Using G2/G3 but can't use all build area.



  • Hi 🙂

    I've been trying to setup a 1/4 circle wipe/purge line on my Delta.
    According to my Config Override G I have a radius of around 135mm

    ; config-override.g file generated in response to M500 at 2019-12-10 17:24
    ; This is a system-generated file - do not edit
    ; Delta parameters
    M665 L271.500:271.500:271.500 R135.758 H290.197 B105.0 X0.255 Y-0.009 Z0.000
    M666 X0.935 Y-0.279 Z-0.655 A0.00 B0.00
    ; Heater model parameters

    However I get outside machine limit fail if running much more than 100mm offset in G3 (as below).
    ;FLAVOR:Marlin
    ;TIME:822
    ;Filament used: 1.61397m
    ;Layer height: 0.25
    ;MINX:-14
    ;MINY:-14
    ;MINZ:0.2
    ;MAXX:14
    ;MAXY:14
    ;MAXZ:19.65
    ;Generated with Cura_SteamEngine 4.4.0
    M140 S60
    M105
    M190 S60
    M104 S220
    M105
    M109 S220
    M82 ;absolute extrusion mode
    G21 ;metric values
    G28 ; home all axes
    M92 E415 ; Sets the correct E-steps for Bondtech
    M107

    G92 E0 ; reset extrusion distance
    G1 X-100 Y0 Z0.3 F3000 ; move to arc start
    G3 X0 Y-100 I100 J0 E40 F400 ; lay arc stripe 90deg
    G92 E0 ; reset extrusion distance
    G1 X0 Y-50 Z4 E-2 F3000 ; get off the bed

    G90 ;absolute positioning

    ;G92 E0 ;zero the extruded length
    ;G1 F200 E3 ;extrude 3mm of feed stock
    ;G92 E0 ;zero the extruded length again
    G1 F120
    ;Put printing message on LCD screen
    M117 Printing...

    Have any of you tried similar?
    The fault occur on the Duet during start of print only and printer just stops there.
    I know there is a collision check introduced but I'm a little puzzled that there is a difference of 35mm from Delta R-value to max possible offset in G2/G3 command



  • I did the same thing, for the I and J you're describing the center of the arc relative to the center of the current coordinate.

    G3 X0 Y-100 I100 J0 E40 F400 ; lay arc stripe 90deg
    

    At that position, your I and J parameters should be I0 and J100 if you are describing 0,0

    I don't believe it takes any probe offsets into consideration, just the nozzle position.



  • @blt3dp I have just found another place in "Machine properties - Drive configuration" that +/- 105 in X/Y is the setting here and this matches the check for limits in my problem.

    Now the function works fine and I get the 1/4 circle/arc at the edge of the build plate to ensure good start of print as filament line is purge/primed and ready to work when starting the job.

    So I guess my problem is solved/explained.

    Thanks for the interest here



  • @Penola

    I tried with 104.99 and this works fine so yes the check lies against the 105mm


  • Moderator

    @Penola said in Using G2/G3 but can't use all build area.:

    M665 L271.500:271.500:271.500 R135.758 H290.197 B105.0 X0.255 Y-0.009 Z0.000

    R135 is your delta radius. B105 is your safe print radius. See delta parameters meanings here: https://duet3d.dozuki.com/Wiki/Gcode#Section_M665_Set_delta_configuration

    Ian



  • @droftarts
    Thanks a lot.
    Haven’t noticed the safe radius setting in M665.
    Makes all the sense in the world now


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