"Tom Gardner" wrote in message
. ..
Major NG sore spot! Drill Doctors are CRAP!!! One of my guys has one and
brought it in and sharpened a bunch of drills that then wouldn't cut.
Upon
inspection they had a slight negative rake Hmmmm.

That has to be some wicked grinder! Rake angle on twist drills is
established by the helix of the flute. Therefore, regardless of how the end
of the drill is ground, rake angle is not affected.

If you're telling us that the drill was higher at the heel than at the
cutting edge and wouldn't cut because the lip was lower than the heel, then
I would suggest to you that it had negative *relief*, not rake. They are
not the same, and should not be confused.

Harold