Drill Bit Sharpener....
My neighbor had a drill doctor I sharpened a whole box of old bits with. Worked good. When I was a bodyman I would resharpen my 1/8" bits I used for drilling spot welds for my blair cutter on a bench grinder. I got real good at it and just resharpen all of mine now on the bench grinder. I would say 1 out of 10 I messed up and had to redo.