Slider roll bar question

After fitting the roll bar in place each side has about 1/8" gap when the other is flush with the fuselage top rail. I placed it on several other flat surfaces to verify the issue. I know shimming is always an option but it looks like I'm going to have to take a torch to get it squared up. Thought I'd get advice before heading down that road.

Doesn't the roll bar land right in an area where the longeron has a bend? I know it did on the -6 and the plans instructed you to shim it to plumb.

That's what I'd do in your case.

Roll bar

Mine was a little off too. Vans said to shim. However, don't cut or drill your forward brace until the canopy is complete. Then shim it to fit the canopy then cut and drill the forward bar.

Mine required a 3/16 shim, I ended up cutting and rewelding it.

Good advice Larry. Usually Vans Powder Coated steel parts fit well. I?m surprised the rollbar is this far off. I?ve laid it on several flat surfaces and it definitely is not square. I hate to take heat to it but I don?t want a bunch of ugly shims under this thing either. After laying it down flat on a table the passenger side is the one that is sticking up slightly. I?ll have to take a torch to get it square. I guess most people have to adjust side to side. Mine is within the 1/16? per the plans.

Yep your 1st pic looks pretty identical to mine. I put a shim in there and called it good.

Jibby, did you reweld it with MIG. I don’t have access to TIG. Man I’m pretty disappointed with Vans right now. The QC on this part would not be that difficult to get right!

I'd shim it and move on. Once the windscreen and 'glassed fairing are in place, it will barely be noticeable.

It's all about massaging it all and making it work. On my -9A slider, the main hoop sat nice and flat, but to match the hoop's contour with the canopy frame, I had to shim the frame up about 3/8" on one side at the roller, and make a side skirt that was 3/8" deeper.

Slightly asymmetrical, but wholly unnoticeable. You can only see one side of the plane at a time!!

I just got back from flying, I shimmed by roll bar and forgot all about it. I did look at it today after reading this post.

Van?s received the welding fixture for this roll bar earlier this year from the fellow that was building them, Van?s did some adjustments to it and it?s now in my shop. I just put a couple complete roll bars on my flat 1/2? thick aluminum table and they?re sitting flat. Maybe going forward they won?t need any shimming.

Yes, I used a TIG welder, I too was surprised at how far the roll bar was off, just couldn't live with it. I also have access to really nice TIG welders at work so the choice to cut and make it right was easier.

your roll bar seems to be way off. shims shouldn't be an problem from the structural point of view. I think you can forget about bending as the roll bar is extremly rigid. I would fabricate a triangular shaped shim for the passenger side and move on.

Roll bar

When I got the finish kit, I checked it for sitting level and it was off by 3/16. I complained, sent it back and the one I got in return was identical. Off by 3/16.

Russ, thanks for the update. After seeing the high quality and near perfect fit of the engine mount I was shocked at the roll bar. Guess I?ll just shim and move on then.

Roll bar fore-aft position

Apologies for the thread resurrection, but this seems like a good place for my observation/question. I have been studying the drawings (41, 42, 43) very carefully for my RV-7 slider roll-bar installation. I have drilled the #40 pilot holes for the 4 bolts into the aft canopy deck in the positions called out in drawing 42 detail A, and made the C-668 spacers, but haven't drilled the roll bar yet.



The left-right position of the roll bar seems clear: 7/32" inboard of the outboard edge of the canopy deck. But the fore-aft position appears to have two contradictory positions which differ by about 5/32". Looking at detail A above, it's clear that the front edge of the base plate is 3/8" forward of the centre of the forward bolt, which makes sense for a 2x edge distance on a 3/16" hole. That makes the aft edge of my roll bar line up with the aft edge of a rivet on the canopy deck, agreeing with the picture above. However take a look at Drawing 42 view C-C:



The 2 5/8" distance called out for the aft edge of the base plate appears to me to be inconsistent with detail A, placing the roll bar about 5/32" further aft, and also causing a violation of the edge distance for the forward bolt hole if that is drilled as per detail A. Obviously all of this would be expected to have a knock-on effect on the height of the aft edge of the sliding canopy as it falls down the 45 degree angle of the canopy slide rail as it is closed.

I am very puzzled. Both diagrams indicate the base plate is 5.25" long. I'm hoping that I'm not about to be told that the detail A bolt hole positions aren't correct and that my pilot holes are therefore in the wrong position! Is there any preference to bias the roll bar forward or back? I will email Van's but I'm wondering if I am missing something or if anyone else agrees with me that the plans are inconsistent here. As always, many thanks for any insights.

AndyWW said:

Roll bar fore-aft position

Apologies for the thread resurrection, but this seems like a good place for my observation/question. I have been studying the drawings (41, 42, 43) very carefully for my RV-7 slider roll-bar installation. I have drilled the #40 pilot holes for the 4 bolts into the aft canopy deck in the positions called out in drawing 42 detail A, and made the C-668 spacers, but haven't drilled the roll bar yet.

