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IndustryArena Forum > Machine Controllers Software and Solutions > Fanuc > Fanuc 18MC hard overtravel all axis, completely stuck
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  1. #1
    Join Date
    Mar 2023
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    7

    Fanuc 18MC hard overtravel all axis, completely stuck

    Having even more problems with my Fanuc 18MC on an Okuma and Howa Millac 438V. Right now the control boots up and I get +/- overtravel alarms on all axis, so it's stuck in emergency stop and won't let me do anything. At first I thought it was the 24VDC power supply, but that looks to be fine, along with all the fuses. Things I've looked at and tried so far

    1. 24VDC power supply - tested fine
    2. Fuses - all good
    3. Emergency stop circuit - all good, closed loop end to end
    4. I thought maybe NC parameters, so far have checked 9xxx and 3xxx NC parameters and all match my backup
    5. I lost the timer and counter PMC parameters years ago before storage, but the machine was at least mostly functional for last few months that it has been plugged in
    6. Controller - Y1000 NC control on bit is 0, so it's not coming on for some reason

    The machine was working the night before, I did power cycle it a lot one evening earlier this week setting the axis home positions, and trying different settings, maybe 15-20 cycles, but it was fine until I came back the next morning. At this point I'm completely lost on what else to do or check. Perhaps it's a physical hardware issue? Or I'm missing something obvious? Any help or advice would be greatly appreciated!

  2. #2
    Join Date
    Dec 2009
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    947

    Re: Fanuc 18MC hard overtravel all axis, completely stuck

    what is the status of the input X8.4?

  3. #3
    Join Date
    Apr 2009
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    1379

    Re: Fanuc 18MC hard overtravel all axis, completely stuck

    Loss of parameters seems likely.

  4. #4
    Join Date
    Jan 2013
    Posts
    474
    Quote Originally Posted by WestEd View Post
    Having even more problems with my Fanuc 18MC on an Okuma and Howa Millac 438V. Right now the control boots up and I get +/- overtravel alarms on all axis, so it's stuck in emergency stop and won't let me do anything. At first I thought it was the 24VDC power supply, but that looks to be fine, along with all the fuses. Things I've looked at and tried so far

    1. 24VDC power supply - tested fine
    2. Fuses - all good
    3. Emergency stop circuit - all good, closed loop end to end
    4. I thought maybe NC parameters, so far have checked 9xxx and 3xxx NC parameters and all match my backup
    5. I lost the timer and counter PMC parameters years ago before storage, but the machine was at least mostly functional for last few months that it has been plugged in
    6. Controller - Y1000 NC control on bit is 0, so it's not coming on for some reason

    The machine was working the night before, I did power cycle it a lot one evening earlier this week setting the axis home positions, and trying different settings, maybe 15-20 cycles, but it was fine until I came back the next morning. At this point I'm completely lost on what else to do or check. Perhaps it's a physical hardware issue? Or I'm missing something obvious? Any help or advice would be greatly appreciated!
    If this were me, I'd power off and hand ball all axis to mid position or at least well away from end positions.

    Then power on holding down P + Cancel until control powers up.

    Usually Fanuc will clear axis overtravel and axis e-stop using this method.

    On Fanuc, not ready although an emergency doesn't have to be emergency stop, it can be numerous things. Emergency stop is quite different and related to the e-stop hard wired 24v input chain.

  5. #5
    Join Date
    Apr 2009
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    1379

    Re: Fanuc 18MC hard overtravel all axis, completely stuck

    Also, the ladder may not be running.

  6. #6
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    Mar 2023
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    7

    Re: Fanuc 18MC hard overtravel all axis, completely stuck

    Quote Originally Posted by zavateandu View Post
    what is the status of the input X8.4?
    That bit is 0, so off.

    Quote Originally Posted by memoryman View Post
    Loss of parameters seems likely.
    That may be possible but as far as I can tell nothing is 0. Unless loss of parameters could be keep relays out of sequence? I've checked the NC parameters, and now the PMC timer, counter, keep relay and data - more on that below/

    Quote Originally Posted by servtech View Post
    If this were me, I'd power off and hand ball all axis to mid position or at least well away from end positions.

    Then power on holding down P + Cancel until control powers up.

