Machine Malfunction Traced to Small Mammalian Life-Forms

Worth a read for fun: A supposed sensor fault in a CNC device turned out to be caused by an atypical interaction with some rodent incisors.October 26, 2011

Question
I had the sensors go out on me today on one side of my 2004 Biesse Rover B, and usually it's an alignment issue. This time I can't get them on at all. I've even pulled a reflector off and brought it point blank to each individual sensor. Any ideas? Bad cable? I've unplugged and reattached what I could as well as reset the machine itself, and no luck.

Forum Responses
(CNC Forum)
From contributor W:
One time on our Rover 24, before we upgraded to a light curtain, I had to make an L shaped piece of MDF and used that chrome duct tape the whole length to bypass the sensors. You may have two bad ones, so testing each individual sensor may not do it. Use the long strip as mentioned above so you can fool every sensor at once. If it then works, you can rule out a wiring problem, then start sliding the piece back to reveal one sensor at a time until you find the problem one.



From the original questioner:
I don't know a whole lot about the sensors, but if I can't get any of them to light up or if two are bad, how would they all light up at once with this method? I am in the process of trying it, I just wondered.


From contributor W:
I'm not sure. It's been about 7 years since we had those sensor bars on our Rover 24. What I mentioned above would rule out any alignment issues. I can't remember if there's an LED on them to show that they have power on each sensor. I think that's what you're referring to as "lighting up."


From the original questioner:
Yeah, that is what I'm referring to. The LEDs on the sensor won't light up at all. I've checked the power to the panel they're wired into and that is fine. I've checked each sensor for power and that is fine as well. I've swapped out a sensor that works on the other side of the machine and that did not help. I'm stumped.


From contributor W:
I'll check my Rover 24 machine electrical schematics tomorrow at work and see if I can find other test points for you. I'd still check for loose connectors or bad wiring.


From the original questioner:
So I pulled apart the arm that all of the wiring runs through and it turns out a mouse had chewed through part of the cable. Repaired the wires and we're up and running. Thanks for the advice.


From contributor W:
Glad to hear you got it sorted out. My hot tub suffered the same problem in the fall!