After putting my machine electronics into a new enclosure I am having trouble with my y axis stepper. When it sits for awhile turned on and then I start to run it it will bind up and make grinding noises. If its attached to the axis it will actually bind and jerk the axis. I thought it might be something on the ballscrews or ways but when i remove the stepper it will actually grind and jerk all by itself. Any suggestions. Thx

What have you tried so far?

What I would do if in this situation would be to wire another known good motor to the drive. If the motor did the same then there would be a problem with the drive; if all was ok then you have a bad motor.

John