    Usually Fanuc will clear axis overtravel and axis e-stop using this method.

    On Fanuc, not ready although an emergency doesn't have to be emergency stop, it can be numerous things. Emergency stop is quite different and related to the e-stop hard wired 24v input chain.
    Hmm, I'm not touching any of the hard limits, and I've confirmed they're all closed circuit at the panel. Will P+Cancel cause parameter loss? Or worse yet could it cause ladder loss?

    An update, as of this morning by some miracle I got a copy of the original parameters of my specific machine (as in the original build sheet). For the NC Parameters I currently have 3 sets of Data, the data on the machine now, a backup from 3 years ago, and the original build parameters. The backup and current are the same, but there are some differences from the original build parameters. I'm also a bit conflicted, the 99xx series parameters, there's a list of them in the NC parameters from the original build, but there's a different set in with the PMC parameters that look to be handwritten from the day the machine was setup.

    Moving on to the PMC parameters, I only have the original build parameters. There's only a couple timers, relays and one data point. The keep relays have some similarities, but they are a bit different, unsure if that is correct or could be locking something up?

    I guess overall I'm just concerned about making thins worse, so trying to slow down and get advice before I make changes. I also can't seem to communicate via rs232 to back things up, so I've taken pictures of the PMC parameters and all the ladder logic. NC parameters I already have, not sure if there's anything else I should be backing up just in case?

  7. #7
    Join Date
    Mar 2023
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    7

    Re: Fanuc 18MC hard overtravel all axis, completely stuck

    I just gave P + Cancel a try, no luck...

  8. #8
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    Jan 2013
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    474
    Quote Originally Posted by WestEd View Post
    I just gave P + Cancel a try, no luck...
    Does your axis have linear scales ? You may want to turn them off and try p and cancel again.

    Are you handy with a multimeter? The emergency stop circuit is like a daisy chain, there could be one or more contacts that need to be closed that are open this losing the e-stop input.

    Check also any safety relays, possibly made by PILS and yellow in colour. These relays have green LEDs that have to be correctly set / reset. If one relay contact is open the fault cannot be cleared. The safety relays can be set by operator, pallet or toolchange door, sometimes doors have reflective sensors. The door may be closed and locked, but if safety relay isn't set by a second (dual) safety switch it will fail.

  9. #9
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    Mar 2023
    Posts
    7

    Re: Fanuc 18MC hard overtravel all axis, completely stuck

    Quote Originally Posted by servtech View Post
    Does your axis have linear scales ? You may want to turn them off and try p and cancel again.

    Are you handy with a multimeter? The emergency stop circuit is like a daisy chain, there could be one or more contacts that need to be closed that are open this losing the e-stop input.

    Check also any safety relays, possibly made by PILS and yellow in colour. These relays have green LEDs that have to be correctly set / reset. If one relay contact is open the fault cannot be cleared. The safety relays can be set by operator, pallet or tool change door, sometimes doors have reflective sensors. The door may be closed and locked, but if safety relay isn't set by a dual safety switch it will fail.
    No linear scales on this machine.

    Yes I've checked with a multimeter across the whole E-stop circuit following the wiring diagram, it's all closed until it gets to the PC7 control board. The PC7 control board is turned on by the Fanuc controller, just it isn't coming on at all. I pulled ribbon cable and metered that out and it seems Y0000 (NC control on) is 0v... I even tried bypassing the PC7 board and forcing the E-stop circuit on with voltage, and it still wouldn't come on...

    I'll comb through the cabinet again this afternoon, there's no safety relay, and almost all the relays are turned on from the PC7 board. There are door switches, but the door interlock key is turned to off, I believe those door switches are all soft stops as ladder inputs.

  10. #10
    Join Date
    Aug 2009
    Posts
    1567

    Re: Fanuc 18MC hard overtravel all axis, completely stuck

    ...you said something about the RS232 not working. I wonder if, you had a power surge thru the cable (if you use cable) on the board has damaged something else. Or maybe its just a param setting for RS232 communication.
    Just a quick thought,
    DJ

  11. #11
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    Mar 2023
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    7

    Re: Fanuc 18MC hard overtravel all axis, completely stuck

    Quote Originally Posted by memoryman View Post
    Also, the ladder may not be running.
    I feel like an idiot, but this was the problem. I guess I must have accidentally bumped that bit. Thanks memoryman and everyone that has chimed in!

