[crane550]

I have an NPN proximity sensor that I use for homing and limit switches. One sensor per axis, and "triggers" on both end, so the sensor moves with the table.

This has been working great for about a year, but just recently when I hit "Reference All Home" my machine hits the sensor and says I ran into a limit rather then jogging back slightly and setting that Axis to 0. I will over-ride, back off a bit, and try again. Sometimes it will work and I can set my home, and sometimes I have to reset and move the table back off of the switch.

Anyone have this problem before, and can anything be done about it?

[ger21]

Not sure if it's the same with proximity sensors, but the usual cause of this is noise triggering the switch after it backs off. You could try increasing the debounce setting a little and see if it helps.

[Nephi]

I had this exact same problem with a Hurco. I had to take off the way cover and clean the limit switches. It usually had thick layer of oil buildup or a chip on the end of the limit switch, which caused it to trigger prematurely. This always solved the problem for me.

[neilw20]

Mine gets blown out with air on a regular basis. That stops it triggering early.