kicad-export-gerber-mill

A script to export Gerber files from a Kicad PCB for usage with CNC milling machines.

How to run

The script requires Python 3 and Kicad/Pcbnew with Python support. It should be run from command line:

$ ./kicad-export-gerber-mill.py \
      --tool-dia 800 \
      --tool-dia-tolerance 50 \
      --grow-pads 0 \
      --output-dir ./gerber \
      mypcb.kicad_pcb

The arguments used in the example are the default values and can be ommited. Tool diameter is in um, not mm. Please run ./kicad-export-gerber-mill.py --help for details and other arguments.

It is also possible to list the drill sizes used by the PCB using the following command:

$ ./kicad-export-gerber-mill.py \
      --list-pads \
      mypcb.kicad_pcb

Script actions

When running the script, it will:

• Load the board from file
• Patch any PTH pads' drill hole to circular, with the configured tool diameter, if they are into the tolerance of the configured tool diameter.
• Grow PTH pads, if configured.
• Validate vias' drill hole diameter against the configured tool diameter.
• Export bottom copper layer Gerber, relative to auxiliar origin axis.
• Export outline layer Gerber, relative to auxiliar origin axis.
• Export Excellon drill files (PTH and NPTH), relative to auxiliar origin axis.
• Save a copy of patched Kicad PCB file.
• Save a command.txt file with the command-line arguments passed when invoking the script.

It is recommended to validate the output files with a Gerber viewer and/or the exported Kicad PCB file. The script won't change the original Kicad PCB file.

Limitations

• Vias can't be automatically fixed, and the script will just validate their drill hole sizes.