09-18-2012, 09:09 AM
(09-17-2012, 06:56 PM)EdK Wrote: And finally got started on my cat eye. I started with a 1/4" drill bit and went up to 1/2" in 1/32 steps. I'm pretty sure that's leaded steel but I'll find out when I go to bore it out.
Come on Steve, maybe he had good reason to spend a little extra time in the shop!
Since this site is all about learning Ed, this is how I would have done it:
I don't use a pilot drill for drills up to 1/2". Most of my smaller drills have a split point, so they don't require a pilot but even if they didn't, the chisel point on a 1/2" drill is not large enough to worry about. On drills over 1/2" I drill a pilot hole about the size of the chisel point so it takes less force to feed the drill. Even a 1" drill goes in pretty easy with a 1/4" pilot hole.
An incremental step to the final size will tend to make a rounder hole, but if that's important I'll normally ream or bore it to size.
Tom