canopy deck not level

Arg. When I applied the gentle curve to my longerons, I guess a twist resulted which I hadn't noticed before. My canopy decks do not sit level in the lateral direction. They are tilted upwards in the inboard direction. Photo below. Is this going to cause me a problem later? I can push it level with my hand, so I'm wondering if I should install some sort of angles or something in there to pull it down level. Thoughts?

Interfaces with canopy gasket. Don't worry - keep building!
Jim Sharkey
RV6 - Tip-up

Just to clarify, i'm building a slider... might I have a problem with the canopy binding in the track with my decks angled like this?

The slider is difficult enough to fit when everything is in alignment, plumb, and square. I think you are going to have some troubles with the wheels rolling in the slider rails properly if you don't correct this now. If it were me, I would fix this. This could also make riveting your side skins funky.

Just my $0.02....

Later on, when you are measuring the wings, be sure you don't use a level across the decks to make sure the fuselage is level. Use the center section as your reference.

idea for a fix

This could also make riveting your side skins funky.

Click to expand...

My side skins are actually already all riveted on, as are the canopy decks.

It's pretty easy to push the deck down level with my hand, so the idea I had for a fix is the following. Attach a piece of 1.75x1.75 angle agains the side-skin and the bottom of the canopy deck, as shown in the diagram below. This would add a bit of weight, and some (NAS 1097 small-head) rivets visible on the side skin, but would also serve to reinforce the canopy deck a bit. Thoughts??

If those are that far off kilter, how does your side skin to longeron interface look?

Can't imagin that it is nice and flat with that much twist in those longerons.

I can't say for sure, but I think doing this might pull the side skins out of position slightly at the locations of the angle brackets. You would be attaching to relatively unsupported skin. It probably wouldn't move a lot, but I think it would be visible depending on how powerful the spring force of the canopy deck is.

It's hard to tell in your photo...how much gap is there at the outside edge. Looks like maybe 1/16"? If that is all (with my experience of installing more than 1/2 doz sliding canopies), I wouldn't worry about it. If it is more than that, I would bond a thin strip of aluminum on the bottom outboard edge of the canopy tracks to act as a spacer when you mount them to the canopy deck. This would make the tracks properly aligned and the elevation difference would not be any issue (there is a lot of latitude when doing the actual fit of the frame

prkaye said:

My side skins are actually already all riveted on, as are the canopy decks.

It's pretty easy to push the deck down level with my hand, so the idea I had for a fix is the following. Attach a piece of 1.75x1.75 angle agains the side-skin and the bottom of the canopy deck, as shown in the diagram below. This would add a bit of weight, and some (NAS 1097 small-head) rivets visible on the side skin, but would also serve to reinforce the canopy deck a bit. Thoughts??

Click to expand...

No Worries

Hi Phil,
Here's my experience:

I've seen a few builds that looked just like your photo. Your 'upward bend' of the longeron appears to start at the rivet line and get progressively worse as it goes inboard. It is sometimes 'expected' that aluminum will 'curl' when it's subjected to a long row of rivets close to an edge.....such is the case here.....especially if they are slightly overdriven. It's also possible that you had a curl in the decks before you riveted them in place. Before you go drilling any holes anywhere read a little more .

It looks like a 'no biggie' to me. I'd just take 2 pieces of 3/4" angle about the same length of the deck. Tape one piece to the 'inside' (vertical 'side' and top 'armrest' portion') of the deck (trim if needed) and tape the other piece to the outside (inboard facing vertical 'side') of the deck. You make a 'sandwich' with the vertical inboard portion of the deck in the middle of the angle. Then just take a C clamp and clamp it on the whole works grabbing the 'inside' angle and the 'outside' angle. The adjustable 't' of the clamp will be facing inboard of course. Then just tighten the clamp at one end and start 'working' the deck down. Just go a little at a time and work your way to the other end in about 4" increments. Don't try to get it all at once....just gently work back and forth and I'm sure you'll end up with a nice straight deck when you're done. Keep an eye on the the outside of the fuse side skin where the permanant angle is riveted on......I seriously doubt that you'll see any movement there but just keep an eye on it. You 'could' do this without the 'angle sandwich' but you'd end up marring the deck.....the angle will allow you to work the deck without leaving any marks. My guess is that it will take you all of 20 minutes to get this right.

