Hi Derf,
In posting this, I just wanted to see if anyone had any better ideas (short of a lathe, that is).
This is an old method, and it works as long as you follow a few rules.
(1) Notice “front” written on it, this and the bolt heads always face me, even though I have carefully set the table to 90 degrees and NEVER move it, if it’s off just a little it would be off double if reversed. The hole for the tube is drilled with the same orientation as the tubes will be drilled.
(2) I run through a series of bits rather than trying to drill the finished size in one pass, and blow out the swarf between changes. I start with 3/32” (.094”), then go to #40 (.098”), then to #38 (.101”). I have done a couple out to 7/64” (.109”), but prefer to stop at .101”. This way I’m only taking out a few thou. per pass and don’t break bits, and still leaving about 1/32” wall thickness.
(3) This works for a lot of applications, I have several similar blocks drilled with different sized holes for everything from drilling old shot tubes to make trigger bushings, to drilling Tweco contact tips for peep-sight apertures, to center-drilling bolts and round stock, etc.
It’s only wood, so the holes (originally drilled slightly undersize) will eventually get loose…when this happens, I just “x” ‘em out and drill new ones.
It is a slow method, and I’m not in that big of a hurry. If however someone has something BETTER, I’m all ears…
Rex