Hello!

My issue is my axis loses steps, mostly on the Z axis, but also sometimes on Y. The Z axis will lift to move to another position, and loose its position, so that next time it lowers into the material it is no longer at correct depth. Also, I notice that when I click reset on MACH 3,. my axis all lurch maybe half an inch away from soft limit settings, even after zeroing the machine coords.

I have had this problem intermittently for some time now, and have tried many things.
I have the controller box and computer on separate dedicated breakers.
I have all pieces grounded- computer, controller, table, gantry, and Z axis- to a common ground point.
I just replaced the Z axis with a new linear bearing/ball screw rated for 100lb vertical load.

My system uses Mach3, and individual Gecko drives controlled by a Dell PC with a parallel port that has no internet connection at all.

Right now, I can't rely on the machine to cut for 10 minutes without error.

I'm now considering these potential causes:
1) connections/cabling
2) heat in controller on Gecko drive modules
3) issues with parallel port

My questions- how do I troubleshoot this? What would you recommend as a next step.

Thank you!