I am fitting the F-711 bulkhead to the skin, and two parallel vertical lines of holes on the bulkhead (one line coming from the F-711A, the front part, the other from the F-711B, the aft part) do not align. Pretty much all the vertical holes on the F-711 bulkhead, not just few of them.
My guesstimation is that the worst hole is ~0.030" off, if I align one side "perfectly". Meaning, that an ideal hole covering both will be around, say, ~0.120", an -4 sized rivet (and the side that is aligned "perfectly" will be normal -3 sized rivets).
The holes on the skin are closer to each other compared to the holes on the flanges of the bulkhead. I cannot think of a way to make the holes on the bulkhead closer to each other. The flanges are bent the way the are bent, and I don't think I have any significant gaps between the bulkhead sides either.
There might be some vertical offset happening, too, but I think it is mostly the horizontal.
Before I ruin the holes in the skin (I've already enlarged them a bit with clecoes trying to fit the parts, but nothing too bad so far), what are my options?
1. I can try to "split the difference" and fit NAS1241 rivets (1/64" oversized rivet shank) on both sides. Lot of "ifs", but maybe I can drill (or even file) the holes very precisely and get away with +0.016" enlarged holes.
2. Give up trying and do the -4 sized rivets on one side. Edge distance is probably going to be okay for the most of the rivets, but there are 4 holes that attach the J-channel stiffeners which already have a very marginal edge distance on the top side of the flange. Maybe, I can move a hole a bit and make the edge distance to work both on the flange and on the J-channel.
3. Maybe, there is an option to make a special order for the part without the holes? Replacing the F-711B should take care of the issue (same way the F-712B bulkhead is made). I haven't reached Van's yet, don't know if that's a thing, though
Anything else I can do?
My guesstimation is that the worst hole is ~0.030" off, if I align one side "perfectly". Meaning, that an ideal hole covering both will be around, say, ~0.120", an -4 sized rivet (and the side that is aligned "perfectly" will be normal -3 sized rivets).
The holes on the skin are closer to each other compared to the holes on the flanges of the bulkhead. I cannot think of a way to make the holes on the bulkhead closer to each other. The flanges are bent the way the are bent, and I don't think I have any significant gaps between the bulkhead sides either.
There might be some vertical offset happening, too, but I think it is mostly the horizontal.
Before I ruin the holes in the skin (I've already enlarged them a bit with clecoes trying to fit the parts, but nothing too bad so far), what are my options?
1. I can try to "split the difference" and fit NAS1241 rivets (1/64" oversized rivet shank) on both sides. Lot of "ifs", but maybe I can drill (or even file) the holes very precisely and get away with +0.016" enlarged holes.
2. Give up trying and do the -4 sized rivets on one side. Edge distance is probably going to be okay for the most of the rivets, but there are 4 holes that attach the J-channel stiffeners which already have a very marginal edge distance on the top side of the flange. Maybe, I can move a hole a bit and make the edge distance to work both on the flange and on the J-channel.
3. Maybe, there is an option to make a special order for the part without the holes? Replacing the F-711B should take care of the issue (same way the F-712B bulkhead is made). I haven't reached Van's yet, don't know if that's a thing, though
Anything else I can do?