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Spar Bolt Clearance - Wing Fitting.

mike newall

Well Known Member
Sponsor
I have reviewed previous threads regarding this but some of the threads were a little old.

We are about to mount the wings and have found that the fit and finish of the doublers on the spars and spar boxes are less than perfect.

I have standard 7/16" bolts as temporaries and they mic out at a good size.

What concerns me is the line up of the doublers to the spars - it looks like they need a good reaming but I am loath to start doing this.

What have people been doing recently with current production kits to get around this problem.
 
Well, once the doublers are already in place and riveted on I would not ream them. I tried to open them up a bit before putting it all together in hopes it would make it easier. It didn't. In my case as I drove in the final bolts they really wanted to catch on the edge of the doubler and I had to carefully thread them past it. the nuts pulled everything down into place in the end so it's fine.

For temporary fitting I had some 7/16 bolts that were ground down to a point so they when through the doubler fine.
 
I had this issue with both sides. Vans did not believe me when I told them the doubler was not lined up and actually covered ever so slightly the hole. The first time I called them they told me it was impossible for this to happen.
After numerous calls , photos and measuring with precise Starrett Ball gauges, I got their attention. They told me not to ream out the hole.
The fix was to file just the lip or edge that was obstructing the hole. It was stressed that I was not to file the hole in the spar at all. just the doubler. This took a very very long time to accomplish. The hole was then primed per their instruction. Call Vans and ask for engineering. If you do not get one of their engineers call back until you do!
 
I had this issue with both sides. Vans did not believe me when I told them the doubler was not lined up and actually covered ever so slightly the hole. The first time I called them they told me it was impossible for this to happen.
After numerous calls , photos and measuring with precise Starrett Ball gauges, I got their attention. They told me not to ream out the hole.
The fix was to file just the lip or edge that was obstructing the hole. It was stressed that I was not to file the hole in the spar at all. just the doubler. This took a very very long time to accomplish. The hole was then primed per their instruction. Call Vans and ask for engineering. If you do not get one of their engineers call back until you do!

This is exactly what I did during the assembly of the spar and formers. The holes in my formers did obstruct the spar holes by a very small amount. This probably isn't helpful on a quick build but might help someone down the road on a slow build.
 
Thanks chaps.

Once again, I am afraid this calls into question the quality of the Philippine assembled kits.

Our 7 was a CZAW, Czech assembled one and everything, I mean everything fit like a glove.

To date on the 8, I have had 2 days disassembling structure to move forward, I must have had to drill out and replace at least a dozen nutplates because they were wrong spec and now this......

OK,

No reaming, mucho Dremelling by the sounds :cool:

Thanks for the replies.
 
Just stumbled upon this thread while searching for something else. I have exactly the same issue with a -7 center section spar, slow build, purchased over a decade ago.

One of the downsides of having a forum so subdivided. I don't have time to monitor every subdivision.

Charlie
 
Same on mine. I could see the doublers getting blank on one side trying to insert the bolts. Here I removed just a tiny bit only on the doublers at this location. Vans did say don´t ream the holes and it was not necessary.
I also had bolts from a hardware store for temporary fitting of the wings but I noticed the problem already when trying to insert the close tolerance bolts in the fuse only.
 
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