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1993 Makino FNC60 VMC with Fanuc OM-C...boots up with alarm but can't figure out why

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First off, machine has run fine for months, but last time I ran it was about 10 days ago. Only difference in then and now is 20 degree drop in shop temperature.

Turn on main electrical, all seems fine, turn on control all seems fine...but then it stops right before it normally would turn on servos and red alarm light appears upper left of control face (to left of low oil light) and get "not ready" blinking.

1. No message at alarm messages
2. E stops out
3. Air good (although not needed to boot up anyway really)
4. Everything looks normal in electrical cabinet...LED lights on each module lit, spindle drive LED's lit (power on and speed indicator), no circuit breakers tripped.
5. Parameters and programs seem intact (fresh backup batteries about two months ago as well)
6. Spindle chiller is on and working

Any ideas ?

Milacron
 
Is there a sensor for low lube in the oil resevior? Bulb out in the low lube light? Not sitting on a limit switch?
I mentioned the low oil level light partially to indicate there is a seperate light just for low oil levels...so that is not it. And no, not on limit switch.

Since posting initial post, I found info about that alarm light in the Makino manual, and it seems to be concerned specifically with the spindle motor or drive. It says (typed in Singaporeish just as in manual :rolleyes5:)

The alarm lamp comes on in case of spindle drive motor trouble, thermal overload & the machine emergency is stopped. To reset the alarm, replace the spindle drive unit fuse in the machine control panel reset thermal overload and/or turn the reset switch on & then press the NC reset key.

Sounds easy, right ? Well of course there is no thermal overload that I can find. Hidden deep inside the spindle drive are three glass fuses...but they are ok. Spindle drive seems to be fine. So unless there is a secret thermal overload somewhere I suspect the problem is somewhere on the CNC boards. Seems like if there was thermal overload that was tripped the spindle drive wouldn't come on at all...but it does seem to come on just fine. Maddening there is no alarm number.

Milacron
 
Is this the same FNC 60 as before? I get that red alarm light when I overload the spindle motor. For example I put too much cut into my face mill in SST a short while ago and the machine stalls, flashes "alarm" and the red light comes on. The only way I can recover from this is to totally power down. Control off, and then the main cabinet. I usually walk away a few minutes and then come back to reboot. Then the error is cleared. I know this helps you in no way other then to say that it sounds like the same symptoms as overloaded spindle drive. At least it might help you to know where to look. I wonder if there are flashing lights on my spindle drive when I overload it.
 
Is this the same FNC 60 as before? I get that red alarm light when I overload the spindle motor. For example I put too much cut into my face mill in SST a short while ago and the machine stalls, flashes "alarm" and the red light comes on. The only way I can recover from this is to totally power down. Control off, and then the main cabinet. I usually walk away a few minutes and then come back to reboot. Then the error is cleared. I know this helps you in no way other then to say that it sounds like the same symptoms as overloaded spindle drive. At least it might help you to know where to look. I wonder if there are flashing lights on my spindle drive when I overload it.
Sounds like your red alarm light is working like it is supposed to, whereas mine has gone haywire. I've never even cut anything with the machine, much less overloaded it. And total powerdown does nothing to help in my case.

Still I wonder if there is a secret thermal overload that has gone crazy that I could deal with ? Worst case senario would be that whatever in the CNC that deals with that reset has gone nutty. I sure have a knack for getting some of the most complex electronic problems imaginable sometimes

Milacron :o
 
I don't know about this machine, but some spindle motors have temp sensors inside. I would check out the cables to the motor and see if you can find a way to electrically check (maybe resistance?) the sensor (assuming it has one).
 
Based on the age, I assume the spindle drive and motor are AC. So, it won't have a thermal overload, and that's why you didn't find one. You mention the "speed indicator" on the drive, so I'm going to guess that's the 5-digit display. If the drive had an alarm, this wouldn't show. Instead, it would show AL-12, or similar, for the 5 digits. I suspect the drive is fine. It sounds like the E-stop chain is broken, so measuring end-to-end with a meter will show if this is the case. The chain will be found in the electric diagram (schematic), more to the front. This is a process of elimination, finding one signal at a time in that chain to see if it is open or closed. Keep in mind the E-stop chain signals will be normally-closed, so that any one of them opening will stop the machine.
 
I don know if I have any helpful input for troubleshooting, except to say I will be in front of my machine ('91 FNC-60) this weekend, and would be happy to take photos or do simple diagnostics for comparison, if it would help. I will say that my machine also displays the same "not ready" when the control is started with the e-stop depressed. I will check this weekend if the alarm light also goes on in that state. I do not remember right now.
 