View attachment 60270

The left-right position of the roll bar seems clear: 7/32" inboard of the outboard edge of the canopy deck. But the fore-aft position appears to have two contradictory positions which differ by about 5/32". Looking at detail A above, it's clear that the front edge of the base plate is 3/8" forward of the centre of the forward bolt, which makes sense for a 2x edge distance on a 3/16" hole. That makes the aft edge of my roll bar line up with the aft edge of a rivet on the canopy deck, agreeing with the picture above. However take a look at Drawing 42 view C-C:

View attachment 60271

The 2 5/8" distance called out for the aft edge of the base plate appears to me to be inconsistent with detail A, placing the roll bar about 5/32" further aft, and also causing a violation of the edge distance for the forward bolt hole if that is drilled as per detail A. Obviously all of this would be expected to have a knock-on effect on the height of the aft edge of the sliding canopy as it falls down the 45 degree angle of the canopy slide rail as it is closed.

I am very puzzled. Both diagrams indicate the base plate is 5.25" long. I'm hoping that I'm not about to be told that the detail A bolt hole positions aren't correct and that my pilot holes are therefore in the wrong position! Is there any preference to bias the roll bar forward or back? I will email Van's but I'm wondering if I am missing something or if anyone else agrees with me that the plans are inconsistent here. As always, many thanks for any insights.

Click to expand...

I just checked mine, and the way I interpreted the drawings are that the 2 5/8" measurement from the indicated rivet in Fig C-C, locate the roll bar bottom plate fore and aft. For the position of the 3/16" bolt and 1/4" bolt, I drew a line (laterally, left to right) through the rivet in Figure A that has the 1/2" and 3 5/8" measurements from and used that to locate the bolts.

CharlesC said:

I just checked mine, and the way I interpreted the drawings are that the 2 5/8" measurement from the indicated rivet in Fig C-C, locate the roll bar bottom plate fore and aft. For the position of the 3/16" bolt and 1/4" bolt, I drew a line (laterally, left to right) through the rivet in Figure A that has the 1/2" and 3 5/8" measurements from and used that to locate the bolts.

Click to expand...

Thank you Charles. I am wondering if my difficulty could stem from my aft canopy decks being somehow further forward than the plans are indicating. I plan to check that carefully today. I got a reply from Van's but I don't think they understood my problem which is basically that I won't have edge distance on the roll bar bolt holes if I use the 2 5/8" dimension.

AndyWW said:

Thank you Charles. I am wondering if my difficulty could stem from my aft canopy decks being somehow further forward than the plans are indicating. I plan to check that carefully today. I got a reply from Van's but I don't think they understood my problem which is basically that I won't have edge distance on the roll bar bolt holes if I use the 2 5/8" dimension.

Click to expand...

I think that the actual dimensions are less important than it is to get the roll bar in the correct position relative to the sliding frame, when the sliding frame is in the correct position relative to the aft skin at the baggage compartment bulkhead. As you noted above, the sliding frame travels down the 45 degree track and this establishes the position of the aft hoops relative to the skin. If the hoops are too high or too low then the canopy aft skirts will not fit properly against the fuselage when the canopy is closed.

Each canopy frame is slightly different and also the dimensions will change while it is being bent into shape. So it is not really realistic to expect the called out dimensions for the roll bar to be correct for every situation.

If you can, I would hold off drilling the roll bar until the sliding frame has been adjusted and temporarily fitted to the fuselage.

PaulvS said:

I think that the actual dimensions are less important than it is to get the roll bar in the correct position relative to the sliding frame, when the sliding frame is in the correct position relative to the aft skin at the baggage compartment bulkhead. As you noted above, the sliding frame travels down the 45 degree track and this establishes the position of the aft hoops relative to the skin. If the hoops are too high or too low then the canopy aft skirts will not fit properly against the fuselage when the canopy is closed.

Each canopy frame is slightly different and also the dimensions will change while it is being bent into shape. So it is not really realistic to expect the called out dimensions for the roll bar to be correct for every situation.

If you can, I would hold off drilling the roll bar until the sliding frame has been adjusted and temporarily fitted to the fuselage.

Click to expand...

I thought a couple of snaps might help describe what we are talking about.
First off, I'm a first-time builder, this is what I've done.. I sure hope it is correct! I'm currently working on the canopy, so this is unfinished work.
The right angles and straight lines in the pictures look a bit distorted, in real-life the pieces are straight and at 90 deg. where they are supposed to be. In the first picture, you can see the 2 5/8" measurement from the unfilled rivet hole. That is to the back of the roll bar sole plate. The two little lines at the forward position denote the front of the sole plate and the lateral line through the rivet on the canopy deck.
The edge distance from the middle of the forward bolt to the edge of the sole plate is 3/8" and to the lateral line, it is 1/2".
In the second picture, the roll bar looks like it is canted inward, but it is not - the outside edge runs true to the fuselage outside skin (7/32" inboard).
My holes were drilled carefully to avoid nicking the longeron and I had to make the little spacers (underneath) twice. Getting the whole thing together was a chore, I ended up making a stack of spacer, washer, and nut and using a little super glue to hold them together while I slid them forward from the middle of the aft canopy deck.
My canopy frame (with the bubble resting on it) slides back and forth pretty easily. It drops down the 45 at the rear and the canopy is just lower than the turtle-deck skin.
I'm keeping my fingers crossed that this will come out right. . .
Hope this helps, Andy!

