Rollover Structure Issue - bad part?

I got the rollover structure all clecoed together and slid onto the bases(attached to fuse) without any issue, but when I went to cleco the structure to the bases, I found one side was so bad that the clecos could not be "persuaded" into more than one hole, all others were too badly shadowed. I brought all the parts back to the bench for measuring and found that the base-attach holes in the right side roll bar were significantly off-center.

Obviously I'll send a note to Van's, but has anyone else run into this?

I just spent all day yesterday dealing with what appears to be the same issue. I took everything apart and verified the F1231D hole pattern is the same as F1231A. Pattern was the same, but F1231D was not centered in F1231A. I ended up filing F1231D locally to make just enough room for F1231C to fit between the parts with a small amount of bending outward of the 1231A flange. Not sure if everyone has this issue, or Vans has a batch of poorly aligned parts.

I am at the same point and my parts were mfg late 2018 I believe. I have not had these issues described.

I can not say about the 12 but that part on the 7 needed substantial tweaking to get it the correct width and flat. It is still joined at the top isn't it? A tiny misalignment there makes a huge difference. We are talking stamped sheet metal parts, regardless of precision holes.

BillL said:

I can not say about the 12 but that part on the 7 needed substantial tweaking to get it the correct width and flat. It is still joined at the top isn't it? A tiny misalignment there makes a huge difference. We are talking stamped sheet metal parts, regardless of precision holes.

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The pictures were taken on the bench with the structure disassembled - the best possible chance for alignment. There is simply no adjustment in the fit-up, the base is press-fit into the roll bar.

As an engineer, I spent my first five years in a stamping plant, some of it as a supervisor in the tool and die shop and some in quality control, among other areas. This F-1231A-FR isn't even remotely acceptable in my opinion. Even the -FL part never would have left our shop, but it's at least close enough that some light filing and tweaking will get it usable.

It looks to me that the holes were punched before the forming operation, which is less than ideal and unnecessary for these particular holes. If that's not the case, then the fixturing for the punching operation is extremely poor or has failed in some way.

Maybe these holes should be left to the builder to match-drill using the CNC'd base?

AaronG said:

I just spent all day yesterday dealing with what appears to be the same issue. I took everything apart and verified the F1231D hole pattern is the same as F1231A. Pattern was the same, but F1231D was not centered in F1231A. I ended up filing F1231D locally to make just enough room for F1231C to fit between the parts with a small amount of bending outward of the 1231A flange. Not sure if everyone has this issue, or Vans has a batch of poorly aligned parts.

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When did you get your kit? I took delivery in early March 2020.

BobbyLucas said:

Maybe these holes should be left to the builder to match-drill using the CNC'd base?

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With over 700 RV-12's now flying, and at least twice that many fuselage kits likely sold to date, there is strong evidence that the parts as designed has worked fine the majority of the time (this is the first instance of this problem that I am aware).

I suggest the shortest path forward towards resolving this would be to contact someone in support at Van's and let them look into it.

I got my kit in mid-2018, so likely not a batch issue. I could have probably made it work with enough pounding with a rubber mallet per the directions, but don’t really like building planes that way.

Got the final answer from Van's - my F-1231A-FR is out of spec and they will be sending another.

Interesting side-note: The roll bar frames are hydroformed.

BobbyLucas said:

Got the final answer from Van's - my F-1231A-FR is out of spec and they will be sending another.

Interesting side-note: The roll bar frames are hydroformed.

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Good to know, a good example for others: do your homework.

Got my new part from Van's and it was a dead-nuts match to the machined base.

I had exactly the same problem and I got a new one from Van's without payment.