Lathe Home Question

[Grindsmygears]

On our Lathe when I try to home it it doesn't stop moving on the x axis till I get an error message saying "cant find home" this started all of a sudden. never had that problem before. it will hit the limit switch and then move away till I get that error message.

[cncsnw]

Sounds like either a stuck switch or a failed encoder.

If the switch sticks (does not close reliably as soon as the axis moves off it) the axis will keep moving away indefinitely. You can watch the switch on the PLC Diagnostic display (Alt-i). See if it stays red for more than a fraction of a second. Try cleaning the switch with electronic contact cleaner.

If the control never sees the encoder index pulse, you could have a variety of homing problems. The response has varied with different software and hardware versions. Go to the PID Configuration screen and watch the for an asterisk ("*") to appear next to the axis label ("X") in the lower left of the screen while you slowly turn the motor back and forth one revolution. The asterisk will flash very briefly as the encoder index comes around. It should appear in one place, and only one place, in every revolution of the motor.