[fburtt]

I am having trouble with the z limit switch shutting down my 2001 Haas Mini Mill when roughing with an indexable end mill in aluminum.

I'm taking a fairly light cut for the 1" dia tool, .20" axial x .25" radial depth of cut, at 6000 rpm, at 15 inch/min.

The load meter only gets to about 30% when the machine alarms.

Tracked the issue to the z limit switch by tapping on it with a wrench while the spindle was running, which threw the same alarm and stopped the machine.

I replaced the switch with a new one from Haas, and apparently re-installed the same problem. Arrgh.

It's maybe a bit less sensitive, got a little further into the cut before alarming out. But tapping the switch body, or the plate it mounts to, still kills the machine.

Anybody have any experience with this nonsense? I'm ready to fab in a better(?) switch or a prox sensor.

Meanwhile, no spindle time/$$$$...

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It's a HAAS Mini mill

[hfjbuis]

I am having trouble with the z limit switch shutting down my 2001 Haas Mini Mill when roughing with an indexable end mill in aluminum.
Tracked the issue to the z limit switch by tapping on it with a wrench while the spindle was running, which threw the same alarm and stopped the machine.
It's a HAAS Mini mill

If your limit switches are mechanical, then maybe you can activate a digital filter in the controller to prevent reacting on glitches.

I use proximity switches, cheap ebay versions. They are not sensitive to vibration but to electric interference. They worked flawless on the mini lathe, but couldn't get them working on the small lathe. Every time I switched on/off the small lathe motor, the sensor tripped. The final solution was to activate debouncing in the controller. Now they work very well and reliable.

proximity switches I use:
NJK-5002C, NJK-5001C, LJ12A3-4-Z, TL-W5MC1