[justplanecrazy]

A big pre thanks for all your input. I am currently having a ball trying to bend the sliding canopy frame as per the instructions:

"The canopy frame side bows match the shape of the fuselage, but are inset 1/16"."

"The rear bows of the canopy frame closely match the contour of the F-7112 skin but are inset about 1/16"."

How critical is the 1/16" when it comes time to fit the side and rear skirts. I.e. how much tolerance can be manipulated into the skirts for variations in the slider frame.

Thus far I have read all the posts and websites but cant seem to find anyone that has referanced back any findings after completing the skirts.

Thanks for all your input.

 

[Lars]

The closer you get it, the happier you'll be.

That said, I had nearly 30 (not a typo) hours into mine, trying to make it fit, and didn't really get it right. My frame was pretty bad to begin with. The aft bow was quite asymmetrical. Had I known then what I know now, I would've requested a replacement.

As it turns out, I broke my canopy- nope, not from a rivet hole, from dropping a tool on it, very stupid. Because I'd used Sikaflex to bond the canopy in place, I was able to cut the canopy free to reuse the frame. I took the opportunity to improve the fit, but this time I had help from a couple of experienced guys, and we were able to make it fit better in about 45 minutes than I was able to accomplish solo in almost 30 hours.

I laid up a one-piece composite skirt, but the canopy to fuselage fit was good enough after round two that I'm confident I could've made the aluminum skirts fit well if I had gone that route.

 

[C-GRVT]

The tolerance is a function of what is necessary to make it work (and how close to perfect you want to get).
Understand the reason for the instruction for the 1/16" gap. If the frame is proud of the fuselage skins, when you add the thickness of the plexi the skirts will be too far out from the fuselage skins. so it will be difficult to get the close fit that you want. If you inset the frame too much at the rear, you will catch the skirts on the skins. That will affect the ability of the canopy to operate, so there is not much tolerance there, although the plexi can be shimmed as well if the frame fit is off.

The closer that you can get the frame to fit, the easier the rest will be. I can tell you that I was able to get the 1/16" measurement almost perfectly.
If you look a the FAQ for the canopy frame on Van's site (Scott McDaniel wrote it), you wil see also that the frame needs to be squeezed to account for the spreading force that the plexi will exert once installed. Another variable to the tolerance mix!.

If you use a fiberglass rear skirt, there is probably greater scope for some misfit of the frame at the rear. In short, I would get the frame as close as possible, and you can get it very close, to minimize fitting problems of the rest.
Bill Brooks
Ottawa, Canada
RV-6A finishing kit

 

[mikehoover]

Getting the 1/16" on each side of the canopy frame side rails wasn't as difficult as getting the aft bow to 1/16" below the aft top skin. I got close but a bit high, so I had to correct by forming the aft skirts. This took a lot of work. So the closer you are, the less trouble you will have when fitting the side and aft skirts. On the aft bow, I put it in place, marked where it needed to bend out, and where it needed to bend in. You have to anticipate what the bends will do the frame. A slight bend outward near the top of the aft bow will bring the whole side of the bow outward, so perhaps a required inward bend farther down might not require much. I put the frame on and took it off a couple (or few) dozen times. A tool that helped me greatly was a conduit bender. I would mark where the bends needed to be along the aft bow and bend them with the conduit bender. Didn't take much to exact a slight bend in a confined point. Worked for me.

Good luck!

 

[BruceP]

Roller Track width measurement

On Page 9-11, it talks about positioning the roller tracks once you've adjusted the frame shape to get the 1/16" inset. It goes on to state "This should position the tracks approximately 40 13/16" apart when measuring between the roller tack inboard vertical surfaces".

When I did this on my plane I measure a full 41 3/16". Now I'm nervous and stuck there. Anybody get similar measurements or am I doing something really wrong??? My longerons were bent nearly dead on the drawings between the F904 and F905 so my fuselage width does not appear to be over large.

I'm afraid to go any further with this kind of discrepancy to the plans and haven't worked on it for 2 solid weeks...

 

[Lars]

On Page 9-11, it talks about positioning the roller tracks once you've adjusted the frame shape to get the 1/16" inset. It goes on to state "This should position the tracks approximately 40 13/16" apart when measuring between the roller tack inboard vertical surfaces".

When I did this on my plane I measure a full 41 3/16". Now I'm nervous and stuck there. Anybody get similar measurements or am I doing something really wrong??? My longerons were bent nearly dead on the drawings between the F904 and F905 so my fuselage width does not appear to be over large.

I'm afraid to go any further with this kind of discrepancy to the plans and haven't worked on it for 2 solid weeks...

Have a look at this thread: http://www.vansairforce.com/community/showthread.php?t=27129

My fuselage (a quickbuild) is closer to yours than to the plans. Position the tracks such that the roll bar will be inset the correct 1/16", and make sure the tracks are parallel. The rest will take care of itself.

Also, the plans show how you may have to clearance the aft end of the tracks to clear the skirt. It shows how much you may have to remove. That wasn't enough in my case. But in the end, it all worked out, my canopy fits, the rollers roll smoothly, etc.

Oh yeah. Fitting the nuts to the #8 screws that retain the tracks is a pain. Someone posted a tip on making a strip with K1000-8 nutplates as an alternative. I took the advice. Much easier. You can pick up all but the most aft screw that way, and that one you can reach easily.