Z-Axis suddenly out of whack

Discussion in 'Calibration, Help, and Troubleshooting' started by Henry feldman, Apr 7, 2016.

  1. Henry feldman

    Henry feldman Well-Known Member

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    So not sure what happened. Printed a perfectly good job. Went out for a while, then returned to print another job. Everything now prints about 3mm above the bed. I do autohome and it seems to do it, but printing one of the calibration cubes I have stored on the card prints up in the air. I leveled the bed, and the "highest" value was about 1 with some reaching 0 without putting enough tension on the paper. Any idea what happened and what I should do about it? Note, I did take the glass off to clean it between the jobs, but it went right back on and is clipped in place.
     
  2. wfredette

    wfredette Well-Known Member

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    I've run into this problem many times. I don't know what causes it, but the symptom seems to be that the glass bed lowers a bit while the print head makes its way back to the dump bucket to prime. When it leaves the dock, most times, the bed raises back up, but way more often than I'd like, it stays in the lower position.
     
  3. Miasmictruth

    Miasmictruth Well-Known Member

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    Single or dual?
     
  4. Henry feldman

    Henry feldman Well-Known Member

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    Dual
     
  5. Henry feldman

    Henry feldman Well-Known Member

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    But it did the autohome thing, seems to be sort of normal, but just stays 4mm off the bed. I remeasured the sensor to the belt thickness. Releveled. Is it possible there is an offset stored in the firmware? If so, how does one fix it?
     
  6. Rob Heinzonly

    Rob Heinzonly Well-Known Member

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    Did you install the EEPROM Marlin Editor plugin in Octoprint ? I haven't used it yet, but with that plugin it should be possible to read your current Marlin firmware settings.
     
  7. Alex9779

    Alex9779 Moderator
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    You can set offsets for X, Y and Z using M206 command. Offsets set with M206 can be stored in the EEPROM using M500.
    Unfortunately I found no command to read it other than M503 to print your settings but this prints all settings, you gotta search for the "
    Recv: echo: M206 X0.00 Y0.00 Z0.00" in the output.
     
  8. Henry feldman

    Henry feldman Well-Known Member

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    It says:
    Recv: echo:Steps per unit:
    Recv: echo: M92 X160.00 Y180.00 Z1600.00 E295.20
    Recv: echo:Maximum feedrates (mm/s):
    Recv: echo: M203 X150.00 Y150.00 Z3.00 E25.00
    Recv: echo:Maximum Acceleration (mm/s2):
    Recv: echo: M201 X400 Y400 Z100 E5000
    Recv: echo:Accelerations: P=printing, R=retract and T=travel
    Recv: echo: M204 P400.00 R5000.00 T400.00
    Recv: echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s), Z=maximum Z jerk (mm/s), E=maximum E jerk (mm/s)
    Recv: echo: M205 S0.00 T0.00 B20000 X8.00 Z0.40 E5.00
    Recv: echo:Home offset (mm):
    Recv: echo: M206 X0.00 Y0.00 Z0.00
    Recv: Mesh bed leveling:
    Recv: echo: M420 S1 X3 Y3
    Recv: echo: M421 X5.00 Y5.00 Z0.60
    Recv: echo: M421 X130.00 Y5.00 Z0.00
    Recv: echo: M421 X255.00 Y5.00 Z0.95
    Recv: echo: M421 X5.00 Y100.00 Z1.97
    Recv: echo: M421 X130.00 Y100.00 Z1.80
    Recv: echo: M421 X255.00 Y100.00 Z1.90
    Recv: echo: M421 X5.00 Y195.00 Z1.20
    Recv: echo: M421 X130.00 Y195.00 Z0.47
    Recv: echo: M421 X255.00 Y195.00 Z0.45
    Recv: echo:Material heatup parameters:
    Recv: echo: M145 M0 H4294936796 B60 F0
    Recv: echo: M145 M1 H250 B4294945400 F4294943272
    Recv: echo:pID settings:
    Recv: echo: M301 P29.20 I4.73 D45.33 C100.00 L20
    Recv: echo:Filament settings: Disabled
    Recv: echo: M200 D3.00
    Recv: echo: M200 T1 D3.00
    Recv: echo: M200 D0
     
  9. Alex9779

    Alex9779 Moderator
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    That is cool :D

    Back to your problem: sorry I have no concrete idea.
    Do a complete Z level sequence.
    I mean start auto homing with your current settings. Then move the bed up so it touches the nozzles, then level your IR sensor with the belt method. Then level your bed again...

