Re: machining copper (fwd)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Ed Phillips <evp-at-pacbell-dot-net> 

"Also, and this is one of those tricks of the trade, use a stone to make
a .015" or so flat on each cutting edge of the drill that is parallel to
the centerline of the drill and runs at a 90 degree angle
(perpendicular) to the workpiece. That will keep the drill from
"catching" when breaking through the bottom of the material on brass and
other soft materials. Drills modified in this manner will still work
fine on any other material, but will save you a trip to the emergency
room of your local hospital to re-attach severed fingers!

Ed Wingate RATCB"

	I hope no one here drills metal without clamping it down first, at
least "after the first experience"!  I have drills ground as you
described and they work quite well in acrylic as well as brass, for the
same reason.

Ed