Bending F-631A Tip-up canopy roll frame flange to 92.5 degrees

Pmerems · #1 05-14-2006, 06:11 PM

I wanted to get some clarification about the proper angle for the F-631A canopy roll frame. The plans call out to bend the flanges to 92.5 degrees but it is a bit confusing from the photos in the manual. Please review the line and chose which one is correct (A or B).

Thanks.

Paul

Radomir · #2 05-14-2006, 06:40 PM

Paul, I'm days/weeks away from doing just that. Just read the manual -- it may be an important clue when they say that flanges come out at 88 deg. out of the factory. If that roughly looks like your drawing B, then A is the answer

scard · #3 05-14-2006, 09:31 PM

Just did this a few days ago. Used a protractor and all. I did (A) and things seem to be coming together just fine (relative to canopy building).

Radomir · #4 05-20-2006, 09:12 AM

So I started with one of the channels that was nearly perfectly flat out of the box... but after bending the flange, it got twisted badly... Not even sure how to fix it (un-twist) now to be flat again... dont' even know where to flute to get it straight again.. arghhhh..

PS.. Not exactly sure why this is done at all (especially what's significance of 92.5 degrees??)... And since I'll be glueing the canopy on, not even sure this is really necessary.

flybill7 · #5 02-14-2007, 07:55 PM

Like Radomir, my channels were perfectly flat out of the box, and the flange was 90 degrees. But when I had the canopy on the airframe, resting on the roll bar and canopy skin, and I pushed the channels up to touch the canopy, the channels did not lay flush against the canopy.

It sure looked to me like the top flange needed to be like diagram "A". So I did that, and like Radomir, my channels are now twisted pretty badly. Fluting didn't help.

Thoughts, suggestions?

... Bill

Loman · #6 07-15-2011, 10:02 AM

Sorry to drag up an old thread like this but how could an angle described as "92.5" degrees be an acute angle as shown in A? There are two surfaces in question here, the web and the flange, and the angle between them should be 92.5 degrees. To get 92.5 degrees out of A, you have to forget about the actual web and assume the instructions are referring to an imaginary plane extending the web in a straight line running past the flange. Not likely, in my view.

I don't have the plexi sitting on my frame yet but the drawing (48) seems to suggest that the bow meets the plexi at right angles.

Furthermore, my F-631-A channels were delivered with the outer flanges factory-set at precisely 92.5 degrees as shown in Paul's option B. I think perhaps Vans has raised their game within the last year because the forward channel on the main canopy weldment was also precisely square even though the instructions say they need filing.

I am hoping that some of you original contributors to this 2006 thread (among others) can jump back in to tell me how it actually worked out for you in the end.

rzbill · #7 07-15-2011, 10:28 AM

Dwg 48 is a side view.
You need a top view.
Stand in the cockpit and look down at the longerons and let us know if they are parallel at the canopy bow position. If yours are like mine, they are not and therefore the bow flanges need to be bent to an acute angle.

Loman · #8 07-15-2011, 01:42 PM

Quote:

Originally Posted by rzbill

Dwg 48 is a side view.
You need a top view.
Stand in the cockpit and look down at the longerons and let us know if they are parallel at the canopy bow position. If yours are like mine, they are not and therefore the bow flanges need to be bent to an acute angle.

Bill, you are spot on. I was thinking in only one plane.

Wouldn' it be nice to have just one more phrase in the build manual explaining that and maybe a reference to an angle of 87.5 degrees, which makes a whole lot more sense - to me at least.