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Solved OK, here's a wierd one....

Discussion in 'Troubleshooting' started by Bill Monroe, Feb 22, 2015.

  1. Bill Monroe

    Bill Monroe Member

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    My Z axis suddenly wont go down.. When I try, the LCD reports: endstops hit: Z
    Limit switches you say?? I thought so too but that's not it. When I tell it to go down, it doesn't go up (like when the limit switches are not right. In fact, it *sounds* faintly like it's trying to go down - I can hear the motors lightly pulsing.
    My understanding (someone correct me if I am wrong) is that the Z limits are actually grounding the pin when the switch unloads.. if that is true then....
    Tried un-plugging the Z limits switches completely - still wont go down.
    So, I tried changing the stepper board, put in a RioRand unit.. no change (except the motors are MUCH quieter when they go up).
    At the moment, I'm at a loss....
     
    #1 Bill Monroe, Feb 22, 2015
    Last edited by a moderator: Feb 22, 2015
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    So can you easily turn the Z rods by hand with it powered off? Eliminates a mechanical jam of any sort.

    I think the Z switches are normally closed and OPEN when they are 'at limit' so removing or disconnecting them would not help that... jumping around them might :)

    Do they show triggered in the console widow? I think you use an M119 GCode command to request the status.
     
    #2 mark tomlinson, Feb 22, 2015
  3. Bill Monroe

    Bill Monroe Member

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    I checked the switch assy with a meter, unloading either one closes the circuit.
     
    #3 Bill Monroe, Feb 22, 2015
  4. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    OK, no luck then. (I have a beta--no R1 to play with) :)

    Have you changed/updated the firmware recently? If it isn't a hardware problem it could be software...

    The M119 might still be useful to try since that will report what state the firmware thinks they are in
     
    #4 mark tomlinson, Feb 22, 2015
  5. Bill Monroe

    Bill Monroe Member

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    I did change the firmware (for dual nozzles) but put the original back to troubleshoot.

    how do I send the M119?
     
    #5 Bill Monroe, Feb 22, 2015
  6. Bill Monroe

    Bill Monroe Member

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    ok, figured out how to send the M119 with simplify3D (been using the SD so long I forgot how to talk to the machine in real time) :)

    says Z is triggered so there's the problem.. more poking around to do....
     
    #6 Bill Monroe, Feb 22, 2015
  7. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    You need a console... I don't use matter control, but all of the various packages have a console window.
    In Simplify it is on the Machine Control Panel under the communications tab. You would type in M119 then click SEND.

    Here is a link I found for MC that might help:

    http://wiki.mattercontrol.com/Terminal

    edit: Never mind-- you got it
     
    #7 mark tomlinson, Feb 22, 2015
  8. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Yea, I almost always use the Sd card myself. Certainly for anything long.
     
    #8 mark tomlinson, Feb 22, 2015
  9. Bill Monroe

    Bill Monroe Member

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    Well, I've checked the switches using M119 - everything seems to be OK. lift either side and it shows open, when both are in place is says triggered. Apparently it's reverse logic from the X and Y?
    I'll go back and look at the firmware..
     
    #9 Bill Monroe, Feb 22, 2015
  10. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Yes, the triggered is backwards from the Z as compared to the X/Y
     
    #10 mark tomlinson, Feb 22, 2015
  11. Bill Monroe

    Bill Monroe Member

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    Fixed it.
    Apparently, the Marlin copy I was advised was "original" wasn't quite right - in Conguration.h it had:

    const bool Z_MIN_ENDSTOP_INVERTING = false; // set to true to invert the logic of the endstop.

    Which should be:

    const bool Z_MIN_ENDSTOP_INVERTING = true; // set to true to invert the logic of the endstop.


    Thanks for hanging in there, Mark..
     
    #11 Bill Monroe, Feb 22, 2015
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  12. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    :)

    Glad you found it
     
    #12 mark tomlinson, Feb 22, 2015

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