Retraction on start of print way to high?



  • So I am using Simplify3D setting retraction distance to 1mm speed 125mm (I've heard mixed results between fast and slow, tried them all), using a Titan Areo Extruder. The first layer goes down well, once it's starts...

    We have the initial nozzle wipe as part of the gcode but then when it finishes the wipe it retracts a crazy amount so when it goes to start the print it takes ages before it starts printing. any ideas?

    Config and gcode posted! Thanks in advanced

    0_1562667941776_config.txt 0_1562667945112_First_Layer_Extreme_Test_1.gcode



  • Looking at the gCode it's caused by

    G1 E-1.0000 F7500

    But I can't see why simplify3d is setting it like this, I did have the ender3 profile, but customised the retraction to 1.00mm and 125mm/s



  • I've got it working fine with Cura... I'll just ditch simplify3d for now.



  • @tonyp
    Its the fault of your own start.gcode
    I will mark the critical lines with "<<<<<<<"

    • G28 ; home all axes
      G1 X5 Y10 Z0.2 F3000 ; get ready to prime
      G92 E0 ; reset extrusion distance ..... <<<<<<<
      G1 X160 E15 F600 ; prime nozzle ..... <<<<<<<
      G1 X180 F5000 ; quick wipe
      ; process Process1
      ; layer 1, Z = 0.070
      T0
      G1 E-1.0000 F7500 ..... <<<<<<<
      ; feature skirt
      ; tool H0.200 W0.360
      G1 Z0.100 F1002
      G1 X69.744 Y92.155 F4800
      G1 Z0.070 F1002
      G1 E0.0000 F7500 ..... <<<<<<<
      G1 X160.256 Y92.155 E2.7094 F1200 ..... <<<<<<<

    You reset the extrusion distance to early. After your reset you extrude 15mm of filament, then S3D starts the print naturally with a retraction to move to the start position of your print, which is -1.00mm, so you are retracting a massive 16mm at the beginning.
    Simplify3D is set to absolute extrusion per default, so you should reset your extrusion length before the print moves start.

    The solution is to move the line

    • G92 E0 ; reset extrusion distance

    to the end of your start.gcode or use relative extrusion. You are using absolute extrusion at the moment.



  • @corezair said in Retraction on start of print way to high?:

    use relative extrusion


  • administrators

    This demonstrates well why absolute extruder coordinates should not be used in 3D printing. This problem (and others that are often reported) would not have happened if relative extruder coordinates were standard.


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