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Slider Canopy Frame Fitting

rapid_ascent

Well Known Member
I'm in the process of fitting my canopy frame and having some issues. I managed to get the front bow sitting pretty well in reference to the roll bar. I had to cut about 1/4" off of the bottoms of the forward bow on each side.

I then started trying to get the side bows to fit 1/16" inboard from the side skins. On one side it seems very close. On the other side there is slightly too much bend in the side bow. I tried clamping it against a stout piece of hardwood to flatten the curvature. As soon as I un-clamped it and checked it is sprang right back in the same location. This side isn't off a ton but may 1/16". Suggestions on how to take some of the bend out?

The second problem I have is that the center of the rear bow is up too high. I'm not sure if I created this problem or if the canopy frame had the problem initially. Based upon the instructions I was more concerned about the overall width of the rear bow. I now realize that is the wrong way to work on the fitting. FYI, its more about getting each side of the rear bow to have the correct curvature. I think I know how to work on getting the curvature correct for the rear bow. What I'm not sure about is how to get the center of the rear bow lowered as much as I need. My side bows are 2-5/8" off the aft canopy decks on both sides when the side bow are level to the canopy decks. To get the center of the rear bow in the correct position it seems like I need to be around 2-3/8" which violates the 1/8" difference rule by quite a bit. It almost seems like I need to bend the center frame piece so that the center of the rear bow is lower. I'm not even sure that is possible. Any suggestions on this one?

I know this is normally a frustration part of the build but Saturday is was defeated on this frame fitting. Sunday I didn't even want to look at the plane. That never happens for me. Well it's been a couple of days and I've recovered but the canopy frame still need some man handling.
 
I’m working on the same slider predicament here, I got my slider to about were you are and resorted to fitting the plexiglass , one side fits perfectly at the back but I still have to get the other side bent in at the bottom and I may just end up shimming the top up to meet the turtle deck skin,, it is a frustrating undertaking but stay at it , a good fitting slider frame will save you a lot of frustration down the road , this is my second Slider & my first one need stripped by the time I got it to fit on my 6 !
 
This is basically how I did it a long time ago. Pretend that instead of resting dummy items on a sheet of cardboard, you screwed wood blocks to a tabletop. And instead of bending a piece of aluminum brake line, you used the same fixture to tweak your canopy frame.

You can get a lot of force on something this way if you orient the frame correctly. Make numerous small tweaks, not big ones.
 

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Canopy

If you get the rear bow to match the top skin, the top should fall into place. Workbthe shape first.
I'm not sure why they call out a dimension for the side bows. I didn't worry much about it but I fabricated a one piece skirt.
Don't cut those forward tubes anymore. Final trim is best done after the canopy is done and even after the windshield is attached. Then you can get the two very close.
Two dimensions are suoer important.
1. Width of the tracks and width of the bow at the rollers. You want the rollers to land in the middle of the tracks and bith tracks parallel ti each other. Obviously the bow dimensions change after the canopy is attached so measure often.
2. Width of the bow aft. If it's too narrow, it will hit the skin. Too wide is not great either but it can be disguised with the skirt.
 
A couple of years ago I wanted to replace the sliding canopy on the RV6 that I own. At Oshkosh, I inquired with Vans if they still made the RV-6 slider frame. The person said NO. I asked if the RV-7 canopy frame would fit an RV-6, and he said NO...... but then it doesn’t fit the RV-7 either.

I bought the RV-7 sliding canopy kit and got to work. It did fit much better than the original RV-6 canopy did but was still a lot of work.
 
This won't make you feel better maybe, but on my first one I worked on it for a month.
The second one I did it took me two days.

Hang in there, you will get it done. Walk away for a day then go back to it.
 
RV-7 slider Canopy Frame

I’m just going to throw this out there. I actually snapped my first frame trying to get it perfect, it eventually gave way at the aft of the spine. It was so close too.

I had bent it so much that it looked notchy, no real curve any more. After exploring options I put it down to experience and ordered a new one. I’ve just put it on out the box and it’s pretty good as is, a little wide at the back (by 1/16 on both sides) but the aft radius is perfect so don’t want to upset that. It’s completely symmetrical so I’m thinking of trimming the front posts (not all the way) and calling it a day. Am I completely out to lunch?

