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Solved After Merlin 1.1.9 upgrade, z axis will not raise in print

Discussion in 'Troubleshooting' started by Michael Woodward, Aug 20, 2019.

  1. Michael Woodward

    Michael Woodward New Member

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    My original board burned up. replace it with a new RAMPS 1.4. put the original stock ROBO3DR1PLUSv2 firmware on it and the bed temp went crazy. so tried out some new FW. I was able to get the steady temps with the Merlin 1.1.9BF and did a bit of tuning to get homing to work and the bed leveling. When i finally got to a spot to send a print i noticed that when the G-code for raising the Z axis (G1 Z10 (or any value above 5)) is sent to it the motors buzz and the z axis will not move.

    i should note that i can use pronterface and manually move the z axis with no problems. i can send a G28 and G29 commands and the z axis behaves normally. but when i send any kind of G1 Zxxx command it freaks out.

    I have been reading threads for days, restarting on my FW, trying new FW, etc. i am hoping someone has an idea of where to look to fix this.
     
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Well, acceleration and jerk are probably too high (although see what they are set to in whatever version you are using and post that here).
    Otherwise the stepper driver boards on the RAMPS for the "buzzing" steppers need to be calibrated.

     
  3. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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  4. Michael Woodward

    Michael Woodward New Member

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    DEFAULT_ZJERK = 0.3
    DEFAULT_MAX_ACCELERATION { 900, 900, 100, 10000 }

    so couple of questions about that: if it is a stepper issue shouldn't i see that when it homes or even when it goes through bedleveling? if not why?

    Would the buzzing with no movement be not enough current or too much?
     
  5. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Because little to no acceleration or jerk are involved in those moves. :)
    Those factors are far more at play in sudden direction changes when moving at printing speed.

    I never said stepper. I said stepper driver. The little card on the RAMPS that makes the stepper do its thing and again ... the effort involved in doing the autoleveling dance is minimal (low speed, low acceleration and no sudden direction changes)
     
  6. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Also, those numbers are not obscene and should be OK in the printer.
     
  7. Michael Woodward

    Michael Woodward New Member

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    Thanks for the education on this,

    so is the behavior i am seeing due to too little current on the stepper driver? or too much?
     
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  8. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    That is an excellent question!

    Usually the noises from the stepper indicate it is missing steps (either some or ALL steps) and they need more current, not less.
    Too much current and they just run hotter.
     
  9. Michael Woodward

    Michael Woodward New Member

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    so i think i solved this issue. the potentiometer on the stepper driver did not have a stopping point so i replaced this stepper driver with one from the original board. now it seems to be working as it should. Thanks for your help.

    now i have to figure out why after 15 min. of constant temp, my bed heater starts a wild temp increase. . . but thats another thread!.

    thanks again!
     
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