Just 'get it close' and you'll be OK....I figure you'll be able to get it perfect! As long as one deck isn't running uphill and the other downhill your rollers will run the tracks just fine (as long as the tracks are parallel ). If one or both tracks are canted in or out a tad you can make that up with the bracket that holds the roller and it will operate just fine....take a CLOSE look at some sliders next time you're at Oshkosh. Some look just like yours does now (or canted down) and the canopy rollers run fine.

This was a little difficult to put into words so feel free to call me if you want some 'verbal' help. Slip me an email if you want my number.

Good luck...be sure to post some 'after' pictures......as I said....yours isn't the first and won't be the last. Your pics will certainly help others.

prkaye said:

Arg. When I applied the gentle curve to my longerons, I guess a twist resulted which I hadn't noticed before. My canopy decks do not sit level in the lateral direction. They are tilted upwards in the inboard direction. Photo below. Is this going to cause me a problem later? I can push it level with my hand, so I'm wondering if I should install some sort of angles or something in there to pull it down level. Thoughts?

Click to expand...

Thanks guys!!
I spent some time with clamps and vice grips and some muscle "working" it this weekend, and it has improved somewhat. If I put a level across the deck and tip it up until the bubble is centered, the gap between the bottom of the level and the deck at the outboard edge is about 1/16" (maybe a hair above this on the worse of the two). The skin to longeron rivets along here look fine, appears straight with no obvious bend outwards in the side skin.
As pointed out above, when I took a closer look at my suggested fix tonight I realised it would not work becaues the side skins are unsuppored and the skins would just get pulled in instead of pulling the deck down. As I was dozing off this evening it occurred to me the best solution may be to wait until canopy fitting time, and make a long "wedge" spacer or shim to sit under the canopy rail (between the rail and deck) to hold the rail level. A thin piece of aluminum ground down to a wedge shape should do the trick.
Rick - I'm not sure I can visualize exactly what you mean on how to position those angles, but the general idea of "working" the thing down is what I've been doing, with limited success. I think I've reached the point now where I'll leave it until it's time to fit the canopy and make up the remaining with a shim.
One thing about getting to this part of the kit, is I'm making a big list of things to look closely at when I make my first-ever trip to Oshkosh this year! Looking forward to meeting some of you at the RV BBQ too!
Thanks again!

Phil,
Don't further restrict access to the bottom opening of the canopy decks. It's tough enough getting a tool in there when you bolt on the slider rails and roll bar.
Steve

OK, update. After spending a couple of hours this evening working on one of the decks, I've resolved that at this point it's pretty much impossible to modify the twist in the longeron (to level it out in the are of the decks) by working at it with clamps and muscle. I've got them both now so that the inboard edge of the canopy deck is less than 1/16" higher than the outboard edge. Since the canopy rails don't span nearly the entire width of the deck, this means the thickness of shim I will need should be considerably less than 1/16". Making a very thin wedge-shaped shim like this may be very tricky, but for now I'm going to move-on and worry about it when I fit the canopy rails.

I did ask Vans about this, and they replied that this is a very uncommon problem so they don't have a canned solution for it, but that it could very well pose a problem for the slider. They mentioned that twisting the longerons now would be extremely difficult (as I have found) and suggested the shimming option.

One night's lost sleep, but I'm optimistic now that it will be OK in the long run.

Not worth losing sleep over....

prkaye said:

OK, update. After spending a couple of hours this evening working on one of the decks, I've resolved that at this point it's pretty much impossible to modify the twist in the longeron (to level it out in the are of the decks) by working at it with clamps and muscle. I've got them both now so that the inboard edge of the canopy deck is less than 1/16" higher than the outboard edge. Since the canopy rails don't span nearly the entire width of the deck, this means the thickness of shim I will need should be considerably less than 1/16". Making a very thin wedge-shaped shim like this may be very tricky, but for now I'm going to move-on and worry about it when I fit the canopy rails.

I did ask Vans about this, and they replied that this is a very uncommon problem so they don't have a canned solution for it, but that it could very well pose a problem for the slider. They mentioned that twisting the longerons now would be extremely difficult (as I have found) and suggested the shimming option.

One night's lost sleep, but I'm optimistic now that it will be OK in the long run.

Click to expand...

The rollers actually have quite a bit of slop in them. I would really doubt that you will have any problems with them binding.