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Spindle intermittent - Fanuc 11T with FUJI drive

ToolCat

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Spindle intermittent - Fanuc 11T with FUJI drive

Sometimes the spindle starts and sometimes not. No alarms. For testing I mdi s400 m3 and then switch to rapid mode so I can use the spindle on/off buttons. Sometimes it will start but most of the time it won't. Sometimes starts and then stops in a few seconds. In fact a few times if it doesn't start and you just let sit that way for a few minutes it might start on its own. Watching relays the only one that changes when this happens is one called SUP. While in M3 and the spindle is not spinning if the SUP relay is off, and it will be on if the spindle is turning.

I was hoping it would be a bad contact and spent much time removing 70 some relays, cleaning contacts, and ohm checking before reinstalling. Unfortunately that was not it because the machine behaves just the same. Looking through the electrical drawings in the manual to see what turns on the SUP relay. See attachment. Wire 500 and wire 421 I can see on the machine do attach to the coil of the SUP relay. Now trying to follow that wire back. Line 421 connects to the spindle drive through connector CN1(19) I have found that connector on the drive but I do not see 14C 14X or 14A. I wonder if 14X is an IC?

Any ideas? Does this problem even sound like a spindle drive problem? The spindle is fine when it is working.

20200503_110236.jpg
 
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I had an issue like that not long ago. On a Fanuc Om. Spindle would just stop mid program for no reason, and the program would keep running x-y-z axis.
It was intermittent and for a day or so I could not figure it out.
One time it happened I caught an alarm code flash for the ATC for a split second, then it cleared itself.
This gave me the idea to look at tool changer limit switches.
Comparing the diagnostic bits to the ATC home limit switches wiring and logic I was able to find and confirm wiring. Wiggling the wiring bundle make the bit go high/low.
Turned out that the ATC home LS terminal screw was very loose. When I had a heavier cut happening it would vibrate and when the control see an open switch. That stopped the spindle the spindle.
It was actually a perfect troubleshooting session,complete with smoking gun and simple fix.
 
.......I wonder if 14X is an IC?.....

Very unlikely to be an IC. Most likely to be a tiny PCB mounted relay. The SUP relay is probably just using a set of NO contacts to provide an input to the PMC that the spindle is approaching the commanded speed. Most drive systems are set up to turn that signal on when the spindle speed has reached 80% of the commanded speed.

First place to check is that the output from the PMC to the drive is turning on when you command rotation but it does not start. If that signal is on but the spindle doesn't run then you need to verify that the spindle drive is receiving the signal. Bad connection, or broken wire are strong possibilities. Since it is intermittent, I doubt that it is a problem on the drive board. If spindle run signal is off then you have to figure out what in the ladder logic is preventing it turning on despite being commanded on.
 
is this a main spindle or live tool spindle?
My live tool spindle had the exact same thing. hit the button nothing no alarms went on for a year + it was a pain int he ass to figure out. Came on by itself when it wanted too after you hit start. I was working on it one night didnt work said screw it didnt turn the machine off. went home came in the next morning and the spindle was running.
It didnt make any difference if it was in jog mdi etc etc.it had a mind of its own.
I cleaned all the the spindle relays and all other relays close to 40. talking to a tech friend of mine he suggested the relays were worn and or sticky inside.
so I replaced the spindle ones. havent had a problem sense 5 of them for the live tooling.

My machine is a Miyano has 2 fuji drives. the main spindle still has issues but I get a error every once in a while on that one.
 
Thanks for ideas. Good on maybe it is just a bad connection somewhere rather than the drive.

Delw, It does the same exact same behavior with both spindles. Main and live.

Vancbiker, I just now looked at the first few ladder pages. I don't know how to find the output from the PMC to the drive. I scrolled through a few of the first screens, and for each screen turned M3 on and off to see if anything changed. See attachment. On this page both R026.1 and X005.5 light up when M3 turns on and go out with M5. If the spindle did or didn't spin with M3 it was the same with those two lit up.

20200503_163534.jpg
 
When the spindle was running I photographed every diagnostic page. Then when the spindle was not running I pulled up each page and compared to the photographs. The only one that was different was 410 bit #1. From what I read that is turned on when the spindle meets the commanded rpm, so that isn't it. Vmipacman, I wonder if this bit is the SUP relay.
 
