Purge extruder

  • My old Marlin printer used the following clean nozzle start script from S3D:

    G21 ; (metric values)
    G90 ; (absolute positioning)
    M82 ; (set extruder to absolute mode)
    M203 E80 ; (set extruder max to 80)
    G28 ; (home all axis)
    G29 ; (Auto Level)
    G92 E0 ; (reset extruder)
    G1 Z1.0 F3000 ; (move z up little to prevent scratching of surface)
    G1 X0.1 Y20 Z0.2 F5000.0 ; (move to start-line position)
    G1 X0.1 Y200.0 Z0.2 F1500.0 E15 ; (draw 1st line)
    G1 X0.4 Y200.0 Z0.2 F5000.0 ; (move to side a little)
    G1 X0.4 Y20 Z0.2 F1500.0 E30 ; (draw 2nd line)
    ; G1 E27 F1000 ; (retract filament 1mm)
    G92 E0 ; (reset extruder)
    G1 Z1.0 F3000 ; (move z up little to prevent scratching of surface)

    My S3D script i use at the moment with the Duet is:

    G28 XY ;Home XY
    M561 ; Clear any bed transform that might be in place
    G1 X150.5 Y150 ; Move BLTouch Probe to middle of bed
    G30 ; Do a single probe
    M375 ; Load Height Map
    G1 Z20.0 F6000 ; Move Z to 20
    M82 ; set absolute extruder mode

    .. which is fine, but its getting a pain having to quickly clear away the melted plastic off the print surface as it misses out doing the clean nozzle routine.
    It use to print 2 parallel lines, then the nozzle while at the correct print gap forced out extra plastic, lifted up quick then moved to the print start
    What would go where from the old start script, cause when it comes to G Code i'm lost!
    Heat bed size 280x280mm.

  • administrators

    Commands that you want to execute before the GCode file starts executing at all can be put in the start.g macro. But the nozzle hasn't been heated at that point.

    As you need to heat the nozzle before you run the nozzle clean lines, it's simplest to put those lines in the S3D start script, like you did before. Alternatively, you can put those lines (and any other parts of the start script that you want) in a macro file, then use the M98 command in the S3D start script to call that file.

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