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Solved Z axis won't go down, only up

Discussion in 'Troubleshooting' started by Zachary Nicholas Hillman, Jan 16, 2022.

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  1. Zachary Nicholas Hillman

    Zachary Nicholas Hillman New Member

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    Hi I have a robo r1+ and for the past few weeks I haven't been able to print anything at all, for some weird reason my printer is zxs won't go down at all. I use mattercontrol I've never had this kind of problem before, I'm out of control if I press the negative z or positive z the printer will only go up, has anyone have this issue and knows how to fix it? I greatly appreciate the help all three of my 3D printers are down what smoking over here cuz you were complaining about the smoke and I don't want to go buy you why would you go to bed I was taking a couple hits
     
    #1 Zachary Nicholas Hillman, Jan 16, 2022
  2. Zachary Nicholas Hillman

    Zachary Nicholas Hillman New Member

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    Lmao ignore the last part it was talk to text and picked up my girlfriend talking
     
    #2 Zachary Nicholas Hillman, Jan 16, 2022
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  3. fred3d

    fred3d Member

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    I've run into the "up-only" movement with my printer in the past. The solution I used was to power off the printer and manually turn the z-screws until the nozzle touches the bed. With the nozzle on one side, gently raise and lower the z-axis to activate, then de-activate the switch (listen for the click). Move the nozzle to the other side and perform the same adjustment.
     
    #3 fred3d, Jan 17, 2022
  4. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    I know you said on Facebook that the switches were positioned correctly so as I suggested there:

    Do this. With the power off move the carriage with the hotend on it to the HOME position. Then connect with your host program (matter control) and using the GCode terminal (http://wiki.mattercontrol.com/OPTIONS/G-Code_Terminal) in MatterControl send the printer this command:
    M119;
    press enter on the terminal window to send that. The copy-paste what it shows you so we can see. It will be something similar to this:

    ->M119
    <-Reporting endstop status
    <-x_min: TRIGGERED
    <-y_min: TRIGGERED
    <-z_min: TRIGGERED
    <-ok
     
    #4 mark tomlinson, Jan 17, 2022
  5. Thehenryshow

    Thehenryshow New Member

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    I’m having the same issue. All are showing triggered. I moved the print head to the middle and lifted up the carriage on both sides and the. Rechecked and all showed open, so I clicked to start the print and then ran the m119 again and they all
    Showed triggered again. Should there be a gap above that trigger all the time?
     
    #5 Thehenryshow, Oct 23, 2023
  6. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Yes, but you can adjust and use the Z offset in the slicer or firmware to adjust this and fine tune it to where you want it. The FAQ thread discusses using the startup GCode block in your slicer to address this.
     
    #6 mark tomlinson, Oct 29, 2023
  7. Thehenryshow

    Thehenryshow New Member

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    I don’t think we are talking about the same thing. When I click M119 the z_min always shows triggered. When I run the G29 code it does a points check around the bed but every point it moves to it raises the print nossle higher and higher. Please advise. What can we do here?
     
    #7 Thehenryshow, Oct 30, 2023
  8. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    If the Z will only go up (not down) and does this during the autoleveling then one (or both) of the Z home switches is always reading OFF THE BED (OPEN). It could be intermittent in that a HOME command shows them triggered, but as soon as it starts moving it is stuck open (or toggles unexpectedly). That is why it will not go down, it sees the triggered Z home and thinks it is already on the bed so it goes up.
     
    #8 mark tomlinson, Oct 31, 2023
  9. Thehenryshow

    Thehenryshow New Member

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    I thought perhaps the Omron SS5GL2 Microswitch was faulty so I replaced them, it still shows them as triggered so now I'm thinking its electrical. a crossed wire perhaps. Does Robo 3d still service these?
     
    #9 Thehenryshow, Oct 31, 2023
  10. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Robo likely doesn't service the new ones :) The R1's are totally out of the picture.
    On the plus side they are not complicated electrically.
    However if that is not your 'thing' then a local MakerSpace can likely help you out.

    To be clear they should be triggered on the bed (at home) and OPEN when off the bed, but if there is a bad/flakey switch or loose electrical connection then you can get into trouble when then extruder is moving.

    I'd suggest starting with testing the unit by:
    1) homing it and see what they read (M119)
    2) Move to center and leave on the bed and see what they read
    3) move the extruder around randomly (with the nozzle off of the bed) and see what they read.
     
    #10 mark tomlinson, Oct 31, 2023
  11. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    P.S. The switch is more likely the cause than a bad wire, but ... never say never.
    You can trace back the Z stop wiring to the RAMPS board, it is not that complicated.
    Another possibility is to modify the Z switches to be in series rather than parallel.
    Stock they both have to trip to signal ON THE BED but if you switch them to series either one showing triggered will do the job.
    In other words -- if the Z stop shows triggered then both Z switches have been opened, but in series just one of them can trigger and indicate Z Home.

    This means you do have to pay attention to the crossbar being level, but it should be regardless and if it is not that will cause issues with details when printing regardless.
     
    #11 mark tomlinson, Nov 1, 2023
  12. TattooedClover

    TattooedClover New Member

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    I WENT THROUGH THIS EXACT PROBLEM!!! My boyfriend had one he couldn't get to run and I fix robots at work so I jumped in. The electrical was fine but at some point it just stopped working in the same way you mentioned. The z-axis would not home for a print and instead it would continuously go up.

    I found the z axis liner bearings were blown out allowing too much wiggle room when the extruder assembly would shift on the x axis allowing it to continuously toggle the sensors on the sides. Even after manually aligning the z axis as instructed when homing z it would raise every time.

    There are linear bearings (meaning they are to move up and down a shaft rather then in a circular motion like a wheel) on both sides by the spline running up and down the smooth rod for the z axis support.

    If when you manually home your z then shift the extruder assembly from left to right and you see the left side lift out the left side drop when you move the assembly to left it's probably your bearings.

    You can replace these just be careful not to crush the plastic housing. There's two of them on each side.
     

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    #12 TattooedClover, Nov 30, 2024
    Last edited: Nov 30, 2024
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