Has anyone come up with a good way to increase the RPMS on a round column mill / drill. I use mine almost exclusively for aluminum and would like to cnc it, but thinking higher RPMs would be nice to use smaller end mills with it efficiently. Max RPMs I believe are around 2500 RPMS stock.

Any ideas?

Thank you

Dan

I don't ahve the answer for you, but I wanted to subscribe to this thread to see what kind of answers you get, as I would also be interested in increasing the speed of the spindle on my mill drill. I have been considering building a secondary air driven spindle that could be quickly clamped and un-clamped from the quill on my machine to be used when high RPM's are needed for small bits in plastic.

If your motor is of the 1725rpm variety, you can replace it with a 3450rpm motor. This should double the spindle speed to 5000 rpm. Note that your torque will be reduced significantly when you use your larger cutters like face mills and boring heads.

A better idea is to get another 1725rpm motor, but a 3-phase version. Use a VFD as both a phase converter and a speed controller. You won't lose any torque at the lower RPMs, but you can crank up the frequency to 120HZ (double that of the 60HZ coming out of the wall outlet) and you'll get double the spindle speed.