PaulvS said:

I think that the actual dimensions are less important than it is to get the roll bar in the correct position relative to the sliding frame, when the sliding frame is in the correct position relative to the aft skin at the baggage compartment bulkhead. As you noted above, the sliding frame travels down the 45 degree track and this establishes the position of the aft hoops relative to the skin. If the hoops are too high or too low then the canopy aft skirts will not fit properly against the fuselage when the canopy is closed.

Each canopy frame is slightly different and also the dimensions will change while it is being bent into shape. So it is not really realistic to expect the called out dimensions for the roll bar to be correct for every situation.

If you can, I would hold off drilling the roll bar until the sliding frame has been adjusted and temporarily fitted to the fuselage.

Click to expand...

Thank you Paul - I am going to try a temporary fitting of the slider frame before I drill the roll bar.

CharlesC said:

View attachment 60382
View attachment 60383
I thought a couple of snaps might help describe what we are talking about.
First off, I'm a first-time builder, this is what I've done.. I sure hope it is correct! I'm currently working on the canopy, so this is unfinished work.
The right angles and straight lines in the pictures look a bit distorted, in real-life the pieces are straight and at 90 deg. where they are supposed to be. In the first picture, you can see the 2 5/8" measurement from the unfilled rivet hole. That is to the back of the roll bar sole plate. The two little lines at the forward position denote the front of the sole plate and the lateral line through the rivet on the canopy deck.
The edge distance from the middle of the forward bolt to the edge of the sole plate is 3/8" and to the lateral line, it is 1/2".
In the second picture, the roll bar looks like it is canted inward, but it is not - the outside edge runs true to the fuselage outside skin (7/32" inboard).
My holes were drilled carefully to avoid nicking the longeron and I had to make the little spacers (underneath) twice. Getting the whole thing together was a chore, I ended up making a stack of spacer, washer, and nut and using a little super glue to hold them together while I slid them forward from the middle of the aft canopy deck.
My canopy frame (with the bubble resting on it) slides back and forth pretty easily. It drops down the 45 at the rear and the canopy is just lower than the turtle-deck skin.
I'm keeping my fingers crossed that this will come out right. . .
Hope this helps, Andy!

Click to expand...

Thank you Charles - these pictures are very helpful. I think my canopy deck is slightly too far forward. Here is a picture of the same area on my build (the roll bar is just resting there in the position suggested by Detail A):



The join between the forward and aft decks on your build is slightly aft of the mid-point of the two rivet holes in the side skin whereas in my build it is slightly forward of the mid-point. I think that explains why I am having a problem.

In the meantime I received a helpful reply from Tom at Van's who suggested walking the pilot holes aft, and also commented that the 3/8" edge distance is not as critical on steel as it is in aluminum. So I think I will follow his suggestion, as well as Paul's above. For future readers, I would suggest careful refence to both Detail A and View C-C on Drawing 42 before drilling in this area!

AndyWW said:

Thank you Charles - these pictures are very helpful. I think my canopy deck is slightly too far forward. Here is a picture of the same area on my build (the roll bar is just resting there in the position suggested by Detail A):

View attachment 60390

The join between the forward and aft decks on your build is slightly aft of the mid-point of the two rivet holes in the side skin whereas in my build it is slightly forward of the mid-point. I think that explains why I am having a problem.

In the meantime I received a helpful reply from Tom at Van's who suggested walking the pilot holes aft, and also commented that the 3/8" edge distance is not as critical on steel as it is in aluminum. So I think I will follow his suggestion, as well as Paul's above. For future readers, I would suggest careful refence to both Detail A and View C-C on Drawing 42 before drilling in this area!

Click to expand...

One other little wrinkle I ran into was that the plate that is welded to the bottom of the roll bar was actually different from left to right. The pilot side (left) was exactly 5.25 inches, with a little lip on the back. The co-pilot (right) side is a bit shorter, the lip at the back is missing! It is only about 1/8 inch, but these things add up.
I agree with Paul, it seems that at this point, we are building to what we have and the actual dimensions may vary a bit. As long as things go together and work - it seems that is the goal.
I also appreciate what Vans said about edge distance; it has always seemed to me that the thickness and type (aluminum vrs. steel for example) of the material should have an impact. I've looked and looked (too much) and there really doesn't seem to be a consensus about this.
Anyway, you said that you have only drilled the pilot holes and it really doesn't look like you are off that much. So, hopefully you will be able to
file and walk your existing holes to where you are comfortable with them.
Having just done this, I would advise that you take a good look with a mirror to ensure that when you upsize the holes they don't bite into the longeron. I don't know if this would be a tragedy, but for some reason I was pretty careful .
Cheers!