manual bed leveling?

Discussion in 'Motion System' started by Digi2life, Sep 29, 2019.

  1. Digi2life

    Digi2life Active Member

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    I didn't have enough adjustment in the bed frame screws to level it in the x-axis and it also seems a bit off in the y-axis. Is this really just taken care of with mesh bed leveling? For a printer of this caliber, that seems unacceptable. Sure it works, but parts will never have walls perpendicular to floors/ceilings.

    So, has anyone dealt with this? I guess my initial thought is to use washer shims under the plastic standoffs. That should get me within 25 microns, and then I don't need mesh leveling as long as my build surface is flat and there's no sag of the xy gantry.

    Also, are we using the nozzle as the Z probe with the duet's stall detection? What's the repeatability?
     
  2. Digi2life

    Digi2life Active Member

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    OK - should have done a better search. Looks like others have modified to suit already.
    https://forum.e3d-online.com/threads/its-alive-and-questions.3297/

    I think I'll go the route of the long bolt with multiple locknuts. I guess that might cool down the corners of the build plate a bit but I don't often print right out to the extents.
     
  3. Spoon Unit

    Spoon Unit Well-Known Member

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    If you persist with the hex standoff, along with a single locknut, I think you get everything you need. Plus the standoff is made of PPS and will not bleed heat downward so ideally it should remain in the mix. I don't have a perfectly level bed, but I can adjust it pretty well now to be pretty flat:

    [​IMG]
     
  4. Andy Cohen

    Andy Cohen Well-Known Member

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    Theoretically, the mesh leveling should help with the small variations caused by wear, varying levels of Aquanet, etc. It's working well for me even though I have yet to physically level it and it is wayyy out of level. For sure the Omron microswitch works a heckalot better and faster then the BLTouch.
     
  5. Spoon Unit

    Spoon Unit Well-Known Member

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    Even something that looks HORRIBLY out of level on the web interface is probably, in reality, not more than 0.5mm out from end to end. I looks horribly, but the problems are accentuated by the graph.
     
  6. smoki3

    smoki3 Active Member

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    Where can we get these PPS standoffs?
     
  7. Spoon Unit

    Spoon Unit Well-Known Member

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  8. Digi2life

    Digi2life Active Member

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    I ended up buying some PEEK washers from Mcmaster-Carr (https://www.mcmaster.com/93785a212)
    I'll use those with M3 bolts and nuts to get things level and still be insulated.
     
  9. Jai Stanley

    Jai Stanley Well-Known Member

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    I threw my printer togehter: all excited like a giddy kid on christmas day. As such I KNEW I'd have to return to it to properly level.. Sure enough, even after carefully getting as close as possible you JUST see by eye it's not level over the X. With mesh levelling i'm seeing a deviation of about +_0.2mm. Like you I'd like to have it perfect, but the mesh levelling is so good, it keeps going down a step on the list of things to do.
     
  10. Andy Cohen

    Andy Cohen Well-Known Member

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    I intended to manually optimize my bed but the Mesh leveling with this machine is working so well I forgot all about it!
    Seems to me the Omron switch Vs a BLTouch makes a big difference!

    Of course the larger your object in X and Y the more impact one sees with Mesh compensation so I'll eventually get around to adjusting my bed accordingly.
     
  11. Spoon Unit

    Spoon Unit Well-Known Member

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    The graph shown of the state of the bed also accentuates any non-zero numbers. According to the graph, I print on a wave. But in truth, the overall deviations are within 0.2, which is not zero, but it's not a lot either. I've never struggled to make parts that fit together well with such a small deviation.
     
  12. Amr

    Amr Well-Known Member

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    @Spoon Unit are you measuring the mesh bed level while bed is hot or while it is cold, I did it both ways and the difference between cold and hot is concerning, while cold the bed looks level but while hot it seems my bed rises from the bottom left corner about 0.3 mm.
     
  13. Greg Holloway

    Greg Holloway Administrator
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    I usually run mesh levelling with the bed hot, the higher the temperature of the bed the more deflection you'll get and the more important it is to run mesh when it is hot.
     
  14. wHack

    wHack Well-Known Member

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    Always run mesh leveling heated to the temp you intend to print at, after giving it time for your glass to get up to temp.
     
  15. Spoon Unit

    Spoon Unit Well-Known Member

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    My current routine now looks like this for PLA
    • Set bed temp to 80
    • Await bed-mounted thermistor to hit 65
    • Home
    • Run Mesh Bed Levelling
    • Print
    By running mesh levelling with every job, after the bed has reached temp, you're measuring the surface you'll actually print on.
     
    Amr and mhe like this.
  16. Amr

    Amr Well-Known Member

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    makes sense as every time i run mesh bed leveling there is a slight difference in heights
     

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