Ryan,
I think the ShopSabre machine is servo, right? And the Z is probably ballscrew. You say when this happens you have to power everything down and restart it. That sounds like your drive is tripping out.
It sounds like the head is falling. That probably couldn't happen if the drive was holding. If it happens again, try turning the ballscrew with your fingers (up or down) if you can turn it, the motor isn't holding.
If that's the case, I'd start looking for some reason for the fault. The drives are designed to trip if they come against something that will not allow movement. It helps to keep them from being damaged. I would check for binding, or the head coming in contact with something when it reaches the top. I would think that there would be a high limit switch to stop it from going too high, but maybe it's not working or something.
Just a few thoughts.
Butterknife |