Ben

RV-7 slider
Lincolnshire, UK
 
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This was my experience. I worked on it flexing it around off and on for two weeks. Every time I got one area right it would bulge out somewhere else. I have done a lot of 4130 welding in my life so I cut it bent it to shape and welded it back together, saw, bend, and weld. Had it done in an hour. Do not try this unless you know what you are doing.
 
Canopy weldment

I’m just going to throw this out there. I actually snapped my first frame trying to get it perfect, it eventually gave way at the aft of the spine. It was so close too.

I had bent it so much that it looked notchy, no real curve any more. After exploring options I put it down to experience and ordered a new one. I’ve just put it on out the box and it’s pretty good as is, a little wide at the back (by 1/16 on both sides) but the aft radius is perfect so don’t want to upset that. It’s completely symmetrical so I’m thinking of trimming the front posts (not all the way) and calling it a day. Am I completely out to lunch?

Ben

RV-7 slider
Lincolnshire, UK

If its that close, leave it alone. Fiberglass skirt will hide any misfit.
BTW, don't make the final adjustment cut to the forward bow feet till the canopy is attached and the windshield done. It's easy to trim those feet but imossible to make them longer.
 
When I nested the frame to the canopy, the gap deviations went from almost 0 to 3/16". My canopy was attached to the frame using Sika and one would never know that the canopy did not match the frame exactly. I too used a base layer of fiberglass then layers of carbon fiber for my skirting. It turned our really nice. It is much more forgiving that aluminum to hide the not so perfect fitment.
 
I am also going through this frustrating build experience on my RV6 build. I built my first home built airplane, an RV6, more than 20 years ago, and spent at least 40 hours trying to make the slider frame fit. Never got there, but hid the poor fitting frame with skirting. I am now almost 40 hours into this “new” frame and it is just as frustrating as it was 20+ years ago. I think I’ll regret not reading this post a couple days ago. I trimmed .1” off the bottoms of the forward bar feet to bring the center down. Now it’s level with the windshield at the center, but below as it curves down to the sides. I should have listened to Larry. My rear bow is now too low relative to the fuse turtle deck skins. Raising it up would involve unbending the curved part of the rear slider channel. I already drilled it in place a month ago when it fit correctly there.
Like the OP, I really don’t even want to go to the airport to work on it, it’s got me so peed off….
 
Skirt

I am also going through this frustrating build experience on my RV6 build. I built my first home built airplane, an RV6, more than 20 years ago, and spent at least 40 hours trying to make the slider frame fit. Never got there, but hid the poor fitting frame with skirting. I am now almost 40 hours into this “new” frame and it is just as frustrating as it was 20+ years ago. I think I’ll regret not reading this post a couple days ago. I trimmed .1” off the bottoms of the forward bar feet to bring the center down. Now it’s level with the windshield at the center, but below as it curves down to the sides. I should have listened to Larry. My rear bow is now too low relative to the fuse turtle deck skins. Raising it up would involve unbending the curved part of the rear slider channel. I already drilled it in place a month ago when it fit correctly there.
Like the OP, I really don’t even want to go to the airport to work on it, it’s got me so peed off….

Fiberglass windshield trim and canopy skirt. No one will ever see. You should have seen mine before. Lots of after photos on my blog or read my articles in Kitplanes , Oct 2021 (sorry about the shameless self promoting).
 
Larry,
I did read your article (part 1) and some parts of it are unclear to me. It sounds like you used the aluminum skirt brace (C-691) and the inside skirt piece (C-759) in the final assembly, and that the fiberglass skirt will be riveted to those two aluminum parts and the canopy frame. Does the canopy still get sandwiched between the C-759 and the fiberglass outer skirt with #6 screws? It seems like there would be some concern about pop rivets and screws pulling through the fiberglass. I like the idea of the fiberglass skirt and wish there was a video showing how it all actually works. Also - the windshield is designed to use fiberglass skirting and forward transition, but why did you make it to pop off before gluing it back down? Couldn’t you just do the layup right on the plexi and forward boot cowl skin? Same with the top roll bar layers?

