In article .com,
"wright1902glider" wrote:

Hello everyone,

I'm back in the shop again with a new problem. That is, how to drill
accurate holes on-center through steel tubing.

I need to attach 2 short lengths of 1/2" EMT tubing parallel to the top
tube of a bicycle frame, one on each side. The EMT tubes will extend
about 20" forward of the bike frame. The frame tube is about 1" dia. I
want to drill horizontally through all 3 tubes and attach everything
with a pair of #10 machine screws.

Prob. is how to drill the holes on center so everything lines up. I
have both a drill press and cordless drills at my disposal.

Suggestions? Methods? Tools?

Thanx,
Harry
Wright Brothers Bike Guru
Wright 1902 glider
Wright 1899 kite

Any reason you've ruled out epoxy in lieu of the bolts? Seems like you
could make a nice neat job of it. You can get it in different colors, or
add pigment to the clear stuff.