Re: [CAD_CAM_EDM_DRO] VFD Positioning?

C.S. Mo wrote:

>Assuming you put an encoder w/Index on your spindle, what kind of
>positional accuracy can you get controlling the spindle with a 'typical'
>VFD (not one of the super accurate ones - but a standard FM50 or FM100 as
>example)?
>
>As in, is it possible to have the spindle turn x degrees? Or can you only
>control RPM?
>
>

You really can't. These are not designed as servo drives, and can't
respond to speed changes at more than a few times a second. You would
certainly be able to keep a spindle within one revolution of the motor,
but it would easily wobble maybe 90 degrees before the CNC could get the
VFD to correct it.

Jon