Karl Townsend wrote:
I'm about to buy a 5 hp. VFD drive for my hardinge CHNC. Looking at
automation direct, I see three categories of drives

Categories L100 Drives (Volts per Hertz ctrl mode)
SJ100 Drives (sensorless vector or V/H ctrl modes)
SJ300 Drives (sensorless or flux vector ctrl modes)

Not knowing squat, I'm tempted to buy the middle price one - SJ100 series.
Correct choice? What's the difference?
Buy the cheap one. You don't need precision positioning, just
rough speed control. The Volts/Hz mode should be fine for
a lathe spindle.

Jon