Well for now I'll wait untill others chime in to give me there feedback.


Thanks for your input.

Frank, have you visually reviewed the bits that did not sharpen well to see if the sharpening wasn't complete, or the grind angle off? Any other possible failure modes?

In other words, do you know what is or is not happening when your sharpening isn't working?

In the cases here where the larger bits did not sharpen, many times a review of the tip indicated that for one reason or another, the grind angle was off. Most times it was off severely enough that the cutting edge was literally lower than the following shoulder, meaning that the bit could never cut.

My experiences have led me to believe that one of the following two things occurs when there is a problem. One possibility is that the larger diameter bits do not have the same twist rate as smaller diameter bits do. Since your sharpening alignment is totally dependent on locating off the center rib, that means that any twist rate difference affects the cut angle and orientation.

The second possibility also hinges on twist rate, but in this case, I've noticed that some bits do have a different twist rate than others. Same problem as above.

I found that number of turns can vary. Some bits I pulled out needed to be re aligned and sharpened again. This seemed to be from not quite being sharp and looking at the pictures supplied.

Well maybe I need to make several more attempts at sharpening a couple more bits. I'll keep you posted.

The reason I've had so many dull bits is because for years I've been drilling through stainless and let me say that they're hard on drill bits, especially hole saws. I used to use a greenlee hole punch but it got stolen.

I prefer doing it by hand on a bench grinder or surface grinder. I'm not perfect at sharpening drills and other tooling by hand but I'm getting better. The drill doctor is a waste of money, if you really have that many tools to sharpen practice by hand.
First rule of thumb being keep the tool cool, don't let the material blue or turn straw colored while sharpening.

Ed

Unfortunatly I don't have anyone close to me that can teach me how to do it by hand. Therefore in trying to be consistent, I figured the Drill Doctor could fit that bill.

Frank...hang in for a whle and next time we get together we'll do a drill sharpening thing. (wink wink) everyone gets a turn and we'll get it figured out.

Deal, I'l even bring about 100 worn drill bits to use as a test sample.