I have just changed the motion controller on my cnc router from usb smoothstepper to UC400ETH and now the precision is horrible. It seems like for some reason I'm losing steps with the UC400ETH. The only change made to the system is choosing a different motion controller in Mach3 and installing the UC400. What can possibly be different in the UC400ETH compared with the usb SS making it behave like this?? I have also tried a UC100...same problem.
I'm running Mach3 -> UC400ETH -> G540 -> some china motors.