Canopy frame versus roll bar.

[TASEsq]

Is this a normal fit of the canopy frame to the roll bar?

In the attached photos, the canopy frame is the white tape and the roll bar is the blue tape. On the sides the canopy frame is a fair bit wider than the roll bar, but at the top the canopy frame is shorter than the roll bar.

To the point that I think I would want some shims / washers under the screws up the top - for fear when I do up the screws and the canopy pulls down to the canopy frame it may crack - as it will be drilled sitting on the roll bar (with a gap between the canopy frame and the canopy itself).

Anyone else see this?

 

[HAL Pilot]

See ph 38-14 hyperlinks in the WIKI

 

[TASEsq]

See ph 38-14 hyperlinks in the WIKI

Thanks, I always read your great wiki before a chapter but there’s nothing I could see about this? (No links on 38-14, nor on 38-21 which is the page I’m on now).

 

[mc607]

Page 38-14, Section 4 ... gap?

Hey guys, on page 38-14, section 4, joining C-01405-R+L, did you have a small (3/32'ish) gap between these two pieces once everything was together before match drilling the Canopy Handle Assembly?

vansairforce.net

Read through the above post. I had similar issues with mine. I did purchase a second aft canopy frame and it did fit a bit better. You may have to shim the top, at least, or it could hit the roll bar, as suspected. When fitting mine I would put a piece of note pad paper in between and slowly close the canopy and pull the paper out to check for any contact. I would slowly latch it, a bit at a time and keep checking. Mine was not so tight that it wouldn’t release the paper, at the top, when fully closed, but it was below the aft window, so I shimmed it for looks and drag to some extent.
I used something like these https://www.aircraftspruce.ca/catalog/hapages/washer_nas1515h08l.php
to shim my canopy up at the top and my rear window out on the sides to get them to align. Very hard to see the washers once in place.

 

[HAL Pilot]

Page 38-14, Section 4 ... gap?

Hey guys, on page 38-14, section 4, joining C-01405-R+L, did you have a small (3/32'ish) gap between these two pieces once everything was together before match drilling the Canopy Handle Assembly?

vansairforce.net

 

[Reflex]

Is this a normal fit of the canopy frame to the roll bar?

In the attached photos, the canopy frame is the white tape and the roll bar is the blue tape. On the sides the canopy frame is a fair bit wider than the roll bar, but at the top the canopy frame is shorter than the roll bar.

To the point that I think I would want some shims / washers under the screws up the top - for fear when I do up the screws and the canopy pulls down to the canopy frame it may crack - as it will be drilled sitting on the roll bar (with a gap between the canopy frame and the canopy itself).

Anyone else see this?

Trent,

No, I don't think that's normal....at least it wasn't for me. I had a couple of spots where the rear window and the canopy didn't mate up perfectly so I scuffed 1/32 washers and painted them to match the roll bar and shimmed the rear widow in a couple of places. I did this just to make the glass mate up. The picture below isn't at as good of an angle as your picture, but my glass came out pretty close to flat....maybe even flat.

I'm trying to think what might have caused your issue and I'm not coming up with much.

 

[TASEsq]

The gaps at the side between the canopy frame and the roll bar, is the canopy frame is about 1/8” wider than the roll bar. At the top, the canopy frame is about 1/32 lower than the roll bar.

I trial fitted the canopy glass, and it seems the canopy frame being wider than the roll bars at the side, is by design. My canopy glass is flush with the window on the left, and about 1/16 wider on the right hand side. I should be able to slip some washers under the aft window at the right hand side to take this up.

At the top tho, I can’t see any solution other than using some shims / washers between the canopy glass and the canopy frame. If I leave it as is and tighten the screws to pull the canopy glass down to the frame, will result in the glass being preloaded against the roll bar - which can’t be good.

I’ve asked support anyway - will see if they have a different approach.

 

[Reflex]

Trent,

I think you have it figured out. Yes, the canopy frame is larger by design than the roll bar. I too had a question about this issue/design. Van's tech agreed that it can be confusing. Below is a nice cad drawing they e-mail to me quite some time ago.

Regarding the spacers on the rear window, I don't think you have much choice. While I didn't have to go to 1/16", as per my post above, I did use spacers at various points on the rear widow to make what I would call a "proper fit". I painted them to match the roll bar/interior so you have to look REALLY hard to see them.

