Servo getting hot, Gecko 320

[carlnpa]

Servo motor is getting pretty hot, drive is a 320, the mechanicals are moving freely. The hot motor is singing alot. The other motors are fine, running cool no issues. I had a fault during a run today, but didn't check which drive it was.
Any ideas on the hot servo?
TIA
carl

[Dennis Bohlke]

Everytime it has been a bad motor for me.

It happens when the motor windings get over amp'd. Make sure your motor supply voltage does not exceed voltage rating of the motor. My mistake was to supply greater voltage than the rated voltage for the motor.

If you disconnect the motor armature wires from the 320, then short them together and physically turn the motor. There should be consistant resistance to manually rotating the motor shaft.

If you have inductance meter you can also measure the armature coil inductance. It should be the same as the motors that are not getting hot. Also it should be consistant for the whole 360 degrees of rotation.

Dennis Bohlke
http://www.super-tech.com

[carlnpa]

Seems I had several different issues that all came together, mechanical and tuning and a problem with both Mach 2 and 3.
It took me awhile to figure this out, I had a table full of partially cut parts with expensive plastic material.
The mechanical, my limit switch was making at a slightly longer throw, the ballnut would kiss the hard stop, fault the gecko, then rebound so it still felt free.
The hot motor was resolved by retuning the motor, it ran cool for 16 months. I am not sure what changed to bring on hot and singing, the Geckos were not touched so maybe a motor wear characteristic.
Mach 2 and 3 absolutely refused to pick up "run from here" where I needed it to in trying to salvage some of the parts. It would pick up from some positions but not the one I needed. Both programs balked at the same spot in run from here but ran fine through the all code otherwise.
I lost the parts.