lostpilot28

lostpilot28

Well Known Member
Is there an easy fix for a slider canopy that fits a "little too tight" on the slider tracks? After permenantly attaching my canopy to the frame I found that it pulls it outward about 3/8-inch which is enough to apply some friction on the rails. Simply stated, it doesn't slide freely.

I guess that could be a good thing while taxiing if you wanted it to stay partially open without holding it, but overall I think no resistance would be better. I don't really want to re-drill the holes for the tracks...so I'm hoping to hear that there's a quick fix or that others have this same "problem" and it's no big deal.
 
I don't believe there's a fix that doesn't put the canopy or the frame at great risk of cracking. I'm posting this negative reply so future searches might find this tidbit: Initially squeeze the slider front bow 3/8" narrower than the tracks, and the rear ~1/4" narrower at the pins before drilling to the plexi. (Your dimension, Sonny, is what I've observed thrice over). Don't relocate the tracks outboard because that will foul up side skirt fit.

This is another instance where the instructions lead builders astray. Van's properly cautions at the outset to not go tweeking the frame after the holes are drilled because there's a real good chance it will crack at a hole. Yes sir, spot on. Later the instructions contradict themselves by saying to squeeze the drilled frame to compensate for bow expansion due to the plexi springback. I really wish Van's would clean up some of these long-running, blatantly erroneous instructions.

John Siebold
Boise, ID
 
Can you oblong the screw holes on the tracks so they can slide in or out a little. Sounds like you don't need much movement, so a little on each side may do it.
Good luck.
 
You didn't say if the canopy was permanantly attached to the frame yet. If not, bend (narrow) that frame one more time. Otherwise, I'd vote for stretching the holes in the decks under the tracks.
Steve
 
About two months ago I posted a thread on this forum asking whether anyone had ever heard of heating the plexi in the sun while doing the initial fitting. I got no response, but lo and behold in the most recent RVator there is an article about someone doing exactly that. If the plexi is what is distorting the frame, letting heat up in the hot summer sun with a little extra preload might do the trick. Check the article out.

FWIW, after I drilled the canopy to the frame I found mine too tight as well, even though I initially squeezed the forward bow 1/2" narrower than necessary and the back slighly less. So, not wanting to live with a tight canopy the rest of my life, I took the canopy off and bent the frame a little bit more, even knowing the contradiction within and between Van's instructions and conventional wisdom. Surprisingly, my #30 holes still lined up perfectly, but the canopy now slides freely. I still haven't drilled the plexi up to 5/32, so there will be even more leeway once I do. I know other builders have done this successfully as well, but I don't know why somepeople seem to get away with it and others don't.

Also, be sure you are opening and closely the canopy from the centerline, either up at the latch handle or at the back center. If you try to open it from the sides, the frame (even with canopy on) will want to rack just enough to make it difficult to slide, making you think it doesn't slide well when it actually might.

Good luck. If all else fails, call Vans. I'm sure you're not the first person to have this happen.
 
Slider helpers

Hi Sonny,

Mine was a bit tight, too. Some suggestions:

  • Round the outside of the roller wheels - it helps cause less drag on the rounded outside of the tracks
  • Make a slider helper for each side - these are channel shaped pieces of UHMW material that keeps the rollers centered in the tracks - they straddle the the roller bracket and ride on the track

I made some and they work great.

sliderfixxq2.jpg


I shamelessly stole this idea from Alex Peterson - I'll try to get some pics for you tomorrow.
 
Hey guys, thanks for the ideas. To those who wanted to know, my canopy is permenantly Sikaflexed to the frame. I'm not TOO worried about it cracking if I try to bend it in a little, but as I did that this morning I heard a bit of creaking and I got scared! It may have been the tape holding the protective plastic on to the Plexi...either way, I stopped bending just in case.

Pete, I like the roller track idea...not sure where I'd get some, though. I may just try to round the outer edges of the wheels and grease them up. Any suggestions on how to round the edges of the wheels uniformly?

Just for the record, I did add a little Aeroshell #5 grease (that's all I had) and it did free it up a little bit. I'm definitely noticing a big difference when pulling from the center handle, but it's still quite draggy.
 
lostpilot28 said:
.....Any suggestions on how to round the edges of the wheels uniformly?.....
Click to expand...
Attach a nylon wheel to a mandrel made out of a screw or threaded rod etc. and attach the assembly to a drill motor. While spinning in the hand drill, hold the nylon wheel at an appropriate angle to a bench sander that is also turned on and bevel the edge to suit in mere seconds.
 
My slider was pretty tight at the initial fit. I too was concerned. However, a friend said don't worry about it, it will smooth out after a while. Sure enough, it did. Now I can pull the release tab, and it will roll back to the stops on its on.

No guarantees, but I would wait a while and see if it loosened up before I did a whole lot of adjustments right now.

FWIW, YMMV, and all the usual disclaimers.
Wes Hays
 
Assure that the slider block isn't binding. I had one that dimensionally passed easily over the guide, but pinched the rail when tipped fore or aft with movement of the frame. It was a bad combination of gap and angles easily relieved by opening the slot more.

Also, did you get the roller assemblies drilled absolutely parallel with the track?

John Siebold
Boise, ID
 
Thanks again, fellas...Wes, I'm leaning toward leaving it alone, as you said. But I'm going to check a couple of items that John pointed out, like the rear slide. I know it's a pretty tight fit and may be causing some friction.

The wheels are not yet drilled to the frame, but I'll pay particular attention to make sure they're straight.
 
Mine moved freely before I permanantly rivited the sideskirts on. My sideskirts fit pefectly and are quite draggy even with anti chafe tape on them. It has smoothed up a bit after opening it and closing it a bunch and I am happy with it. I would rather have it tight and sealed with a little drag than having any gaps between the skirt and fuselage. Don
 
Slider helpers

Sonny,

Here are some pics of what I did. Design credit to Alex Peterson.

sliderhelpers006ar9.jpg


sliderhelpers009jx0.jpg


sliderhelpers011yx9.jpg
 
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Now there's a good idea, Pete (and Alex). That just might solve some issues I'm having.

Is this a great resource for info, or what?!?
 
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