In Reply to: Drill bit sharpening help posted by Beth and Allen on July 19, 2018 at 20:05:29:
The key to sharpening drill bits is two pieces of geometry:
1) The flute angles need to be matched.
2) The flutes have to have sufficient relief angle to allow the sharpened cutting edge to engage the work ahead of the trailing edge.
When you run a properly sharpened drill you should get two continuous "curls" from the flutes. If you only get one curl one of the flutes is off and the drill will run oversize, hot, and off center. That is usable but not what you want and an off center sharpening job. If you get none both flutes are off, probably relief angle, and the drill is junk. It is unusable, won't cut worth a dang, and a PITA to deal with.
Hand sharpening a drill is a real skill and a jig with a cam action guide for generating the relief makes it a lot easier.