Please refer to my old, original thread:
http://www.cnczone.com/forums/showthread.php?t=45025
Since then, I've had the 4th axis working normally most of the time.
Notice I say 'most of the time'. I would spuriously get odd errors on it; Following errors, a motor faults, z faults, etc. Then it would work fine for a week, then have fits.
Along with these crazy and sporadic problems, there's other electrical gremlins; The machine will change spindle speeds by itself, will come off feed hold by itself, and rapid and feeds will decrease without the buttons being touched. I've replaced the keypad to try to take care of that, to no avail. This thing just plain acts weird.
You'll be ten feet away from it and hear 'beep' and the rapid has dropped 10% or the spindle has dropped 10%. Doesn't seem to be temperature or vibration related and I can't find one common thread as to what might be causing these sporadic problems.
The thing that is frankly angering me at this point is that it won't just break and stay broken; I can't troubleshoot it because it will start working normally again. This past run, the axis errors are semi-permanent; I've had the axis off the machine and back on and it's still not working correctly.
I'm at a loss here. Any input is appreciated. Even the techs at the HFO can't seem to give me any advice. I'm at my wits end.