Is this possible? Offset code z height during print



  • I am currently using IR sensor and often find that I'd like to lower the z height of the effector just a smidge when starting a print after calibrating.

    It's a pain to run the whole calibration process again, wondering if there would be any way to allow for adjusting the z-height on the fly while printing?


  • administrators

    That's what the babystepping facility is for.



  • @dc42:

    That's what the babystepping facility is for.

    Is there a place where i can read up on the babystepping? and how its used in the duet? ( what functions ect. it can be use for? )
    i cant find anything about it here: https://duet3d.com/wiki/Duet_Wiki

    add a section?

    Thanks!

    ~Russ


  • administrators

    DWC 1.15a and PanelDue firmware both provide babystepping buttons. The underlying gcode command is https://duet3d.com/wiki/G-code#M290:_Baby_stepping.



  • ahhh! now that's a feature worthnoting! i tried to find it but my search was "babystepping" instead of "Baby_stepping" I see why i could not find it 🙂

    I guess ill be reading that entire list of commands 🙂

    so can we change Just one delta home offset on the fly too??? so like if the bed is unlevel but in the direction of the X motor rail?

    humm that would be nice. i normally just move the screw ( i have 3 one at each rail) but this would be done with Baby_stepping??

    Thanks David!

    ~Russ



  • Not sure about that Russ, babystepping just offsets the coordinate system in z only. So if you start a print and for whatever reason the z level is too low or too high, whilst you print a skirt or whatever, you can nudge it up/down in 50 micron (by default) nudges, which you could incorporate into your z-probe offset for the next print, so its kind of a rescue and then tuning tool. This might help if you have a slight tilt and a thick first layer to keep the layer within the zone of adhesion, but you can't nudge individual towers.

    Edit - but I am fairly sure David could do this f you wanted. That being said if I begin a print, especially a large one, and my autocalibration comes back fairly high (above 0.05) or my skirt doesn't lay down well I cancel it, not much time lost at that point is there?


  • administrators

    The baby stepping command in effect raises or lowers the entire bed. If the bed of your delta is tilted and you want to apply a manual correction, you could use the A and/or B parameter on the M666 command.



  • @dc42 thanks as always!



  • @dc42:

    The baby stepping command in effect raises or lowers the entire bed. If the bed of your delta is tilted and you want to apply a manual correction, you could use the A and/or B parameter on the M666 command.

    i find that some times for what ever reason things leaning on way ( going to a rail its high or low) so i have a 3 point leveling system and i just adjust that on the fly…

    but can I do this with the M666 on the fly?

    if yes, for me its normally a need to change the X/Y/Z, so can i do this on the fly while its printing?

    By the way I think this problem comes from the way I have my end stops set up on my old delta....

    ~Russ


  • administrators

    The M666 XYZ endstop corrections are only used when homing, but the A and B tilt corrections are used all the time and can be changed during printing.



  • ok, Thanks!!!!

    you might want to note that on the Gcode page(s) that's good to know!

    ~Russ


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