    Now to solve the original problem that started all this. My ATC jogs and sequences just fine manually using M31 and M180. But when I command a tool change in MDI, the arm goes, the tool does not unclamp, the arm keeps going and then it unclamps, and the arms swings a couple more times before timing out. As far as I can tell I don't have a tool change macro, the tool change seems to be done by the ladder. Unsure if this is a parameter issue, but I'm thinking I'll try editing the keep relays and 99xx series NC parameters with the original machine build parameters and see? Not sure what else to try, but open to suggestions.

  12. #12
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    Jan 2013
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    474
    Quote Originally Posted by WestEd View Post
    I feel like an idiot, but this was the problem. I guess I must have accidentally bumped that bit. Thanks memoryman and everyone that has chimed in!

    Now to solve the original problem that started all this. My ATC jogs and sequences just fine manually using M31 and M180. But when I command a tool change in MDI, the arm goes, the tool does not unclamp, the arm keeps going and then it unclamps, and the arms swings a couple more times before timing out. As far as I can tell I don't have a tool change macro, the tool change seems to be done by the ladder. Unsure if this is a parameter issue, but I'm thinking I'll try editing the keep relays and 99xx series NC parameters with the original machine build parameters and see? Not sure what else to try, but open to suggestions.
    Found this explanation in other post, might be helpful.

    Look at parameters 6071 thru 6089 and see if you find a 6 next to one of them. If you do, that parameter tells you what the Tool Change program/macro number has to be. Below is a generic tool change routine that I've used on more then one Fanuc machine without trouble. Store it in your control but change the 9001 number to match whatever you find in your parameters.

    Parameter 6071 links to a Subroutine numbered 9001 which is your most likely suspect.
    It goes on in an orderly fashion from there.
    6072 - 9002
    6073 - 9003
    ...
    ...
    ...
    6079 - 9009

    Starting at Parameter 6080 (link 9020) they turn into Macros.
    6081 - 9021
    ....
    ...
    ...
    ...
    6089 - 9029

    (Note: Parameter 3202.4 (NE9) will temporarily have to be set to 0 for the control to accept the new 9000 series program. Turn it back to 1 when you're done.) After changing NE9, do a quick double check of your program list and make sure you're not going to overwrite anything. Not likely, but I always do double and triple takes when monkeying with parameters.

    %
    O9001 (M6 TOOL CHANGE)

    G0G80G40M9
    G91G28Z0M5
    M19
    M6
    G90
    M99
    %

    M6 calling a sub that calls M6, sounds crazy but it works.

  13. #13
    Join Date
    Mar 2023
    Posts
    7

    Re: Fanuc 18MC hard overtravel all axis, completely stuck

    Quote Originally Posted by servtech View Post
    Found this explanation in other post, might be helpful.

    Look at parameters 6071 thru 6089 and see if you find a 6 next to one of them. If you do, that parameter tells you what the Tool Change program/macro number has to be. Below is a generic tool change routine that I've used on more then one Fanuc machine without trouble. Store it in your control but change the 9001 number to match whatever you find in your parameters.

    Parameter 6071 links to a Subroutine numbered 9001 which is your most likely suspect.
    It goes on in an orderly fashion from there.
    6072 - 9002
    6073 - 9003
    ...
    ...
    ...
    6079 - 9009

    Starting at Parameter 6080 (link 9020) they turn into Macros.
    6081 - 9021
    ....
    ...
    ...
    ...
    6089 - 9029

    (Note: Parameter 3202.4 (NE9) will temporarily have to be set to 0 for the control to accept the new 9000 series program. Turn it back to 1 when you're done.) After changing NE9, do a quick double check of your program list and make sure you're not going to overwrite anything. Not likely, but I always do double and triple takes when monkeying with parameters.

    %
    O9001 (M6 TOOL CHANGE)

    G0G80G40M9
    G91G28Z0M5
    M19
    M6
    G90
    M99
    %

    M6 calling a sub that calls M6, sounds crazy but it works.
    I just found the problem. Again another stupid problem, but my 3 phase panel had legs 1 and 2 backwards. Switched it up and it all works now. Phew, what a headache!

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