaflyer is offline
 
Join Date: Oct 2009
Location: Iowa USA
Posts: 196
Default Fitting canopy frame to the plexi-bubble

The fit is relatively good until I clamp the frame to the bubble. There is a substantial gap between the forward bow and the bubble after clamping. There is a gap on the right side by the tape before clamping, but thought that could be closed with shims. Here are some pictures before the clamps where added:

Right side - not clamped to the frame


Left side - not clamped to the frame


This is what happens after clamping the bubble to the frame:

Right side - clamped to frame


Left side - clamped to frame


This is looking at the center to get both sides at once


This does not look right to me. If it is normal it would not be easy to transfer a cut line along the front bow.

I'm at a loss at this darn canopy stuff. Nothing seems to fit right. I can accept that but need some wisdom on moving forward with what I have right now.

Thanks.
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  #2  
Old 05-28-2014, 08:37 AM
Sig600 Sig600 is offline
 
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Location: KRTS
Posts: 1,798
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It doesn't look like you've cut anything yet. What you have is normal. Try not to over think it too much. Once you start to trim it down the canopy will get much more pliable, especially after you split it. Don't worry about it, like the directions say, find where the canopy fits best fore and aft for now. For making the split it's all about where the "spine" of the canopy frame fits the best.

If you have split it, keep trimming. Then do final fit. Watch the measurements that the directions describe, the canopy will pull/bow out the frame. Mine was similar to yours but once you clamp it all together after trim, it pulls together.

Once it's trimmed, the canopy will be much easy to 'wrap' to the frame.
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Last edited by Sig600 : 05-28-2014 at 08:41 AM.
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  #3  
Old 05-28-2014, 08:58 AM
airguy's Avatar
airguy airguy is offline
 
Join Date: Oct 2006
Location: Garden City, Tx
Posts: 5,596
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Don't worry about that gap for now - you're just trying to find the correct point to do the first "big cut" at this stage. Once you've got the canopy cut and edges sanded (do this IMMEDIATELY, to keep it from cracking), then you can clamp all 4 edges and it will smooth out nicely.

There is quite a bit of flex in the canopy, and some flex in the frame - getting it all to fit "just right" the first time is a lottery ticket, and the directions from Vans just plain suck eggs on this. This was the single most frustrating part of the entire build for me.

Couple tips - don't do any cutting or drilling below 80 degrees. Don't cut or drill on any piece that is under any kind of bending stress, support it where needed to keep any stress from building up as you make the big cut. When you drill through the canopy, use only very light pressure, just barely have the bit in contact - you basically want it to melt its way through from friction rather than truly drilling through, and use the plexi bit (or take a standard bit and dull the **** out of it by trying to drill through a brick, then you'll be ok). When you cut the canopy, make sure it's in a position so that you can sand the edges smooth IMMEDIATELY, without moving or handling it - the cut will have thousands of stress risers on that edge and it's way too easy to crack a canopy by handling it before sanding a freshly cut edge. Cut it long, leave plenty material, sand it smooth and remeasure, then cut it again. Sneak up on it and you'll be OK (mostly, probably ).
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Last edited by airguy : 05-28-2014 at 09:04 AM.
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  #4  
Old 05-29-2014, 09:55 AM
fabricflyer fabricflyer is offline
 
Join Date: May 2011
Location: Tylertown, MS
Posts: 192
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I agree with you airguy, this is the single most frustrating part of the entire build. My slider frame bow does not match up with the bow in the roll bar. After taking some measurements, I found the frame is a 1/4" longer from the center down to the square tubing on one side than the other. If I cut this out it will make the bow match up to the roll bar. It is aggravating that at some places in the build, they give you a measurement down to a 32th when it wouldn't matter, then when they are building a frame on a jig they are off a 1/4". As many as they have built, you would think they would be more precise.
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  #5  
Old 05-29-2014, 12:58 PM
DeltaFox DeltaFox is offline
 
Join Date: May 2009
Location: chesapeake, va
Posts: 97
Default canopy frame

I feel your pain Denis. I'm in the exact same spot although I haven't drilled the hole for the handle yet. If the center bar is a great fit, the forward bow has about a 1/2" gap between it and the plexi. My best fit seems to leave about 1/4" gaps in the forward bow and the center bar. I've been told (and Ken at Vans confirmed) to get the best compromise, then when you make the big cut it will get a lot floppier. One can only hope. I'll let you know what happens.
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  #6  
Old 05-29-2014, 02:15 PM
dbaflyer dbaflyer is offline
 
Join Date: Oct 2009
Location: Iowa USA
Posts: 196
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I might get to the cut this weekend too. It is good to know that leaving some extra material hanging over the front bow does not affect the wind screen position and placement. Since you are taking the extra from the aft portion of the windscreen.

Thanks for all the info and good luck to all.
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  #7  
Old 06-03-2014, 05:43 PM
dbaflyer dbaflyer is offline
 
Join Date: Oct 2009
Location: Iowa USA
Posts: 196
Default Made the cut

Got the bubble cut into two pieces.



Fits everywhere but the aft section of the top spine. Largest gap is 7/32nds.

That seems like an awful big gap to shim. I wonder whether the frame could be bent to conform better?



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  #8  
Old 06-04-2014, 12:04 AM
Sig600 Sig600 is offline
 
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Are you going to rivet or sikaflex?
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  #9  
Old 06-04-2014, 07:03 AM
dbaflyer dbaflyer is offline
 
Join Date: Oct 2009
Location: Iowa USA
Posts: 196
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I plan to use the Van's book method, so rivets.
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  #10  
Old 06-04-2014, 10:19 AM
Sig600 Sig600 is offline
 
Join Date: Nov 2005
Location: KRTS
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Two thoughts:

If you rivet, those will be carrying much more load and more likely prone to crack with temp changes. Some guys have been successful in heating the tubing to bend it, but you'll have to repaint/powder coat the frame.

If you sikaflex it (the stuff has a tensile strength if 160 lb/sq in), you can fill that void and no one will be the wiser.

I sika'd my first canopy, and doing napkin math figured it would take move than 50k pounds of force to separate the canopy from frame. If you take your time with the stuff it comes out very nice and looks really good from the outside. I did a test piece with sika on a scrap piece of tube and some canopy trim scrap. The contact area was 1.5x1.7" and after it cured I could not break it apart no matter how hard I tried.
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