Here is a cheap
tach that is used in the RC airplane field. I have a similar one that I have used for years, and I was wondering if it could be hacked to feed a signal to a PC.
I am thinking of using a servo to drill/tap holes. Is there any software that could control a dc motor via the tach, or via a standard encoder that would allow me to tap holes with just a tap bit mounted in the chuck? (i.e. no tapmatic head)
Zeph