G-code

Slice with OrcaSlicer, headless (below) or by opening the model in the OrcaSlicer app for the user. The agent never contacts a printer: for a Bambu Lab printer, the result is sent through Bambu Connect; for any other printer, give the user the .gcode.

Install OrcaSlicer

• macOS: brew install --cask orcaslicer. The command line is /Applications/OrcaSlicer.app/Contents/MacOS/OrcaSlicer.
• Windows and Linux: install a release from https://github.com/OrcaSlicer/OrcaSlicer/releases. The command is orca-slicer; on Linux, run it from the AppImage or Flatpak.

Below, <orca> is that command.

Slice headless

OrcaSlicer's command line (https://www.orcaslicer.com/wiki/cli/cli_mode) needs complete presets: it doesn't fill in a preset's parent settings, and it slices only with a process whose compatible printers name the printer. scripts/orca_presets.py (Python 3, no dependencies) writes them from OrcaSlicer's presets, searching the user's own first, then OrcaSlicer's built-in profiles.

1. Find the user's printer, process and filament presets. Prefer the presets the user prints with; never invent one, since a wrong bed size or temperature can damage the printer.

   python scripts/orca_presets.py --list machine --match "MK4S"
   python scripts/orca_presets.py --list process --match "@MK4S 0.4"
   python scripts/orca_presets.py --list filament --match "PLA @MK4S"
   

2. Write the complete presets:

   python scripts/orca_presets.py --printer "Prusa MK4S 0.4 nozzle" \
     --process "0.20mm SPEED @MK4S 0.4" --filament "Prusa Generic PLA @MK4S" \
     --out presets
   

3. Slice. Give --outputdir an absolute path:

   <orca> model.stl \
     --load-settings "presets/process.json;presets/printer.json" \
     --load-filaments presets/filament-1.json \
     --arrange 1 --slice 0 \
     --outputdir /absolute/path/to/out --export-3mf model.gcode.3mf
   

   This writes plate_1.gcode, the plain G-code, and model.gcode.3mf, the sliced 3MF, into that folder. The command line reads .stl, .3mf, .obj and .amf; export STEP to STL or 3MF first (for a text-to-cad model, cad export <id> part.3mf, or cad export part.step part.3mf). Override one setting with --<setting>=<value>, using the setting's key with hyphens for underscores, such as --layer-height=0.16.

Open in OrcaSlicer

When the user would rather pick presets and slice themselves, or no preset can be found, open the model in the app: open -a OrcaSlicer model.stl on macOS, Start-Process model.stl on Windows when OrcaSlicer opens that file type, or orca-slicer model.stl on Linux. The app also reads STEP.

Check before printing

• <orca> model.stl --info prints the model's size; it has to fit the bed.

• Check the slice's settings, which OrcaSlicer writes at the end of the G-code:

  grep -E '^; (printer_model|nozzle_diameter|filament_type|nozzle_temperature|hot_plate_temp|bed_temperature) =|printing time' out/plate_1.gcode
  

  Confirm they match the user's printer and material before anyone prints it.

Hand off

• A Bambu Lab printer: Bambu Connect, with the .gcode.3mf.
• Any other printer: the user prints the .gcode from their printer's app, its web interface (PrusaLink, OctoPrint, Mainsail, Fluidd) or an SD card.