Frank Campbell wrote:
I have never understood the logic of a Drill Doctor for the average
handy man, for the price of the machine a guy can buy a lot of drill
bits.


When I'm working and come across a dull bit, I sharpen it and I'm back
to work in less than a few minutes. If I had to go out and replace the
bit, it would mean a trip to the store. Now, if you do any drilling in
metal, you'd need to buy several bits per project. It might take a
while to recoup the cost of the Drill Doctor, but over a year or two
the machine would pay for itself.

Another downside to replacing bits when they get dull is that you'd be
more likely to keep using a marginal bit until you get out to the store
- whereas with a DD, you can always use a _sharp_ bit every time. It
makes a big difference.