🧪 Per-Object Flowrate Calibration for Bambu Studio (H2D)

This script provides a workaround for calibrating flow rate on the Bambu Lab H2D, which is currently not supported in OrcaSlicer. OrcaSlicer recently introduced a new top surface pattern to simplify flow calibration, but without H2D support, we can’t use it directly.

Bambu Studio also lacks per-object flowrate settings, so this script performs post-processing on the exported G-code to apply different flow rates per object — ideal for running flow calibration prints.

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📦 What’s Included

• Two .3mf files: These are the YOLO version (linear flow test) exported from OrcaSlicer, using a custom profile tailored for the H2D.

• A Python script: per_object_flowrate.py
  This modifies the G-code to apply calibrated flow rates per object.

  The logic mirrors the implementation in OrcaSlicer:
  OrcaSlicer/plater.cpp#L9855

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⚙️ How to Use

1. Open the .3mf file in Bambu Studio.

2. Slice the project after selecting the filament you want to calibrate.

3. Export the G-code to your local drive.

4. Run the script:

   python3 ./per_object_flowrate.py -g flowrate_1.gcode -p 1 -s 24

   • -g: Path to your exported G-code file
   • -p: The pass index (use 1 for the first pass, 2 for the second pass)
   • -s: Maximum volumetric speed of the filament (in mm³/s)

5. After modifying the G-code, you may want to adjust the slicer’s top surface speed and solid infill speed, since these are tied to the filament's volumetric limit.

   • If the top surface speed and solid infill speed need changing, then start over from step 1 after changing the settings.

6. Send the modified G-code to your H2D, either copy it directly to a USB flash drive or plug the USB USB flash drive in the H2D and use the Send feature in Bambu Studio.

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🎯 Important Notes

• When slicing make sure to have only ONE filament listed under the Project Filaments section in Bambu Studio.
• The filament must be loaded in the left nozzle (for some reason it won't let you change to the right nozzle).
• This script is intended for use with flow calibration prints, not general models.
• This script only supports 0.4mm nozzles and 0.2mm layer height for now (will add more command line arguments later).