Post By angelw
Need help on single block/ Fanuc OM
The single block is active(light on) at all time(even when the toggle switch is in OFF position) on this Kitamura Mycenter 1 845 with Fanuc OM control( the machine only runs one block at a time in automatic mode.). I took out and checked the switch with the meter for close(ON) and open(OFF). That is a good working switch. Before re-installing the switch, I turned the power back on and notice that single block light was ON(active?) without the switch in place, and same problem too after putting it back. For getting the machine back to normal working, please advice me what to do. And as always, thanks in advance.
Check your door switches.
In addition to Tony's suggestion, the lubrication system will have either a pressure switch, or a level switch. Many MTB forced the control into single block mode, and often without generating any alarm message, when the lube system lost pressure or was low. Most of these switches I've seen fail safe, that is, if the switch fails, or if the signal or ground wire is cut or disconnected, the control sees that as a low lube event.
Originally Posted by tt12no
I second the low oil thing. I run a Kitamura Mycenter that does the exact same thing.
Need help on single block/ Fanuc OM
Total agreement with the Low Lube solution.
I just got through training a shop in Chicago with exactly the same problem on a used mill with the Fanuc 0M control.
We took the switch apart, checked the door interlocks, the switch wa stuck no matter what.
Finally a light went on, could it be low lube?
Yes it was !.
Make a note everybody, I'll never forget it.
Oil level was low.
Angelw was right. The oil level was low on this machine. Thanks to everyone' s opions.
Our OKK blasts its alarm horn with a sound that could raise the dead when it runs short on oil.
While not exactly the same thing, this story could help somebody:
A few days back, I was in the middle of a 72 minute cycle on our Haas GR510 router.
Wham! Machine screeches to a halt.
Will not restart (Alarm: Emergency switch pressed)
It turns out that the power supply to the vacuum table had become disconnected and is interlocked with the control, much like the lube fault mentioned above.
Restored power to the table and all was well again.
Got a little Chevalier Cat 40 VMC with the Fanuc Oi-MB control. Did the exact same thing, lube level got low, single block activated. Took a service call all the way out from Houston to find that they do that when the lube gets low. 3 and 1/2 hours of drive time in that service call. Thing that really aggravated me was the fact that the books said not one word about it. Actually I thought the switch had gone bad and had them order one before they came all that way out here. Then when the tech got here, he takes one look at it, and asks if the lube is low. If the books had mentioned it, I would have checked that first.
Originally Posted by Heinz R. Putz
We of course do periodic maintenance and would have caught it next time through, but a line behind the table, under the shields, had burst, making it use an excessive amount of lube all of a sudden. Not even something I would call a tech to repair in itself, but being colorblind, I usually bring in a tech on electrical problems. Cross up a green wire and a red wire and sometimes it gets damned expensive. Sorta like having a tech drive half a day to tell you that the lube is low gets expensive.
That's my main objection to service manuals. They always seem to have something in there that expects you to already know something. If I knew everything, why would I be looking in the service manual? And it's a common failing through all brands. I've been through Fanucs, Fagors, and Okumas, they all have the same problem. there will be some minor detail that they leave out completely, not even alluding to it at all. But without that detail, your looking at Chinese arithmetic. Or Greek, suit yourself as to what flavor.
Not to bump an old thread but this info really saved me a lot anguish and wasted time. I thought I had a bad switch also and was starting to look into disabling single block in the control instead of opening up old delicate electronics. In my case it was activated because I lost air pressure so that is what obviously triggered the lube system to complain. I would have thought I would have gotten a regular alarm and didn't find anything about it in the manual. I am just barely 10 hours hands on with a "real" control and it happens to be a Fanuc 0MB, which I gather isn't the most newb friendly to begin with, and I went from "Grrrr" to "Whewww" pretty quickly thanks to this wisdom. I was just about to post a topic but I figured I would try a different search phrase and of course my answer was already on here.
I've always felt this was kind of a "ghetto" method of letting the operator know their lube level or air pressure was low. I always wondered about it when it is not that much more complicated in the ladder program to generate an error message on the alarm page. I have always preferred that low lube level alarms generate a message but allow the current cycle to complete either to an M30, M0, or M1 and inhibit the Cycle Start until the tank is filled.
BTW, the behavior of a machine for this type of issue is not a function of the Fanuc control. It is entirely up to the machine tool builder how to handle the situation.
Last edited by Vancbiker; 06-17-2014 at 12:58 PM.
Reason: added content