Another factor to consider is the "relief angle"- - - -the taper of the bit helix behind the cutting edge. If the bit isn't tapered back a little from the sharp cut edge, the bit will "skate" and overheat instead of cutting smoothly. Too radical of a relief, and the strength of the cut edge is compromised. That's a skill that just about has to be developed with lots of practice- - - -I don't know of any guide fixture that can do it consistently.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!