    Unlike what the build manual says I did not use the "ruler method" anymore to level the bed when it is way down.
    I auto home as advised, then move the print head to the middle of the bed.
    Then I turn the Z axis by hand so the bed touches the nozzles and level it by moving the head to the left and the right and turn each Z motor that the nozzles touch the bed. That make the "ruler method" obsolete I think.
    Then I level the IR with the belt in the middle of the bed and then I level the bed...
     
  10. Miasmictruth

    Miasmictruth Well-Known Member

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    Do you have clean glass under the z home or did you put on a surface coating?
     
  11. Henry feldman

    Henry feldman Well-Known Member

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    Yep, totally fixed. I mean sure, I understand why between 2 prints my Z-axis is totally screwed. Anyway a full recommission has returned it to full functionality.

    And yes, @Miasmictruth I do have wolfbite, but I did before when it was working, and after the mechanical recommission it works fine again, I'm guessing the sensor slipped or something...
     
  12. Miasmictruth

    Miasmictruth Well-Known Member

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    It almost sounds like it was reset altogether. Could your finger have slipped and you reset to defaults or something, or maybe shorted something?
     
  13. Miasmictruth

    Miasmictruth Well-Known Member

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    How is wolfbite? I am using 3d-ezz right now.
     
  14. Kick2box

    Kick2box Well-Known Member

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  15. Henry feldman

    Henry feldman Well-Known Member

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    I have all the Wolf products. So far for PLA it is pretty magical, sticks like glue when printing and once it gets cold, it pops off with zero effort (well once getting a frog off was almost impossible, so I had to do the arm water soak and then it came off - then you have to reapply). So far I get about 10-15 prints before having to reapply. Not a huge deal (the bottle holds like 30 applications at least). Just while applying your room smells like vinegar, but after that nothing.
     
  16. Henry feldman

    Henry feldman Well-Known Member

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    OK, @Alex9779 it did it again, after a perfect 15 hour print. The only difference from before this started occurring and now is using the FFF from your github. I have to try Koch's postulate here and reintroduce the original FFF to see if the problem goes away (although I can't imagine what is there, unless there is some weird corruption), then reintroduce your FFF to see if it comes back. I've gone through the generated G-code and don't see anything modifying the Z offset. Any ideas? I have not upgraded my firmware yet (still running stock) so if that's the issue, I can certainly upgrade.
     
  17. Alex9779

    Alex9779 Moderator
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    Ummmm no idea. I don't do anything with Z offset in the profile...
    I am printing only with my profile and every print runs fine...
    Except the heat up problem when starting a print right after another and the hotends are still hot Marlin enters an endless loop. Reported this yesterday, a fix got merged into the RCBugFix branch some hours later...
     
  18. Henry feldman

    Henry feldman Well-Known Member

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    What is weird is then on the last run, it was on for the Z but the Y was totally screwed and back by about the difference between the docked position and the bed (actually printed in space behind the bed and then popped a clip off the glass. I rebooted the printer, re adjusted Z, leveled manually, leveled in Marlin and seems to be fine now.
     
  19. Alex9779

    Alex9779 Moderator
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    I really do anything with Z or other offsets in the profile (that means the startup script).
    All I do is that I home and set the offset for tool 1 if you print with both.
    If you print only with right extruder then homing is done with tool 1. Maybe RC3 has a problem with that?
    I tested that only with RC4 build and there it worked...
     
  20. Henry feldman

    Henry feldman Well-Known Member

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    OK, @Alex9779 you're off the hook, as it is doing it just as frequently with the stock FFF. No idea. This is insanely frustrating. According to my stats I am running a 43% success rate! The last one I had to cancel as it was too tight (and each layer was basically scraping the prior one off the bed). I guess I can go through and re-tighten everything (again) although everything is blue-funked so screws shouldn't be slipping. I'd say once my titan gets here it will be better, but at the moment I can't even count on being able to print that set of parts out!
     

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