Help to make R913 fit R912

Hello

I’m having a few issues getting the R913 rudder counterbalance skin to fit nicely on the R912 rib.

The skin wants to sit forward of where it should be and ends up with the clecos wanting to ‘slant’ backwards as I hope I’ve illustrated with the pictures. Clecoing every hole doesn’t really seem to make any difference, they’re still loaded in shear with the skin holes wanting to sit forward of where the rib holes are.

This is the second 912/913 set of parts I’ve had and the issue seems to be there with both of them.

When I went to rivet the first one it resulted in the rivets not wanting to sit square in the holes, with predictable poor results.

I’d appreciate any input on how to persuade the things to sit nicer together before I drill them.

Thanks very much.

I thought this looks normal for sheet metal work. You are yet to fit the lead counter balance weight so the parts will move a bit too. I also think the parts need more edge deburring though

Thanks Phat. That’s what I thought last time but the fit seemed to be further out than any other part and even when fully clecoed up and squeezing one rivet at a time the shear between the skin and the rib would make the rivet sit squint in the hole and make it very hard to set right.

There’s been no deburring or any prep other than fluting the rib at all done on these parts, this is just a dry fit.