Slider - not sliding smoothly.

[flybye]

My sliding canopy doesn't move as cleanly as I'd like. The problem is that before the canopy is installed on the plane, the span of the rollers is about 1/4 in wider than the tracks on the fuselage. This means that once installed, the rollers are braced against the outside of the tracks. I'm considering adding a second roller to run along the outside of the track to keep the primary roller centered but thought to tap the experience of others before making modifications.

[PaulvS]

Builders in my group who have had similar issues with the canopy frame (it's not uncommon) have adjusted it by bending it either in or out. It can take a bit of pressure to widen or narrow it. And an adjustment in one location can affect another dimension.
Obviously this needs to be done before fitting the plexi.

[scottmillhouse]

The frame needs pulled in about an extra 1/2" to compensate for the Plexiglass pulling it out. If you can not cold bend use a little heat by torch and it will move where you want with proper application. I made a jig for proposed span and made it 1/2" smaller as predicted the canopy pulled it out with no side drag when attached.

[dreed]

I second what Scott said- you need to get it a little narrower so when you get the canopy on it'll spring out a little and slide smoothly.

Also, I do notice mine is a little stiffer in cold weather.

[wirejock]

If it's built, not much can be done without the possibility of cracking the plexi.
If you're building it, take measurements accross the tracks on the forward end and another of the aft top skin where the bow has to clear. Clamp the canopy to the bow and compare. Bend, clamp, measure, lather, rinse, repeat a thousand times till it matches the measurements fore and aft.

[Jpm757]

I used safety wire to hold the canopy frame inboard 1/2" while fitting the canopy.

[flybye]

The canopy was fitted to this frame by the SikaFlex method. Vans advises to bend the frame to a narrower width than the rails since the canopy tends to pull it apart. I followed this advice but the frame still splayed out until it was oversized and too tight.

I tried a process of heating the completed canopy that others have had success with. The rollers were pulled towards each other using a ratcheting strap until they were about three inches narrower than the width of the rails. I then covered the canopy in blankets as insulation. I placed a thermostatically controlled heater under the canopy, gradually increased the temperature to around 130F and baked it for a week. Once cooled and with the ratchet strap removed, this reduced the span by about 1/2 in, not quite enough to reach the desired result. The added drag when opening the canopy isn't huge but I'd really like to eliminate it.