Hope the picture below helps.

 

[mc607]

At the top tho, I can’t see any solution other than using some shims / washers between the canopy glass and the canopy frame

That’s what I did and it worked out fine. You may have to install the washers/shims as you go. I didn’t have to but I used a piece of paper to gauge the gap. I could always pull it out of the gap, so I didn’t add the washers until complete to fine tune the profile between the canopy and window. The nylon washers are harder to see than what shows in the picture because of the countersink shadow. Not perfect but, as someone said on here, “perfection is the enemy of excellence”.

Note that because of the curvature of the glass and the frame that everything is likely to change once you snug up the screws.

I found this little drill jig I made to be very helpful to keep the drill bit and then the tap, square to surface

 

[TASEsq]

This is what I got back from support. Given that the thickness will change I was thinking washers would be a lot easier.

“Yes, you will need to do some shining. This is acceptable, however, the use of shim strips is better than using washers as is provides more contact area for the canopy reducing the chances of cracking.”

Here is a photo of the drill guide I used for the back window.

 

[mc607]

As there seems to be a bit of interest in this topic I thought I’d throw out some random items on this section.
It is quite important to keep the drilled holes square to surface

I used cedar shims to push the window aft. Helps to keep it snug to alum skins.

Did this for sanding block

It is very important to keep the window/canopy warm while working on it.
Highly recommend these tapered reamers for drilling window/canopy

Made this little collar (mini c frame) out of brass round stock. Used it for the one annoying dimple above the roll bar brace.

 

[TASEsq]

Nice tool making. Love a good shop made too. I went bush mechanic with my tool to dimple that hole.

 

[TASEsq]

Update:
I drilled the canopy today. Now I’ve got it cleco’d on (with #40 clecos), I used a bit of paper and tried to slip it between the canopy and the aft canopy frame. In some places it slipped in - but in most it didn’t.

I added some tape to a 1/64” thick shim to if there was anywhere which needed shimming and for the most part, I couldn’t get it to slide in at all. In a couple of places I could slide it in between the clecos but it wouldn’t slide in at the cleco locations - so the gap is negligible I think.

At this stage I don’t think I will shim the canopy as it lines up almost perfectly with the back window - on one side, I’ll need to shim the back window out a little bit that’s it.

 

[jcbarker]

Trent,

I think you have it figured out. Yes, the canopy frame is larger by design than the roll bar. I too had a question about this issue/design. Van's tech agreed that it can be confusing. Below is a nice cad drawing they e-mail to me quite some time ago.

Regarding the spacers on the rear window, I don't think you have much choice. While I didn't have to go to 1/16", as per my post above, I did use spacers at various points on the rear widow to make what I would call a "proper fit". I painted them to match the roll bar/interior so you have to look REALLY hard to see them.

Hope the picture below helps.

View attachment 73836

How did you get Van's to share their SolidWorks file of that assembly? I've tried several times and it's always been a hard NO.

 

[Reflex]

How did you get Van's to share their SolidWorks file of that assembly? I've tried several times and it's always been a hard NO.

John,

I'm pretty thick, many would say that I'm even dense. A picture worth 1000 words and I believe Tech got tired of trying explain/justify what I perceived as an issue.

Note: They didn't supply the file, only a .PDF of what you see above.

 

[Reflex]

Update:
I drilled the canopy today. Now I’ve got it cleco’d on (with #40 clecos), I used a bit of paper and tried to slip it between the canopy and the aft canopy frame. In some places it slipped in - but in most it didn’t.

I added some tape to a 1/64” thick shim to if there was anywhere which needed shimming and for the most part, I couldn’t get it to slide in at all. In a couple of places I could slide it in between the clecos but it wouldn’t slide in at the cleco locations - so the gap is negligible I think.

At this stage I don’t think I will shim the canopy as it lines up almost perfectly with the back window - on one side, I’ll need to shim the back window out a little bit that’s it.

Looks nice Trent. If the builder has to get it closer than that....we're all in trouble.

 

[jcbarker]

John,

I'm pretty thick, many would say that I'm even dense. A picture worth 1000 words and I believe Tech got tired of trying explain/justify what I perceived as an issue.

Note: They didn't supply the file, only a .PDF of what you see above.

Ahh, only a pdf. That explains it.