[rideredcr]

Machine was built in 2002. I have owned it since 2007. This machine gets lightly used, I probably use it 200 hrs/yr. Today I fired it up like normal and during the homing cycle I noticed the Z axis moving in the incorrect direction. It moves towards the spindle. I have opened up the back cabinet, breakers don't seem to be the issue and I do not see any faults or blinking lights. I've tried shutting it down and restarting it after 5 min many times. The Z-axis limit switch is mechanically working properly. Any Ideas what the issue could be? Here is a video.

20150126 190240 - YouTube

[haastec]

The Z-axis limit switch is mechanically working properly. Any Ideas what the issue could be?

It's working mechanically, but is it working electrically? Meaning can you see it change states in diagnostics?
The issue you are describing typically points to a faulty switch.

[rideredcr]

It's working mechanically, but is it working electrically? Meaning can you see it change states in diagnostics?
The issue you are describing typically points to a faulty switch.

Thank you for your quick response haastec. I will verify if the z axis limit switch is working electrically and post my results.

[andre_77]

I had this problem was when getting chips on the sensor zero position z.

[rideredcr]

I had this problem was when getting chips on the sensor zero position z.

Haastec was correct. It was the Z - axis limit switch. The switch had high resistance. Further inspection showed coolant had seeped down inside it. With as much coolant drained out of switch as possible (it is a solid molded switch), the lathe functions properly now. Big thank you to Haastec