Canopy Frame Trials

[jpharrell]

I am fitting the dreaded canopy frame onto the fuselage. The good news is I have been able to get the F-702 canopy frame skin to butt up to the F-771 skin but the bad news is I find that the F-702 skin bulges out beyond the side skins. The bulge is about 4-5 inches wide and sticks out about 1/8 inch on the right side and .100 inch on the left side of the fuselage. Has anyone else had this problem and is there a solution to this?

 

[bruceh]

I had the same sorts of issues. You can slightly bend this skin to match the side, but just be aware that everything on the frame changes every time you anything.
I would wait until you are all riveted, and the internal stiffener is installed.

 

[az_gila]

You could bend the frame slightly so that the error is inwards instead of out wards. Then add thin shims at the time of final riveting.

It's always easier to add shims, even if you have to remove and re-rivet than to shave off aluminum...

Note that things will change, especially when you add the lift struts.

 

[jpharrell]

How to bend the canopy frame?

The forward channels of the canopy frame are pretty beefy. If any one has bent these to fine tune the shape, how did you do it?

 

[rcarson]

Canopy Frame

I did bend the frame to fit on both sides and it is very heavy and difficult to bend. You will find that it slightly buckles the frame and it is only noticable untill you install the stiffner kit which will cover up the bend marks. It really didn't make it more difficult to fit however I think the trick is to make sure the bend is in the first 4" from the bottom of both sides of the canopy frame. If I can figure out how to do it I will post a picture. Otherwise good luck.

 

[agirard7a]

Same problem

Wait. Did you take a picture of my canopy?

Trying to solve this problem I tried 3 different
Fixes. 1. I drilled out the riverts one side of the splice plate that joins the weldment, and changed the angle a bit downward. This helped.
2. I tried crimping the weldment with multiple crimps
In the area where it has a radius.
3. Sanded/ filed the weldment below the skin in that area.
And yes bent the skin. Still not 100% fair.

I am in the same process. Just finished the canopy frame
And made the big cut. Plan on glueing with Sikaflex.
The stories I have heard of cracked canopies, I see no need
To drill any holes in the front canopy.

I offset the side rails inward by using 1/8" shims
In order to have a 1/8" min. Glue joint. Worked great!

 

[jjconstant]

After having been through canopy purgatory myself, I agree that everything changes every time you put things on and pull them off, but especially when you try to marry the plexi to the frame. On mine I made the frame fit as well as I could, only to find out that the plexi pulled it outwards. I had to redo/undo much of the anal retentive fitting because it became clear that this was a "negotiation" between the frame and the plexi and the final fit was a result of long and arduous discussions between the two materials.

I would try and leave as much as possible in the temporary stage until you can see how the two materials will interact with each other and affect the final fit. Although the multiple builders might have some secret process where you can nail down certain things and then adjust the fit with a special customized sledgehammer Mine was in the form of a shrinker/stretcher tool.

All Best

Jeremy Constant

 

[BSwayze]

John,
Have you riveted the canopy frame together yet? There are a lot of little adjustments and movements you can make before final riveting, to get it to fit better. Even then, as others have said, everything can change. I took a ratcheting tie-down strap to my frame, to pull it together a bit. I'm right at the point of glueing the plexi on with Sikaflex, and it still doesn't fit perfect, but I'm pretty close.