[LEARN]

I have a IH cnc that has been having some fluctuation in the spindle . it sounds as if it just is starving for power to the motor . it still cuts good but the spindle speed drops off here and there.

Any thoughts ?

[SCzEngrgGroup]

Probably either a software problem on the PC, or a problem with your BOB. You need to look at the analog control voltage output by the BOB that tells the VFD what speed to go. If that is varying, then either the PWM output from the PC is not consistent, or the PWM-to-voltage converter on the BOB is flaky. Otherwise, could be a problem with the VFD itself, but I doubt that is the case.

Regards,
Ray L.

[LEARN]

Bob?

[SCzEngrgGroup]

BOB = Breakout Board - the interface between the computer and the motor drivers, spindle controls, etc. You'll want to have a wiring diagram for the machine....

BTW - You're more likely to get help in the IH forum.

Regards,
Ray L.

[LEARN]

Thanks . I did not want to post it there due to the fact it's not a factory build if that makes since

[LEARN]

Thanks . I did not want to post it there due to the fact it's not a factory build if that makes since