RE: [CAD_CAM_EDM_DRO] Adequate torque from VFD driven motors?

In two words - feedback control. If you were to simply drive your motor by a
variable voltage source, you would be correct. But, if you monitored
something (for example, motor speed or back emf of the motor) and adjusted
the voltage to hold the motor speed constant, you'd find that your torque
would improve.

-- Jerry

|But VFD's have been recommended on this list, and most new commercial
|CNC machines seem to control spindle speed this way. So how can this
|be?
|I am retrofitting a lathe that had an elaborate mechanical variable
|speed drive, and it would a lot easier to go the VFD route, especially
|so CSS could be implemented. But I just don't see how there could not
|be a lack of power at lower speeds. What am I missing?