Thanks. Wish I knew what you know about this.
 
Canopy skirt

Larry,
I did read your article (part 1) and some parts of it are unclear to me. It sounds like you used the aluminum skirt brace (C-691) and the inside skirt piece (C-759) in the final assembly, and that the fiberglass skirt will be riveted to those two aluminum parts and the canopy frame. Does the canopy still get sandwiched between the C-759 and the fiberglass outer skirt with #6 screws? It seems like there would be some concern about pop rivets and screws pulling through the fiberglass. I like the idea of the fiberglass skirt and wish there was a video showing how it all actually works. Also - the windshield is designed to use fiberglass skirting and forward transition, but why did you make it to pop off before gluing it back down? Couldn’t you just do the layup right on the plexi and forward boot cowl skin? Same with the top roll bar layers?

Thanks. Wish I knew what you know about this.

Sorry. The article was more about how to lay up the skirt and less about how to assemble. Here goes...
Before bonding the canopy, fabricate one C-660 Aluminum skirt. Just the middle row of holes. Drill the holes in the weldment per plan using the aluminum skirt. Just use it for both sides. Ignore the top row of holes through the plexi and C-759. Drill the holes inside for the C-791 Canopy Skirt Braces as well.
The plexi is bonded (sandwiched) between C-759 Inside Canopy Skirt & C-660 Canopy Skirt just like it's shown in the photo, except there's no holes in the plexi and no fasteners in the skirt.
Rivet C-759 using every other hole. Leave the others open.
Bond the canopy using the C-759 per plan but no fasteners in the plexi. Sika will hold it along C-759.
Layup the skirt marking open holes as you go. Match drill the open holes left from C-759. Cleko C-791 in place. Cleko the skirt to the previously drilled holes. Climb inside and close the canopy. Using a helper outside to hold the skirt against the fuse, push the tabs on C-759 against the skirt, drill and have the helper cleko. Climb out. Now you have two rows of holes.
Bond the skirt in place using clekos instead of fasteners. Cure.
Remove the clekos, fill the holes, prep & paint.
Not quite that simple but that covers the main points.
I know some don't like bonding with Sika, but I tried several test samples with the materials and every one ripped fiberglass layers apart. Plexi broke in pieces. Aluminum bent. Sika never once failed. That said, please do your own tests and research.

As far as the windshield trim, I don't like sanding on my airplane. Too easy to hit something. Very difficult to remove an epoxied trim mistake. I was able to comlletely finish the trim off the airplane. If necessary, the trim can be removed and windshield replaced just like an auto.
20210915_190853.jpg
 
Thanks Larry. That makes sense now that I look at it with your explanation in mind, and seems way easier than what I had envisioned. I didn’t know Sika would work in a thin layer along the canopy frame. I’m assuming you also use the Sika to bond the completed windshield fairing back on. I also like the idea of sanding that fairing off the airplane.

I’ve used West Systems structural adhesive called ProSet to bond my canopy on my RV8 showplaces fastback kit several years ago. I called the Gougeon Brothers (West Systems) in Michigan to ask advice before doing this. They said that Spaceship One was entirely bonded together with this stuff. It is a wide temperature tolerant thickened epoxy, very similar to G-Flex - available at Lowe’s/Home Depot, etc. It can wet out cloth and is completely compatible with other West Systems epoxies. It has about a 4 hour pot life at 72* F, which was very helpful when bonding the entire RV8 FB bubble to the fiberglass/epoxy frame.

Now if I can just get that slider frame a little bit closer…….
 
My current 7A was purchased as an abandoned project. Canopy frame was drilled but frame was never fitted. It was so far off that a clecoed canopy was locked in place and would not slide. The front edges were about 1/2 too far outside. I could not bend or it would break so I made a jig and used heat and a hydraulic jack to apply an upward force when heating to pull the sides in. Worked great. That plus shims and a combination of riveting and bonding with the fabrication of a carbon/fiberglass rear skirt worked perfectly. A propane torch will not do it but a Mapp worked great. Just took about 6 heat cycles in about a half an hour.
 
