LIMIT SWITCH HIT...LOSING STEPS!

[sevans]

Hello Everyone. Lately my Shopbot (PRS Standard) has been hitting proximity switches in random places on the table. The lights do not go off and it's not even close to the sensors. There is no rhyme or reason to where this happens. At first I just hit resume, and file would finish fine. Now when I hit Resume, it loses steps - loud grinding noise when it resumes and then goes down the table about 5 inches and resumes. This problem seems to be getting worse the more time goes by. Also lately I've been getting missin comm return error - ONLY WHEN ZEROING THE Z AXIS TO PLATE. It goes down for the 1st time, and before it hits the plate I get the error. It must be restarted to resolve the problem. The only thing I've done differently in my shop in the past year is re-ground dust collection system. Any thoughts or sympathy? Thanks so much for you time. -S. Evans

[khaos]

Try connecting your computer and controller to a UPS. This will filter the AC power. I had the proxy ghosts on mine until I did this.

[gerald_martin]

Sarah:

Try some "air cutting" with your spindle or router not running - see if you ever get the prox switch issue. Electrical "noise" from the router or spindle may be the problem...

I know from experience these issues require patience to track down but it can be done. My machine had a similar issue that finally was resolved by installing prox sensors with shielded and grounded cables.

I suggest calling tech support, as they have a lot of experience with this particular problem and they can help you isolate it.

Gerald

[jerry_stanek]

I had this happen last week and found it was a loose sensor wire.