Reply To: Measuring RPMs…

[david pierce]

Tom,
I think Starret introduced that tool before electricity was invented. I always saw it in their catalog but never knew anyone who bought one. Also, I never knew or heard of a machinist who gauged the cutter speed that way. Even on the CNC equipment the final feeds and speeds were determined by the way the chips looked , the way the part behaved while being cut and the way the part looked when it was finished. In the pivot cutting video you provided a link for, did you notice how slowly the spindle was turning. That RPM was set through experience and learning from previous failures.
david