My Matsuura does something simaler if its sat for awhile,in my case it is the T/C arm has dropped off the limit, I must climb up top with a pencil and manually function a silanode(sp,?)
Gw
 
Based on the age, I assume the spindle drive and motor are AC. So, it won't have a thermal overload, and that's why you didn't find one. You mention the "speed indicator" on the drive, so I'm going to guess that's the 5-digit display. If the drive had an alarm, this wouldn't show. Instead, it would show AL-12, or similar, for the 5 digits.
Right, red cap Fanuc AC motors for spindle and axis, and the spindle drive 5 digit display is all zeros, just as one would expect on a good drive in idle mode.
 
Don, as the light indicates a specific issue that is a good place to start, however it may not be the problem. While the alarm I got on my Fanuc machine is different than yours, I was also getting a alarm on start up. The actual alarm I got isnt important as it was just because there was an error during machine start up when a relay failed to close. This caused the spindle amp not to start up correctly so the machine read out a spindle fault.

Took me a long time to sort out the relay as it was an intermittent problem. It wound up that the relay had power but was not shifting state. When I start my machine I know now to listen for two relays to close and that lets me know the startup completed properly. You probably havent had your machine long enough to get used to what it does on startup but I would try to go through the logical procedure and check each relay for proper outputs. But then I know you know that already...sorry this may not be much help to you.

Charles
 
OK. I fired up my identical mill without the spindle chiller on and it behaves just like yours. Red light is on, displays not ready like the estop circuit is broken. This seems more likely to me then the spindle motor or drive since they are all coming up without errors. Logically I am thinking that if the spindle chiller is not turned on that the machine breaks the estop chain and sets the red light alarm signal. Then the machine won't be operable until the spindle chiller is addressed. I know you said your spindle chiller is on, I just think that this is the place to be looking. Fiddling with the thermostat, maybe removing the cover and looking for loose connections. Sounds like the input that says the chiller is on isn't making it to the control. Hope this helps.
-Greg
 
OK. I fired up my identical mill without the spindle chiller on and it behaves just like yours. Red light is on, displays not ready like the estop circuit is broken. This seems more likely to me then the spindle motor or drive since they are all coming up without errors. Logically I am thinking that if the spindle chiller is not turned on that the machine breaks the estop chain and sets the red light alarm signal. Then the machine won't be operable until the spindle chiller is addressed. I know you said your spindle chiller is on, I just think that this is the place to be looking. Fiddling with the thermostat, maybe removing the cover and looking for loose connections. Sounds like the input that says the chiller is on isn't making it to the control. Hope this helps.
-Greg
Ah, very interesting Greg....hopefully I'll get to shop later today to check that out.
 
Didn't get back to work on the Makino until this afternoon. After pressing some buttons at the tool changer station, magically the machine came alive and was working again. So I ran a program, it changed tools just fine the first time...but the second time it hung up with the swivel arm in swiveled position holding both tools. There is a proceedure via changing two diagnostic parameters to manually get the tool arm back to normal position....which was on the verge of working when the darn thing went into E stop mode again and this time won't come out.

So, all I can figure is either something buggy going on with one of the tool arm limit switches, or something not quite right with the E stop button or one of the other buttons at the tool changer. I presume I can get the tool arm back manually by removing some sheet metal to access the tool arm motor and turning it by hand...oh what fun lies ahead :fight:

Milacron
 
Turns out moving the tool change arm back was really easy....turn a set of gears with screwdriver pryed in between, no big deal. Same motor/gears moves the carosel tool back up at the same time. I was completely wrong on the buttons or limit switch theory...they are all fine.

But pretty sure I fixed the machine....will wait to run some more programs on Monday before I claim total victory and will post then regarding the solution.
 
I had a similar problem with my toolchanger when it got hung up, after reading the instructions in the Fanuc book it says to push one button on the panel and then another one. However nothing happened, so I tried the procedure again and again and still it wouldnt work. Finally someone told me to hold the first button down while jogging with the second button, and magically it worked fine. One more example of the lovely Japanese to English translation of the manuals.

Charles
 
Well, it ran great again today...until I encountered a new problem...will start a new thread on that one as it's so different. But the cure for the alarm "not ready" issue was to Stabilant treat and reseat all the socketed IC's. I had tried that first thing with no results, but after testing so many other possiblties and finding nothing wrong, got desperate enough to look a bit harder for IC's I might have missed and sure enough found a few on the motherboard that were almost hidden from view. Reseated those and that did the trick.
 








 
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