Mine did it in foward and reverse.
as well as inching and spindle on in the jog mode. also during program.

one thing to keep an eye on if its the older fuji drives is the 12 volt signal goes out on the drive. and it wont allow you to do a a feed in g96. you wont get an error.
the expensive part is replace/repair the drive as fuji said that means the drive is bad and needs repair. the redneck cheap part is a 10 cent alligator jumper clamp to another 12volt signal on the fuji drive to the relay. its worked for 6-8 years now.

nice thing about fuji drivers they are extremely helpful and have helped me diag. the problem while on the phone with them. if I recall they were in ga or south Carolina.
 
I would do some troubleshooting to try and narrow down what you are looking for. For instance, What corelations can you draw for when it runs to the outside world conditions. Right after startup does it run but after it’s been running a bit will it do this a lot? , if you leave the m3 running can you tap relays, wiggle cables, and get it to come back on?
One telltale for me was that when the spindle stopped the screen would change to the alarm page but no alarm, signaled to me to look in that direction rather than at broken hardware.
It’s probably terribly unsafe but I’d enable a m03 s100 and when it stops, very carefully start wiggling wires and tapping cube relays with the head of a screwdriver. If you are lucky enough to tap or wiggle the right thing it will be real easy to find the problem from there.

I’m not quick at it, but can muddle through ladder and the diagnostic bits if I have to, but over the internet id be worthless. Trial and error is easy and what I would do first.
 
.......I don't know how to find the output from the PMC to the drive. I scrolled through a few of the first screens, and for each screen turned M3 on and off to see if anything changed. See attachment. On this page both R026.1 and X005.5 light up when M3 turns on and go out with M5. If the spindle did or didn't spin with M3 it was the same with those two lit up. ....

Most builders will have that most easily found in their schematic rather than the ladder. At this stage I'm not thinking a look at the ladder is needed. Maybe after more basic troubleshooting has been done.

PMC outputs to the machine are Y addresses. Those can be monitored at the PCDGN screen that will be one of the softkey after you press the NC/PC button. Usually in a wiring diagram from Asian builders there will be Y Addresses on the left side of the page with connections to the devices they drive on the right of the page. Euro builders often draw this with the Y addresses at the top of the page with the connections to the devices at the bottom of the page. How these outputs are labeled is up to the machine builder though lots of Asian builders will use SFR for Spindle FoRward and SRV for Spindle ReVerse.
 
Now this morning the NC/PC button doesn't switch screens. It worked yesterday. I shut it down and with ohm meter checked the NC/PC button from the backside and the button itself works. What could cause it not to switch screens?
 
Don't recall ever seeing that before. Did everything else on the control work except the NC/PC button?

Yes, I think so. But I only switched it to mdi and turn the spindle on. Tapped and wiggled connections with wooden stick. Nothing obvious with that, but I'll try again later today. Something interesting today is the spindle starts like 90% of the time. Yesterday it would rarely start.. more like 5% of the time.

---update-- an hour later.
Got the NC/PC button working. Push "reset" first and it will swap screens then.

Will get back later today with the Y addresses there.
 
It is a Ikegai tcr25. I have the schematic drawings/book for it.
Tonight the spindle seems to be working and I can't get it to not work. Earlier today, it would go maybe 90% of the time. Here is the page with the Y addresses.

20200504_131805.jpg



This is a photo of the screen from tonight when it kept working. Y0005 bit 6 comes on with a M3 and off with M5.
20200504_125616.jpg



Look at this screen shot. This photo is from earlier today when the spindle was hit/miss working. Y0007bit 7 and 6 are on. Looking at the book, Y0007bit 7 they call SPFIX and Y0007bit 6 isn't anything. Tonight I can't get this screen to appear again with Y0007 doing that. I'll look through the electric book more and see if I can find any more reference to what SPFIX is.
20200504_130043.jpg


Something that is different today is that it rained. I bet the humidity is helping the bad connection work.
 
Concerning SPFIX. M18 is milling mode and M17 is lathe mode. I notice now in that screen that neither M18 or M17 is on (Y7 bit 0 or bit 1). Maybe that is why SPFIX is lit up, as it would need to be one or the other.
 
Y6 bit 6 and 7 look likely to be spindle reverse and forward respectively. Look at the schematic to verify. The mnemonics are chosen by the machine builder. Just looking at a page like you posted without a schematic leaves one just making guesses unless they know the particular builder's naming convention very closely.
 
Here is what it looks like with M5
20200505_074924.jpg



Here it is with M3. Can't get the spindle not to work this morning, but I should be ready now when it quits to see what this screen looks like then.
20200505_074856.jpg
 








 
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