Hello,
I have a homemade cnc router. It has three pacific scientific motors and drivers on it. The problem I am having is as follows: as the machine runs a program, the motors will lock up and start to hum. It usually happens when the z axis completes a movement and the x and y start to move.

I keep thinking that my power supply is not keeping up with the demand but it seems to happen no matter what speed I run the motors. I have had them as low as 200 mm per minute and they still do it. It happens randomly during a program run and does it on almost every program I try.

Any help is appreciated,