consew CSM-550-1 motor issue

[Dave38]

Has anyone had an issue with the consew CSM-550-1 motor running at full speed no matter the setting of the pot? Mine was fine to center drill a hole....then 1 minute later went to finish drilling it and it's at full 3000+ rpms with no adjustment. I did check the pot with an ohm meter and it and the wire/connector are fine. Any help is appreciated.
Thanks,
Dave

 

[DeeDeeCues]

Has anyone had an issue with the consew CSM-550-1 motor running at full speed no matter the setting of the pot? Mine was fine to center drill a hole....then 1 minute later went to finish drilling it and it's at full 3000+ rpms with no adjustment. I did check the pot with an ohm meter and it and the wire/connector are fine. Any help is appreciated.
Thanks,
Dave

The motor controller is likely bad. I believe those use pulse-width-modulation (PWM) to control speed with high torque. The knob is not exactly a potentiometer (or if it is, it controls other circuitry and not the motor directly). PWM controllers require more than a voltmeter to troubleshoot.