Spar attach holes

[geraldmorrissey]

Just curious when the main spar and rear spar wing attach holes are drilled to full size.
Thanks
Gerry
Patrol #30 Wings.

[Barry]

Gerry, I will probably drill mine before I put the spars in the jig, I thought I could use those holes to bolt to the jig. Good question for the group.

[Mark Goldberg]

Gerry, on the kits we leave all the holes undersize so the wings can be match drilled to the fuselage after getting everything just right. Mark

[Barry]

I guess I better leave mine undersized, thanks Mark!

[Enewton57]

Also be carefull when you drill those to final size that you hold the drill straight. You will be going from steel through aluminum back to steel again. If you bit doesn't go straight through, you might end up with an oblong hole in the aluminum wing spar. The bit will go though the aluminum quite easily but if you are a little off whe you hit the steel, the bit will be pulled to center in the hole of the steel part and will oblong the hole in the aluminum. There are some drill jigs made specially for drilling the wingmounts floating around that you might be able to borrow.

[DesertBearhawk]

I have thought about this process all along, thinking ahead as it were. My thought has been to drill the tabs and spar to size BEFORE the mounts are welded to the fuze this way you can get everything lined up perfect and then weld it ...would that work?

[Enewton57]

I think its best to match drill them altogether to assure proper alignment of all holes. If you were very slightly angled on any of the holes, the bolt would not slip in. Also, by match drilling, you do have the opportunity to adjust the wing incidence slightly if needed and then drill the hole out to full size. Here is a link to the page on my website where I installed the wings and drilled the holes out to final size. Shown is the drilling jig that I used. Easy to make with some tubing and a steel plate.
(link removed due to URL change)