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Solved Robo R1 Z-axis moving during first layer

Discussion in 'Troubleshooting' started by Michael J Hobe, Sep 11, 2019.

  1. Michael J Hobe

    Michael J Hobe New Member

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    As the title says, my Z-axis is rotating during the first layer resulting in an uneven layer and poor adhesion in spots. I've played with all the settings I could think of, changed the G-code and turned off the auto calibration and even made sure my bed was level.
    It seems to rotate the Z-rods 1/2 to 3/4 of the way during a single layer. It is consistent in how it functions. Looking for any ideas or smidgeon of hope for this printer.
     
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    If the Z rods are not staying in sync (one is turning more or less than another) then it is either the RAMPS control board or one of the Z stepper drivers on that board (there are 2 Z stepper driver -- which is silly since one is enough, but there you go).

    If I misunderstand the problem -- post a video on imagur or youtube and link to it
     
  3. Michael J Hobe

    Michael J Hobe New Member

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    I have a link but the dang bot is keeping me from adding it until I have 4 posts. One Z rod is not moving more than the other, during a print both of them rotate while on the same layer. So from what I can tell as the bed moves back and forth the Z rods will rotate in reaction to the bed moving making one side of my first layer higher than the other. With that said I've made sure my bed is level with the print head on all 4 corners. I have a standard R1 so only one driver, which I've changed and tuned to be safe. I dont believe it to be the ramps board or driver at this point. Could another driver somehow effect the Z driver? Or is it just the programming, I'm using the program that came with the machine. I just cant find a reason for the Z to be shifting during a layer.
     
  4. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Well, if you have one Z driver and they don't turn the same... then you have a limited choice of "badness"
    1) Could be the Z driver is just not putting out enough current to drive both steppers.
    2) bad wiring to one of the steppers (loose connection)
    3) One of the steppers is loosing steps because it is flaky/faulty.

    and lastly (in theory) it could be the RAMPS board (but I'd not expect that).
     
  5. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Mechanical binding of one of the threaded rods could also be the case. The R1 (not the R1+) used couplers to link the steppers to the threaded rods and if one of your couplers is loose -- the rods will slip.
     
  6. Michael J Hobe

    Michael J Hobe New Member

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    [​IMG] Here is a link after making a few more posts.

    Essentially the Z is shifting during the layer, not one side but both. I know they're tight in the coupler and the driver is tuned well enough. Could to much current from the driver cause this?
     
  7. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Not too much, but too little. A stepper will only step one full step per pulse (it is driven with PWM signals).
    If it does not have enough drive current then it will drop steps. You maybe told it to do 10 and instead it did ... 3,4, something less than 10

    The Z steppers are 200 steps/revolution.
     
  8. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Too much current will merely make the stepper motor run hot
     
  9. Michael J Hobe

    Michael J Hobe New Member

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    Okay, after failing to add a link let's try it again. Hope this helps give you an idea. Poor angle but you can see how as the bed moves the Z rod does as well.
     
  10. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Are you using autoleveling? If so then the ABL code in marlin will calculate the flat plane and as the bed is moving it WILL move the Z up/down as needed to achieve the 'leveling nirvanna'
     
  11. Michael J Hobe

    Michael J Hobe New Member

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  12. Michael J Hobe

    Michael J Hobe New Member

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    I've been using matter controller since day one but I may try another program to see if I can get different results. I should probably change anyways as I'm reading it is trash.
     
  13. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    It is not my favorite :) it is easy for new users to pick up
     
  14. Michael J Hobe

    Michael J Hobe New Member

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    I've switched over to repetier and ot actually took care of the problem. Now it's trying to undertake the software and get the bed leveled and a good print out now! Thank you for all the help though!
     
    mark tomlinson likes this.

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