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auto leveling

Discussion in 'Troubleshooting' started by Lance Weston, Dec 15, 2018.

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  1. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Yea, I wasn't even going to go there :) The various materials have different behaviors in terms of how much/little they will swell/shrink during this process, but they all do it. Honestly we learn to judge how much it will be and account for it in the modelling process (with some practice you can get really tight final tolerances).

    However the bottom line is that this is a exercise in manually adapting the process to the printer :)

    I agree that we have never gotten hundreths of a mm of accuracy nor have we ever needed to get below tenths, but everyone has a different backstory on what they are trying to accomplish.

    If I need hundreths you can bet I am doing it on a lathe or a CNC mill.

    You might could get that tight on the SLA/DLP one, I honestly have not tried that however it does potentially have somewhat tighter tolerances.
     
    #21 mark tomlinson, Dec 16, 2018
  2. Lance Weston

    Lance Weston Active Member

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    Hi Mark,

    I am not looking for micron tolerances, or rather 50 micron. And the Robo is capable of the repeatability I want. It already does it on the fine tune offset circles. The problem is that my bed material always prints one spot with a higher z offset than the rest of the bed. If I could just get it to store the z offset after each print initialization and then not auto level I would be in good shape. The stepper steps in 1.8 degree steps or 200 steps/turn. It looks like the pitch of the thread is a couple of mm. 2mm/200steps->.01mm vertical for each step. Micro stepping would eve be finer. The IR boards should be good to .02 mm repeatably. If you take the 9 measurements and average them the normal curve would get more narrow, I would expect useful .01 mm. The z endstop switch is probably repeatable to .07 mm multiplied by the ratio of the lever arm anchor to where the lever is pressed, maybe a factor of 3. So a .2mm repeatability is probably okay for most, but I need better. It can be implemented in the firmware. I am just trying to figure out if it is there already by ordering a set of Gcode commands.
     
    #22 Lance Weston, Dec 16, 2018
  3. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    That is what the MESH leveling does, you might want to consider that. Once you work you way through the partial manual process of creating the mesh you never do it again.
     
    #23 mark tomlinson, Dec 16, 2018
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  4. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    #24 mark tomlinson, Dec 16, 2018
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  5. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    If that can't get you the repeatability you need then you absolutely need to consider something changed in the hardware ... new switches perhaps (although those are not hideous that it uses).

    Mine is repeatable to the tolerances you are talking about, yours should be too
     
    #25 mark tomlinson, Dec 16, 2018
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  6. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    The new unified bed leveling is supposed to be even better, but I have zero experience with it.
    Frankly we have all of them manually leveled and don't do any autoleveling any longer, but that is no reason it should not work
     
    #26 mark tomlinson, Dec 16, 2018
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  7. Lance Weston

    Lance Weston Active Member

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    #27 Lance Weston, Dec 16, 2018
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