[psch3]

Hello I just bought a grizzly G0602 10x22 lathe. I have it set up and changing spindle speeds is a real pain with the belt setup. I would like to replace the motor and make it variable speed. It comes with a 110v 1hp motor. I have 110v and 220v single faze in my garage. Ive searched this forum about different motors but theres so much information my brain started running out my ears. I would like to know what would be the best motor choice and why. A 3 phase motor and VFD, or a DC motor and SCR drive ? I need an RPM range from 150 to 2500. I do have a 2.6 HP @130v DC treadmill motor. What would be better to use for a spindle motor AC or DC and why? What about torque and HP drop off at lower RPMs? Thanks for any help or advice the more I search this forum on motor choices the more confused I get.

[Al_The_Man]

Generally a DC motor has maximum torque at zero rpm and tapers down slightly at the max rated rpm.
HP is dependent on rpm.
If you already have a decent DC motor, one of the KB or Baldor SCR drives should work, also improved rpm control can be obtained if the motor has a tach, as most of the SCR drives mentioned have the ability to input a tach.
Al.

[psch3]

Thank you Al the Man. I will go with the DC motor. Is there anywhere I can get information about the difference in motor choices and when you would choose them?
DC motor with SCR drive.
AC motor with VFD.

[Al_The_Man]

I dont know of any site that does a comparison, but in general, any motor other than stepper has to have some kind of feed back to accurately control rpm, whether by simple monitoring current or as in a VFD by sensorless vector, the VFD without pulse generator or encoder loses accurate control at lower rpm.
I have used DC servo's as spindle motors as they generally have tach feed back on them which gives accurate control down to really low rpm.
Al.