[Thermos]

Hello all,

I've just finished match-drilling the rib-to-spar holes in my left wing - or most of them, at least - and am wondering what to do about those spar flange and rib holes that will eventually be riveted in assembly with the wing skins.

Seems like those holes should be match-drilled with the skins in place to make sure everything fits ok, but there's no way to debur the spar flange once the ribs are riveted in place. I asked Van's, even they didn't have a definite answer.

If you've finished your wings, what did you do with those holes?

Thanks,

Dave

 

[alpinelakespilot2000]

Match drill them now, debur, and then match drill again when the skins are on. That way you can get the majority of the burrs out. Once you put the skins on I think you'll find that (at least on the spar holes) the holes in the skin will match up real nicely and really require nothing but drilling up to size so you won't really be adding any burrs or chips to the equation. That's how I did mine anyway with no obvious issues. Good luck.

 

[RV7ator]

No Need

Dave,

Just drill the pre-punched holes to final size on the components right out of the box, dimple or countersink as appropriate, assemble and rivet. You aren't going to improve upon the matched hole machine accuracy by fitting everything up before drilling. Also, the one and two-hole "tab" rib flanges like to pivot out of alignment, so if you try match drilling you'll probably elongate them.

Watch out for assembly sequence gotchas Van's doesn't mention. For instance, set the most forward spar flange-to-main rib rivets in the ribs behind the tank before installing the inner main skins. If you don't, that rivet is hell to set because the skin edge is almost on it, leaving no room for a set. C'sink these few holes in the spar for a rivet, not extra deep for a skin dimple as all other holes.

John Siebold