Mesh levelling in corexy



  • Hi. Im doing my mesh levelling setup. I have a core XY printer. I was asking myselg after reading the docs: G32 is suposed to be used for delta printers only? What I want to do is to setup specific points at specific coordinates instead of definen max and minimun corrdinates for each axis to be probe. Can I use bed.g to define these specific points to be probe and use that for my core Xy?
    Thanks in advance



  • G32 is supported for corexy, but in a different way.
    see https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors
    the ability to specify probing points was removed, because it used to much memory, that could be used for other implementations.



  • @Veti I read that, but I was planning to use that feature to adjust both my 2 Z motors in order to be sure they are levelled. So on I have a doubt here: after reading, it is not clear to me how I do the mesh levelling. I launcg the G29 command from inside the bed.g file ?
    Becuse the doc says: You must set up a bed.g file in the usual way with at least as many probe points as Z motors. You can have more if you wish.

    But you hae just said that bed pints specification is not allwed for corexy



  • Hi,

    Let's clarify a few things.

    There is no "mesh leveling".

    There is Mesh Bed Compensation and for that you use G29.

    For leveling the bed there is the Manual Bed Leveling Assistant or Automatic Bed Leveling and for either of those you use G32 and bed.g.

    You can both level the bed and enable bed compensation. If you do you always level the bed first and then enable bed compensation.

    And always remember to use G30 to set the Z=0 Datum. You use it AFTER bed leveling and BEFORE creating/loading the height map needed for bed compensation.

    Read the updated documentation - it may help your understanding.

    Bed Leveling


  • Moderator

    To be clear, what Veti is referring to as being removed is the old form of plane fitting by specifying points. Mesh compensation is a much more capable replacement. You can replicate the old way by using only a few points, or you can increase the number of points and get a much more detailed heightmap of the bed.

    And as fcwilt explains, neither of those things are the same as mechanically leveling the bed.



  • @Phaedrux My specific question would be: Can I specify a total of 60 points, wich coordinates I want to specy in bed.g? and those point will be used by G29 for doing the ABL?


  • Moderator

    Unfortunately no, not at the moment. G29 mesh compensation is geared towards an even grid defined in M557, so it loses the ability to specify arbitrary points , however, it has been requested a few times (for example for avoiding magnets) and is on the wish list to implement some of that lost functionality back into mesh compensation.

    What is your reason for specifying 60 specific points?



  • @Tinchus said in Mesh levelling in corexy:

    @Phaedrux My specific question would be: Can I specify a total of 60 points, wich coordinates I want to specy in bed.g? and those point will be used by G29 for doing the ABL?

    Hi,

    It can be confusing but it helps to get the terminology correct.

    I assume you as using ABL for Auto Bed Leveling.

    If that is the case 60 points makes little sense. Assuming (again) that you have 3 or 4 Z steppers than you need at least 3 or 4 points which is normally enough. You could add a FEW more if desired.

    60 points does makes sense for Mesh Bed Compensation (MBC) but that is not the same as ABL

    The current implementation of MBC only allows for a regular grid of points with a consistent spacing in the X and in the Y direction.

    Frederick



  • @Phaedrux That is exactly my "why". An even grid is not really the best for me, because I have a grid of magnets jajajaja


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