Craig

Craig

Well Known Member
I spent all day today drilling the 3/4" holes in all the wing ribs of my RV-8 QB wings.

The #3 unibit has 3/4" as its largest hole size. It was perfect for many of the holes. However, since this is a Quickbuild wing, the bottom skin is installed on the inboard half of the wing. The wingwalk ribs are too close together to get a drill in there. The ones under the access panels are too close together for a drill that will accept a 3/8" shank bit. An extension to the unibit would be perfect, however the extensions that I found at the hardware stores and Avery were for 1/4" shank bits. The #3 unibit has a 3/8" shank, so the extensions won't work.

I ended up having a machinist friend bore out a 1/4" extension to 3/8", but it wasn't easy.

I'm interested in how other people solved the logistic problems.

Craig
 
I bought a set of "Brand-X" Unibits at Harbor Freight that use the small hex drive (1/4"?) common to electric screwdrivers and accessories. They also have a long hex drive extension. I drilled a pilot hole with a 12" #30 bit, opened them up to 1/2" with the "Unibit" that starts at 1/8", then ran the 3/4" bit through. The drilling was fairly easy, the deburring somewhat harder, and pulling that corregated conduit through the wing walk area was a bear. All done now, though and a good result.
 
3/8" extensions

I found 3/8" extensions (12" long) at Home Depot. They've come in handy a couple of times.
 
Thanks for the quick replies.

I suppose I could have found the right combination of unibits and extensions given enough time. I looked at Lowes and Home Depot today with no luck, and went with what I had available.

Craig
 
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