slave axis stepper motor reverse when running

I have a router with two stepper motors on the gantry, it was running ok but suddenly one of the stepper motor reverse it's direction, so they stalled because the gantry became unsquare, i turned it off and start again but still the same fail, does any body knows what could be happen with this problem?

thanks in advance


Noel

This may be a control software issue. What software are you using to run your machine. In Mach4 there is the option to reverse the motor rotation in the motor setup.