440 x-axis continues to jog, won't reference

[ProperWood]

Hello

I own a 440 and have run into this problem before, but the usual solution isn't working now. When referencing the x-axis, the limit switch engages but doesn't stop the table like usual. The motor continues to run and the DRO shows the x-axis position just going and going with no end. The solution in the past has been to move one of the limits to a place where the table wants it to be, not working now. Any suggestions?

thanks

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[ProperWood]

Also, it comes with status messages like "program exceeds machine minimum on x-axis by: 74 inches"

[ProperWood]

Turns out the X limit switch isn't firing - so the new question is, any suggestions on how to troubleshoot a faulty limit switch?

[dannirr]

Get a new one from them

[Doug Darby]

When you trip the switch manually did the light on the status page illuminate?

[GLCarlson]

Get a new one from them

Yep. If it's the microswitch innards, that's a replace, not a repair.

Or build an optical switch
http://www.cnczone.com/forums/tormac...pathpilot.html

[ProperWood]

Thank you for the responses. It was a gunked up limit switch, now I just manually check to see if it's firing before referencing the x-axis. Sometimes it takes pressing it a few times but is working for now.

[CountrySmith]

Hello

I own a 440 and have run into this problem before, but the usual solution isn't working now. When referencing the x-axis, the limit switch engages but doesn't stop the table like usual. The motor continues to run and the DRO shows the x-axis position just going and going with no end. The solution in the past has been to move one of the limits to a place where the table wants it to be, not working now. Any suggestions?

thanks

If you exceed the limit switch position you should be hitting a hard stop at the end of travel. If your motor continues to run, you are most likely slipping somewhere, I would check the motor coupling. It sounds like you have a problem switch and it should be replaced ASAP, It isn't good for the machine to be running into a hard stop. It stresses the entire drive train.

Regarding optical limit switching, I installed optical homing on my 770. I retained the OEM limit switches but with the optical homing and PP's soft limits, I never hit the OEM switches any more. Details are in another thread on this forum.

[cncoperator]

It isn't good for the machine to be running into a hard stop. It stresses the entire drive train..

I have a different view of running a stepper motor into a hard stop. If the mechanics are robust enough, and the Tormach is, a hard stop will do no damage even after multiple stops. On some (all?) machines Tormach uses a resilient doughnut on the screw to moderate an axis deceleration when a limit switch fails.