Making babysteps permanent in gcode



  • So I think I'm over the major hurdles with the Duet 2 Maestro on my Ender 5 Plus (thanks in large part to this community, I cannot thank you all enough). One of the last things I had to tackle was a good first layer. I was struggling with the fact that my nozzle was too close to the print bed. Using some advice and reading I learned how to use the baby steps feature to work to dial it in.

    My question; Once we have that dialed in the way it should be, how do we take that offset number from the baby steps and make it permanent in gcode? I am new to reprap as I was on Marlin with my older makerfarm prusa i3 clone.

    Thanks again in advance for any help you can offer!



  • How are you setting Z? A switch? A bltouch?

    I ask because the answer is "adjust the Z offset in whatever defines Z". But that doesn't tell you specifically enough... so, what defines Z0?



  • @Danal thank you for replying! I use the bltouch that came stock with the printer.



  • Take a look at G31:

    https://duet3d.dozuki.com/Wiki/Gcode#Section_G31_Set_or_Report_Current_Probe_status

    I believe this will do what you want, offset Z. You would put it in your config.g AFTER the M558 that defines the probe.



  • In my config.g I have this command

    M208 X-2:277 Y-5:300 Z-3:285 ; XYZ min/max

    And I apply permanent baby steps by adjusting the Z value in reversed direction. E.g. if baby steps was +0.2mm I substract 0.2mm from the Z value.

    Sometimes I also just set the Z offset in my slicer since optimal baby steps for PETG and PLA are different on my machine, maybe because of the different bed temperature, not sure.



  • @zapta said in Making babysteps permanent in gcode:

    M208 X-2:277 Y-5:300 Z-3:285 ; XYZ min/max

    no as danal said, you use the G31 to adjust the offset of the probe not M208


  • Moderator

    Can you post your full config and homeall? Then we can tell you exactly what needs to be changed. I get the sense that things are more complicated than they should be.



  • @Phaedrux, whose's config file are you asking?


  • Moderator



  • @Phaedrux, just saw your reply. My config files here here https://github.com/zapta/misc/tree/master/hevo/duet/sys and any feedback will be greatly appreciated. This is a HyperCube Evo corexy with BMG direct drive extruder.

    Some notes:

    1. The acceleration/jerk is pretty low I think. I wonder if I can squeeze more from my machine. Construction is on the stiff side of HEVO.

    2. Per the thread here, I am setting baby steps in a non standard way. I also have my slicer set for +0.25mm z offset.

    3. X/Y homing is using stepper stalling. I am using mode_normal.g and mode_stall.h to control setting for normal operation and for stall based homing but would be glad to get rid of it.

    4. I don't use individual x,y,z homing. Just homeall.

    5. Printer has no z switch. I am using BLTouch for z homing, at the center of the 300x300 bed. Bed is heavy 6mm tooling cast aluminum.

    Thanks,


  • Moderator

    @zapta

    M566 X300  Y300 Z100 E900    ; Set maximum instantaneous speed changes (mm/min) (Jerk)
    M201 X300  Y300 Z60  E600    ; Set maximum accelerations (mm/s^2)
    

    Yeah that's very very low. See here for some tuning methods

    Or give these a shot. The HEVO isn't all that different from my Dbot. This is what I use for conservative values.

    M566 X900 Y900
    M201 X700 Y700
    

    If you used those settings you probably wouldn't need to use the separate mode_stall settings.

    As for the Z height setting. Whatever works for you I guess, but it does seem a bit complicated.

    The homeall looks fine, but I noticed you return the z motor current to normal before doing the final probing. If you're trying to protect against damage in case of a failed probing you might want to move the current return to after.

    M913 Z100         ; Z motors to 100% current
    M558 A5 F100	  ; Set for probing at slow speed, allow multiple trys
    G30               ; Probe and home Z
    


  • Thanks @Phaedrux, this is very useful.

    1. Regarding the M566, M201, your examples listed only X,Y. Should I omit Z and E or use my existing values?

    2. Regarding the Z current, I think my thinking was that once the BLTouch triggered once successfully, it's safe to use the normal current and make the conditions consistent with real operation.


  • Moderator

    @zapta your z and e settings are pretty conservative too. For z it only needs to be as fast as needed to keep it from causing problems with mesh compensation or delays at layer change causing blobs.

    For E it would be a matter of tuning along with retraction and pressure advance. The extruder isn't moving a lot of mass around so it can be very quick without problems. My values are an order of magnitude higher than yours for direct drive for instance. 3000-4000 should be enough to let pressure advance do its thing without slipping or skipping. Does not apply to remote direct drive or very high gear ratio drives.


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