Rapid Traverse Possesed?

[spock]

Back in the summer I added a new Sharpe super mini mill to my shop. Fanuc oi-mc control. Everything goes smooth as silk for a few months, then the machine begins to occaisionally rapid traverse at 100% even when the switch is set at 25 0r 50%. (Ruined some shorts!) If I am running a program with a tool change, and it takes off at the "wrong" rapid rate, it will go through the program correctly, feeds will be ok, but it will rapid back to tool change position at 100% and then "hang up" in the tool change macro. I have to reset and restart the program from there.

So I of course called the tech, who promptly came out and looked it over. He thought that the time allowance in the tool change macro wasnt giving the control enough time to scan the ladder for the two signals that it requires to know how fast to go. When it doesnt get both signals, it defaults back to 100% rapid traverse.
made sense to me, so the tech added some more time to the toolchange macro, which seemed to work fine for several weeks. Then, it started doing it again.
My neighbor came buy one day to shoot the bull, and I was telling him about the problem. He suggested that it was the cold making it happen, slowing down the speed of the control like a cold cell phone or computer. I checked the operating temp. range for the machine, I am in it fine. But it does seem to make sense, the mill started acting up when it bagan to cool down in the fall, and now only malfunctions when it is very cold (20 0r so) outside. That brings the shop temps down in the 60's, which still shouldnt be a problem?
Question is, can cold be causing this, and why? Have any of you folks seen anything like this, and how was it remidied?

 

[appliedproto]

Cold causes problems for LCD displays....but it wouldn't affect the performance of the solid-state electronics. When I used to do surveying, I had laptops in sub-zero temperature that ran perfectly fine. Tough on the battery life though

 

[PBMW]

I also have the same machine with a 0iMc control. Never seen anything like that though. The machine did hang once in the T/C macro. I did a reset and moved on and all was fine. I would suspect maybe the rapid over ride switch??? You maybe on to something about sensors and time delays.

 

[Solar71]

Your machine has a problem...

60f is NOT COLD...

Cmon man, You got that machine used or new ?
If new, and if the machine is 5 or less years old, cmon...

Machine has a problem... Not a cold...

 

[HuFlungDung]

Check for bad or loose connections in the I/O from the tool changer. Maybe if you can fix the problem with the hangup (completion or ready signal) from there, the rapids problem will be bypassed.

 

[spock]

Solar, got her new.

Hu, checked with the tech, he now thinks some connection is probably the culprit. Advises me to just leave the machine on all the time till he can come by and check them out. I think that the rapid problem is what is causing the hangup ,though. The only time it hangs is when rapid goes nuts.