[TheForge] Drilling stone

[Demon Buddha]

Jerry Frost wrote:

> You can also make drill bits from tubing and grit (diamond, etc.) Copper
> tubing works very well as the grit imbeds in the copper and cuts the stone
> better. The downside of copper is it's sensitivity to being twisted off in
> the hole by an over exuberant operator. <grin> A tubing bit has the
> advantage of being able to deliver coolant in an open circuit. Basically
> feed it down the tube and return it up the hole around the bit. This really
> helps prevent cuttings from jamming the bit in the hole.

	I will second this.  Diamond cuts VERY aggressively, but
	requires a gentle feed.  If you over feed, you actually slow
	your progress and ruin the drill.  Diamond is a very odd
	cutting medium and works in some counter intuitive ways.