[mklotz70]

Follow up to my last reply.

Mach 3 is sending 8.3 - 9.4 volts DC to the VFD when I have commanded 6000rpm in Mach3, It definitely fluctuates. . This may be a Mach 3 or possibly a ESS smooth stepper issue/setting. Not sure where to go from here, but I can get the full 6000 RPMs if I control the VFD myself.

Sorry for the delay.....I don't seem to get notifications for new comments, just the original. I have to come back and look for them.

That's great that it's been narrowed down a bit. I don't know mach that well. I'll have to dig around a bit when I have the mill fired up. I've never had any issues with my smooth stepper, but I don't know why mach would vary.

Just to make sure.......the varying voltage at 6000rpms is when you have just the spindle turning at that rpm....correct? You're not measuring that while it's running the toolpath. If that voltage is varying when you simply tell mach to run the spindle at 6000, it should not be. There would be one command sent when you hit F3 or click in mach. Mach won't be sending constantly changing commands, so my guess is that it's not mach. If I remember right, there is an adjustment on the bob to make sure the 10v equals 6000rpms. There's no reason for it to be varying the voltage unless it's possibly bad and the vibrations are causing it to change. It's a small blue component with a screw. You can turn that back and forth a bit to see if it varies the voltage. It should be the adjustment that would raise your 5400 to 6000.....but it shouldn't cause the bouncing of the rpms.