Twisted slider frame

Just starting on the sliding canopy frame (on a 6A, I think that it is the same as the other slider models). The frame is twisted off centre by about 3/8" so that when the front bow is parallel to the roll bar the rear guide block does not line up with the aft T track. See attached pics. I'm going to try straightening it using the method depicted in the Vans support bulletin.
 

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Canopy

Just starting on the sliding canopy frame (on a 6A, I think that it is the same as the other slider models). The frame is twisted off centre by about 3/8" so that when the front bow is parallel to the roll bar the rear guide block does not line up with the aft T track. See attached pics. I'm going to try straightening it using the method depicted in the Vans support bulletin.

Before you twist, take some messurements and make sure the side bars are higher at the aft end on one side and lower on the other. It looks to me like the aft is slightly starboard of center. That's a totally different bend. I would clamp it forward tube down and pull the aft end toward the port side.
 
Just me

Hi all just want to jump in here.
This is what i am planning on doing. Any comments?
 

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As for bending the frame, here's another possibility. You can quantitatively bend by torquing with the cargo strap, mark how far you torqued, release and see where it moved to. A laser helps.

The front bow is attached to the bench top with electrical conduit U clamps.

You can use multiple straps from any angle.
 

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Hi all just want to jump in here.
This is what i am planning on doing. Any comments?

I screwed my canopy in, with no issues on the sides after 15 years/1380 hrs. HOWEVER, the canopy cracked 13 years ago and I later found out some builders cut it right down the middle and glued the two halves to the frame's center tube; the seam is then hidden under the C-653 cover strip. It seems to me to be brilliant move, relieving the (inevitable) torsion in the canopy assembly that can lead to a big crack. Are you planning to do that?
 
As for bending the frame, here's another possibility. You can quantitatively bend by torquing with the cargo strap, mark how far you torqued, release and see where it moved to. A laser helps.

The front bow is attached to the bench top with electrical conduit U clamps.

You can use multiple straps from any angle.

I don't remember having to correct that kind of anomaly, but I do vividly remember that getting the canopy to fit the frame and having to make the skirts out of fiberglass because the whole thing didn't fit right caused me to seriously consider abandoning the project - or to roll it off a cliff with me in it!
 
We dont need no education -Pink Floyd

I don't remember having to correct that kind of anomaly, but I do vividly remember that getting the canopy to fit the frame and having to make the skirts out of fiberglass because the whole thing didn't fit right caused me to seriously consider abandoning the project - or to roll it off a cliff with me in it!

Dont get me started. I am working the windscreen. Part of the problem, and maybe the solution, is it all is like a wet noodle.
 
… cut it right down the middle and glued the two halves to the frame's center tube; the seam is then hidden under the C-653 cover strip. It seems to me to be brilliant move, relieving the (inevitable) torsion in the canopy assembly that can lead to a big crack. Are you planning to do that?

No there is no center strip on mine. The canopy is sima to the top frame a d smooth on the outside. That must be a bear to fit; seems to many pieces.
 
Before you twist, take some messurements and make sure the side bars are higher at the aft end on one side and lower on the other. It looks to me like the aft is slightly starboard of center. That's a totally different bend. I would clamp it forward tube down and pull the aft end toward the port side.

Thanks Larry, the four bottom corners of the frame i.e. the forward tube ends where the rollers fit at and the rear locking pins are all in the same plane because it sits evenly on a flat surface. I took diagonal measurements between each forward roller bracket and the top centre of the rear bow and there was a difference of about 10mm.

I clamped the forward bow between two long 2x6 boards on the floor and then stood on it and pulled it over with all my might until the measurements matched. It fits better now, however the side tube alignment over the longerons at the rear is not the same LHS versus RHS so there is more work to be done.

