Quote Originally Posted by dazp1976 View Post
One for Jazz.
Got my PM25 clone running today and works brilliant but...
I used overkill Nema34 (the grief of my X2 knocked me a bit) seem good motors so that's all fine.

Anyway. If I hit my soft limits at 2000mm/min the motors slightly over travel and put my position out by 0.2mm.
I would say this is down to the rotor inertia of the overkill motors. Would you agree?

Simple solution... Don't hit the limits
I do have some decent nema23 size for it. I'll make some mounts so I can try them out.
Soft limits shouldn't be out by any amount. The point of them is that the controller controls the velocity/acceleration and position so it doesn't let you go past the soft limit value and brings the axis to a controlled stop, unlike when you hit a physical limit switch which just turns off the motor output. In this case, you always get over travel from inertia if moving quickly and even at lower feeds you should consider position lost if you hit the E-stop or limit sw.