Content of this Document

The purpose of this document is to detail the GCode settings for the GCode generation inside ChopChop3D Slicer:


GCode is in general the langua franca of most 3D Printers. We will cover the different settings in this document.

GCode Tab

General Settings

The GCode panel contains parameter used for the GCode generation and some important parameters regarding Origin and Offset of the Printer.

  • Edit Start GCode opens an instance of the GCode Editor that is used to set a piece of GCode that will be written at the Start of the GCode File.
  • Edit End GCode is similar to the previous one, but it sets the piece of GCode that will be written at the End of the GCode File.
  • Edit Layer Start GCode is a specific piece of GCode that is written at the start of a new Layer.
  • Edit Layer End GCode is similar to the previous one, but this time the GCode will be written at the end of each Layer.
  • Origin X, Origin Y and Origin Z sets the origin of your printer.
    NB: ChopChop3D origin is set in the middle of the Bed. Be Careful with this parameter otherwise you can damage your printer.

    Example for Marlin with a Cartesian machine: the origin is set to the middle X and the middle Y.
    In the following example, the machine is having a bed with on X 210mm and on Y 210mm then, the origin is set to X 105mm and Y 105mm.

    You can also play with the Z origin at your own risk, if you want to tune the height of the first layer.

  • Dialect is the GCode dialect used by your 3D printer (RepRap, Makerbot, UltiGCode, Griffin)
  • Use Firmware Retraction if you want to use the firmware retraction instead, and the associated GCode Scripts for the Retraction and DeRetraction
  • Slice from the Bed, when enabled if you did not align perfectly a part to touch the bed, it will do it automatically.
  • Reset Extruder for each Layer, it puts a G92 E0 at each layer, some firmwares do not work correctly with this.
  • Reset Extruder for each Tool Change, similar to the previous case but it is performed only at the Tool Change

Post Processing

The Post Processing tab is at follows, once the GCode file has been generated, the Post Processing takes place, if any is defined.

  • Post Processing opens the dialog used to set optional GCode Post Processors after the generation of the GCode File.
  • Use GPX tells is we have to use GPX Tool to generate GCode for Printers using Makerbot and Sailfish based firmwares.
  • GPX Settings open the dialog used to set specific settings for GPX.

GCode Post Processing

This dialog is used to set a list of actions performed at the end of the GCode File Generation.
You need to perform a right click to raise the Contextual Menu that will enable you to perform the following actions:

  • Move Up, Move Down are used to set the order of entries for the execution.
  • Insert is used to create a new entry.
  • Delete is used to delete an existing entry.
  • Duplicate is used to duplicate an existing entry.
  • Edit CmdLine is used to edit the CmdLine field that can be quiet long.

NB: Inside the CmdLine, the current gcode filename is stored in the variable named: "${GCODE_FILENAME}".

GPX Settings

This dialog is used to set the list of parameters for GPX. GPX is a tool translating GCode text commands to the commands used by Makerbot Replicators and clones.
This tool has been created by Henry Thomas link and it is currently maintained by Mark Walker GitHub link .
ChopChop3D Slicer contains a binary executable of GPX, sources are unmodified last git revision from Walker's repository.

This first panel sets the machine type either through the combobox listing predefined machine types, or through a Custom Machine Type that can directly specified. It is also possible to set X,Y and Z offset accordingly.

The second panel sets options specific to GPX.

The third panel sets the GPX Path and Filename, the Custom Machine File Definition, optional EEPROM Setting Definition and both Output Path and Output Filename.

The fourth panel shows the generated GPX Cmd Line accordingly to provided settings in previous panel. Still, a Custom GPX Cmd Line is provided in case previous settings do not fully cover everything.

When you will save the GCode, the GPX GCode Runner dialog will pop-up as follows.

Advanced Settings

This tab contains the following settings :

  • X/Y Precision: the precision (number of digits after the dot) written in the GCode file for X/Y moves.
  • E Precision: the precision (number of digits after the dot) written in the GCode file for Extrusion moves.
  • Z Precision: the precision (number of digits after the dot) written in the GCode file for Z moves.
  • Verbose: a flag adding details about the different print phases.
  • QuickSlicer specifics

    At the QuickSlicer, the Default Extruder is implicitly defined, you need to set the Tool settings at the GCode Panel, which is similar to the one found at the Extruder dialog as detailed here

    It contains the Tool, the associated Tool Change scripts, the Offsets. ChopChop3D Slicer is using symbolic tools, it means that the identifier used for the parameter Tool can be whatever is meaningful for you. The real tool from the GCode point of view will have to be set in the Tool Change script. We think it enables further customization and more freedom.

    Slicer specifics

    There are no specifics for the Detailed Slicer.