Separately, I'm now not sure if I attached the sliding tracks in the correct position. I set the distance apart based on centering the rollers in the tracks and making the tracks parallel ("make the parts fit the parts"). But if the front bow was not already the correct width (whatever that is?) then the tracks will be in the wrong position. The only indication in the drawings of what is the intended track position is section F-F on dwg SC-1B, which shows the track as being flush with the sides at the rear.

This appears to be a much bigger job than I initially anticipated and part of the challenge is that I don't know what it is supposed to look like when it is "good".
 
Tracks

...snip...
Separately, I'm now not sure if I attached the sliding tracks in the correct position. I set the distance apart based on centering the rollers in the tracks and making the tracks parallel ("make the parts fit the parts"). But if the front bow was not already the correct width (whatever that is?) then the tracks will be in the wrong position. The only indication in the drawings of what is the intended track position is section F-F on dwg SC-1B, which shows the track as being flush with the sides at the rear.

This appears to be a much bigger job than I initially anticipated and part of the challenge is that I don't know what it is supposed to look like when it is "good".

The front bow dimension (width) is confusing but there are some clues. There are some dimensions on the plans to get the frame located so the skirt falls flush. If you do some math, you can figure out where the center of the roller will land and that becomes the center of the track.

Watch the cut on the legs. Better to leave a little than come up short.

You are correct. The tracks need to be as parallel as possible or the rollers will bind. In fact, the drawing shows a portion of the tracks cut away at the aft end.

Yes, its a bit like herding feral cats! :D
 
Fixing the beast

It's no wonder that many builders resort to Sikaflex and fibreglass, and that the RV-14 is tip-up only. The combination of Vans design, quality control and instructions for the slider is absolutely shameful (but I still love dreaming about flying it one day).

Anyway, today King Kong turned up and helped to eliminate the twist between the front and back of the canopy frame. That left a structure which had a rear bow that was too high on one side, because the welding was crooked. Fortunately, the Incredible Hulk turned up next and he pounded the bow into position. Not so fortunate though, was the ripple-on effect that pushed up the side rail. Again, King Kong came to the rescue and the side rail is now back to where it was before.

I downloaded some more recent Vans instructions for the slider and they include a *dimension* for the internal distance between the roller tracks, 40 13/16". This is what I have, yet the side bows protrude out 1/8" at the front over the skin. At the rear, they fall inside by about 1/16". The rear setback seems about right.

As for alignment of the rear hoop versus the aft top skin, the instructions are vague: "When you have adjusted the rear track position so that the rear canopy bow/skin relationship is correct, match-drill the rear track to the fuselage..." So, WTF is "correct"?! As things have turned out, the surfaces are not quite even and the track is as far back as it can go, and therefore the frame cannot go any lower at the rear. Any further manipulation is probably going to make things worse...

Next will be to fit cut and fit the bubble, then I will see whether it's time to join the Sika/'poxy crowd!!

Thanks for sharing!
Paul.
 
Hi all just want to jump in here.
This is what i am planning on doing. Any comments?

John, That is how I did mine, results acceptable. Except I made aluminum shims where needed instead of flox. Aluminum skirts came out looking good. If you let the flox set up and then level it out nicely I don't see why that wouldn't work as well.
 
It's no wonder that many builders resort to Sikaflex and fibreglass, and that the RV-14 is tip-up only. The combination of Vans design, quality control and instructions for the slider is absolutely shameful (but I still love dreaming about flying it one day).

Anyway, today King Kong turned up and helped to eliminate the twist between the front and back of the canopy frame. That left a structure which had a rear bow that was too high on one side, because the welding was crooked. Fortunately, the Incredible Hulk turned up next and he pounded the bow into position. Not so fortunate though, was the ripple-on effect that pushed up the side rail. Again, King Kong came to the rescue and the side rail is now back to where it was before.

I downloaded some more recent Vans instructions for the slider and they include a *dimension* for the internal distance between the roller tracks, 40 13/16". This is what I have, yet the side bows protrude out 1/8" at the front over the skin. At the rear, they fall inside by about 1/16". The rear setback seems about right.

