Mike(?)
The 912 developed a dreadful grinding noise on the uplift of the z axis, and I guess the added friction fooled the controller into thinking the spindle wasn't where it was supposed to be, so sometimes it wouldn't even touch the job and sometimes it drove itself right through it. I thought it might be the linear bearings, but after I replaced them (lucky find on eBay!) no luck. I took the motor down to a local repair shop and they wouldn't even touch it, so I took it apart and cleaned and it turned more freely, but still didn't work properly. So, I think it's the motor. It's a Vexta PH268-21 by Oriental motors and it's not made anymore. I'd love to get it up and running again because it really is a great little machine, so, let me know if you think there's some hope for it.
Ian

Ian,

If thats a Pro-Am 912 I might be able to tell you where to get a new motor. After mine started having problems I found places to buy parts and the motors are on my parts list that I found if I needed them to be replaced.

Puck

Ian,

I have several of those motors, I might question if that was the problem to begin with. It is very possible that the driver control board or the power supply is what caused the problem in the beginning.

However once the stepper motor has been taken apart it is done it will never work properly again. You will need to replace the motor and then see if it was the motor driver or power supply that actually caused the problem.

It is not a common item to fail on these engravers I would not say it is not possible but with my experience it usually is caused by the controller.