Switch problem,
Eric,
Do you think it's purely an electronic problem, like strong (electro) magnetical induction in cables, or is it a vibration in the construction that might not be detected by touch or hearing. That could allso trigger a switch. Only one occurance would halt the software as well.
With an oscilloscope you could try to find irregularities in the signals. The ferrite ring was the first most obvious thing to try. Would it be a good idea to ground your machine to a clean earth? Ring shaped constructions could run large induction currents, like your gantry perhaps? You could go for magnetically operated switches like reed relais?
I dont know, it could be a million things, just trying to think my way out of this one
Keep us posted, this could affect more builders.
Good luck...
Ed.
Not the horse, of course of course...
Building my own Scrapheap challenge CNC, or is it Junkyard wars CNC?