As for alignment of the rear hoop versus the aft top skin, the instructions are vague: "When you have adjusted the rear track position so that the rear canopy bow/skin relationship is correct, match-drill the rear track to the fuselage..." So, WTF is "correct"?! As things have turned out, the surfaces are not quite even and the track is as far back as it can go, and therefore the frame cannot go any lower at the rear. Any further manipulation is probably going to make things worse...

Next will be to fit cut and fit the bubble, then I will see whether it's time to join the Sika/'poxy crowd!!

Thanks for sharing!
Paul.


Paul, You are on the right track but as you have found when you bend one part of the canopy frame - another part moves. No easy answer, just think about the effect of each bend.
As for the tracks and aft skin match up it helps to think from the outside in. The end result desired is to get the skirts to fit nice with the skins. So on the sides the skin will direct where the skirt wants to go, and the skirt will decide where the frame goes, which dictates where the roller goes, which tells you where the track goes. Similar on the aft skin, the idea is to match top of canopy bubble with aft skin. If you use Sika, you can shim easily between canopy frame and bubble when you bond the two together.
Not sure what you mean when you say the aft track is a far back as it can go. You move the track back to lower the canopy frame as required to get a flush fit of the canopy frame/bubble assembly to skins. Re-cut and re-bend the skin as required to move the track where you need it. Again, think outside in.
 
Paul, You are on the right track but as you have found when you bend one part of the canopy frame - another part moves. No easy answer, just think about the effect of each bend.
As for the tracks and aft skin match up it helps to think from the outside in. The end result desired is to get the skirts to fit nice with the skins. So on the sides the skin will direct where the skirt wants to go, and the skirt will decide where the frame goes, which dictates where the roller goes, which tells you where the track goes. Similar on the aft skin, the idea is to match top of canopy bubble with aft skin. If you use Sika, you can shim easily between canopy frame and bubble when you bond the two together.
Not sure what you mean when you say the aft track is a far back as it can go. You move the track back to lower the canopy frame as required to get a flush fit of the canopy frame/bubble assembly to skins. Re-cut and re-bend the skin as required to move the track where you need it. Again, think outside in.

Thanks Mark,
The aft sliding track is right back against the bent down flap in the skin, and the bend line in the flap is at the edge of the bulkhead flange, so I don't think it can be re-bent. The rear needs to drop probably 1/8". I will have another look at it today and project the line of the canopy bubble onto the skin, maybe a wider cover strip will do the trick.
Your explanation for fitting helps and I wish Vans would put that sort of overview in their instructions, it could save so builders much time and frustration.
Cheers,
Paul.
 
...Next will be to fit cut and fit the bubble, then I will see whether it's time to join the Sika/'poxy crowd!!
It was a long time ago, but I remember that fitting the canopy to the frame turned into a battle for dominance between steel and plexiglass, resulting in a dimension/shape stalemate. It was only after the frame and bubble were united that it became clear what adjustments were needed and where. I never could get the metal skirts to fit, so I glassed ones in. The slider mechanism would bind here and there for the first couple years, but after 15 years it functions beautifully. My experience is a result of my poor performance as a first-timer, not a manufacturing problem, I believe
 
Well I had to stop working on the canopy frame for a while and move onto other things. Now I'm back at it with a better attitude. At least for a while. I'm also prepping for SikaFlex but that is the next step. For now I need to figure out how close is close enough.

My latest question is in regard to the instructions where it says "The rear bows of the canopy frame closely match the contour of the F-7112 skin but are inset about 1/16"."

I assume this means the outboard edge of the rear bow, but it's not specific and if you assume the wrong edge I'm guessing it would be a big problem. The other thing is it doesn't really say how closely you need to match the contour.

Any clarification on this would be helpful.

At the moment I'm focusing more on the fore / aft position, but that is also related since the fore / aft position of the rear track assembly also sets the height of the rear bow.
 
It is the outside edge of the rear bows that needs to match the profile of the aft skins.

The way it is all supposed to work is that when the plexi canopy is mounted on the frame, and the rear skirts are mounted on the plexi, the canopy will close with the skirts just touching the aft skin. If the skirts are too low (because the hoops were too low) then the canopy won't be able to slide fully forward and won't close. If the skirts are too high (because the hoops were too high) then there will be a gap for cold air to rush in make your neck cold.

