Sorry chaps, I didn't give all the information - having a bad time at present!
The VFD is for my Bridgeport clone. I have a dual voltage 3-phase AC motor, and a single phase supply to the machine. My intention is to use Mach3 to control the speed, not just on/off/rev, using as you say a spindle controller, I just need to get the right VFD to be able to do this!
Thanks