Re: milling circuit boards [source for collets and bits]

Bill: For a 1/4 to 1/8 (or 3/16) shank bits use the adapter bushings
from www.mlcswoodworking.com part #271. 4 bucks


For specialized bits for PCB routing (v-bits) check
http://www.thinktink.com/stack/volumes/voli/store/mechmill.htm

I use the 60 deg bits.

They have a tutorial about mechanical etching (milling).

Having a floating head with penetration control (adjustable nosepiece)
like those used and any good vinyl cutter makes for consistant depth
cuts (essential with V bit cutting). Also is really handy for general
purpose engraving,