anyone using the drill doctor? i have the pro model, DD750, sharpens up to 3/4 bits. it works fantastic. 30 years ago, an old timer showed me how to sharpen bits on a bench grinder, been doing them that way until recently. no one was talking me into a sharpener when i can do them by hand. i was at my friends shop, and we had a gearcase with 30 broken grade 8 bolts. we started with new cobalt bits, they dulled quickly, sharpening them by hand was difficult. we got a Drill Doctor, and they sharpened like new quickly. that job paid for it. anyone doing much drilling needs one of these.