I think the best way to check the hoop position versus the aft skins is with the plexi mounted, so that you can simulate the aft skirts and see where they contact the aft skins. The thickness and shape of the plexi at the back (depending on how you made the cuts) can also affect how the skirts lay down.

Some people make the skirts out of fiberglass instead of aluminum to get a potentially better fit.

That's the theory anyway, I have been closely following a buddy who is a few steps ahead of me on the canopy. I'll be resuming work on mine soon too, now that the weather is warming up enough for the plexi work.
 
Bow

The other concern is making sure the canopy will open. I've seen bows so close they hit the skin as they open.
Fiberglass one piece layup is easy and will sit flush when closed. See the links on my blog (link below).
 
Thanks for confirming my thoughts. I'm still trying to get my head wrapped around this whole thing.

I'm thinking my next steps are to adjust the rear track position to get the correct height of the rear bow (1/16" inset) and then attach the rear track. Then move onto finalizing the shape of the rear bows. Can the rear track be too far forward? I know to check the screw positions. Is there any risk using this approach? To Larry's point I'd like to be able check that the rear bow will clear the aft fuselage. At the moment it seems like I need to eliminate some of the variables.
 
Sikaflex

The instructions were written for the plexi riveted to the bow. With sika, it will tolerate not so exact alignment and needs a gap from the bow to the plexi for flex. I found the sima made up for a lot of varability.
 
Canopy track

Thanks for confirming my thoughts. I'm still trying to get my head wrapped around this whole thing.

I'm thinking my next steps are to adjust the rear track position to get the correct height of the rear bow (1/16" inset) and then attach the rear track. Then move onto finalizing the shape of the rear bows. Can the rear track be too far forward? I know to check the screw positions. Is there any risk using this approach? To Larry's point I'd like to be able check that the rear bow will clear the aft fuselage. At the moment it seems like I need to eliminate some of the variables.

If you plan Supertracks, you may want to fabricate a new canopy track. Vans sells the aluminum.
I kept notes on my blog. Check this page.
http://wirejockrv7a.blogspot.com/p/finishing-kit.html?m=1
 
I'm not planning supertracks. For now I'm trying to stay on track with a more standard build. Hard to say that with a straight face as I'm prepping for Sikaflex.
 
Sika

I'm not planning supertracks. For now I'm trying to stay on track with a more standard build. Hard to say that with a straight face as I'm prepping for Sikaflex.

I wrote a series of articles in Kitplanes on that subject too! :D
Check my blog
 
Thanks for confirming my thoughts. I'm still trying to get my head wrapped around this whole thing.

I'm thinking my next steps are to adjust the rear track position to get the correct height of the rear bow (1/16" inset) and then attach the rear track. Then move onto finalizing the shape of the rear bows. Can the rear track be too far forward? I know to check the screw positions. Is there any risk using this approach? To Larry's point I'd like to be able check that the rear bow will clear the aft fuselage. At the moment it seems like I need to eliminate some of the variables.

It's better if you can defer drilling the rear track until later on because apart from fwd and back positioning you may also need to move it left or right slightly to get a good fit. It can be held in place temporarily with duct tape. Re-positioning by 1/16" can make a surprising difference.

If the rear track is too far forward then the canopy frame will be too low at the back. You can adjust the bend in the track but only very slightly to raise or lower the canopy.

Your next step should be to adjust the aft bows as needed to match the contour of the rear fuselage skins. You can project the surface of the skin onto the canopy bows in the closed position using a straight edge at various points around the radius of the aft fuselage. Support the canopy frame with wood blocks at the locking pin locations over the side tracks at the correct height (parallel over the side tracks). Note when you bend the aft bows it can have a knock-on affect on the side tubes and push them in or out. :mad:

The attached photo is of the levers I used to adjust the aft bows by gradually tweaking the bends to get a better fit. The frame that I received from Vans was welded crooked at the back, including the mounting point for the UMHW sliding block. It would be advisable to drill the bolt hole for that block in situ with the track, because if it is mis-aligned then it will jam.

I discovered that the bows were not quite right only after cleco fitting the plexi to the frame and checking the fit of the whole thing in the fuselage. I carefully modified the bend and was apprehensive that the holes in the plexi would move out of alignment, which they did very slightly but not enough to be an issue because the holes are not yet final sized for the rivets.
 

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Paul,

I'm not sure about the levers that you show. Did you slip those over the rear bows?

I do think I need some way of doing more localized bending.
 
Levers

Paul,

I'm not sure about the levers that you show. Did you slip those over the rear bows?

I do think I need some way of doing more localized bending.

Hi Ray,

Yes the levers slip over the rear bows and can be positioned for localized bending. The holes in the 3x1.5" wood are chamfered to avoid kinking the tube and the slot is to slip it on and off the tube. I resorted to these levers in desperation because earlier efforts by hand/knee and clamps/curved blocks were not successful in this location. Some of the surface finish got a bit scratched up so I plan to re-spray the frame before final assembly.

Cheers
Paul
 
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Colors

Hi Ray,

Yes the levers slip over the rear bows and can be positioned for localized bending. The holes in the 3x1.5" wood are chamfered to avoid kinking the tube and the slot is to slip it on and off the tube. I resorted to these levers in desperation because earlier efforts by hand/knee and clamps/curved blocks were not successful in this location. Some of the surface finish got a bit scratched up so I plan to re-spray the frame before final assembly.

Cheers
Paul

Sherwin Williams makes a white almost an exact match to Vans white powder coat. I believe it is cheron white, but will check next time I am near the plane’s house. It is the same color in jet flex interior and aycroglow exterior paint. JMHO YMMV
 
Ok Paul I've got it now, makes sense.

Yeah the other day I had the bow clamped in my bench vise with a couple of wood blocks to protect the finish. I couldn't get enough pressure, the bench started sliding. So then I put one foot up on the vice. OMG I needed a picture of that for my log. lol :D

I may give your lever idea a try. At the moment it seems like I'm playing whack a mole.
 
The other concern is making sure the canopy will open. I've seen bows so close they hit the skin as they open.
Fiberglass one piece layup is easy and will sit flush when closed. See the links on my blog (link below).

Mine did this, at both lower corners. Vans confirmed it is fine to trim the skin until it clears.
 

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Ok Paul I've got it now, makes sense.

Yeah the other day I had the bow clamped in my bench vise with a couple of wood blocks to protect the finish. I couldn't get enough pressure, the bench started sliding. So then I put one foot up on the vice. OMG I needed a picture of that for my log. lol :D

I may give your lever idea a try. At the moment it seems like I'm playing whack a mole.

I know exactly what you mean about the moles! One day we will get over it.
 
Paul, the use of your levers seems to be helping. I put the canopy frame in my vice and then use one of the levers to make localized bends or to straighten. I still have more work to do but this is a great help.

I do have one more question for the group. I'm curious how much of a gap you are seeing when you slide the frame back? With the side bows inset as suggested in the instructions it seems like there may not be too much clearance as the canopy frame slides back. I know some have commented that they trimmed the aft skins slightly, but I would prefer not to have to do that.
 
Bows and skins

Paul, the use of your levers seems to be helping. I put the canopy frame in my vice and then use one of the levers to make localized bends or to straighten. I still have more work to do but this is a great help.

I do have one more question for the group. I'm curious how much of a gap you are seeing when you slide the frame back? With the side bows inset as suggested in the instructions it seems like there may not be too much clearance as the canopy frame slides back. I know some have commented that they trimmed the aft skins slightly, but I would prefer not to have to do that.

Yep. That's another Mole!
You want it to clear the skin edge either side. Too much clearance and the canopy will be wider than the fuse. Remember the plexi will pull the bow out so the bow has to be adjusted to compensate. I suggest measuring the bow carefully without the plexi then again with the canopy clamped. The difference is how much the bow must be adjusted. It may not be equal fore and aft. Too much or too little and the rollers bind. Whack them moles!
 
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