gcode-mass-matrix-analyzer 1.0.0

Extract mass matrices from 3D printer G-code files

G-code Mass Matrix Analyzer

A Python package for extracting mass matrices from 3D printer G-code files, including support for zipped G-code files (.3mf) from slicers like BambuLab.

Features

• Material Detection: Automatically detects material types (PLA, PETG, TPU, etc.) from G-code headers
• Density Mapping: Uses built-in material density database or extracts from G-code
• Motion Analysis: Analyzes all extrusion movements including:
  • G1: Linear moves with extrusion
  • G2: Clockwise arc moves with extrusion
  • G3: Counterclockwise arc moves with extrusion
• Smart Arc Subdivision: Configurable angle-based arc subdivision
  • Small arcs (< min_arc_angle) treated as straight lines
  • Large arcs subdivided based on angular resolution for accuracy
• Volume Calculation: Calculates volume of each extrusion segment (linear and arc segments)
• Multi-Material Tracking: Tracks extruder changes and uses correct material density per segment
• Mass Matrix Computation: Generates mass matrix with inertia tensor and total mass
• Usage Statistics: Detailed breakdown of material usage by extruder
• 3mf File Support: Handles .gcode.3mf files with automatic extraction and G-code detection, but you need to rename it first to .gcode.zip

Installation

From PyPI

pip install gcode-mass-matrix-analyzer

From Source

git clone https://github.com/your-username/gcode-mass-matrix-analyzer
cd gcode-mass-matrix-analyzer
pip install -e .

Usage

Command Line

Regular G-code files

python -m gcode_mass_matrix_analyzer example.gcode

Zipped G-code files

The .gcode.3mf file need to be first rename to .gcode.zip.

python -m gcode_mass_matrix_analyzer ~/example.gcode.zip
python -m gcode_mass_matrix_analyzer ~/example.gcode.zip 0.05  # Custom arc angle

Using the command-line tool

gcode-mass-analyzer example.gcode
gcode-mass-analyzer ~/example.gcode.zip 0.05

Python Script

from gcode_mass_matrix_analyzer import GCodeMassMatrixAnalyzer

# Default settings (min_arc_angle = 0.1 rad ≈ 5.7°)
analyzer = GCodeMassMatrixAnalyzer("example.gcode")

# Custom angle threshold (0.05 rad ≈ 2.9°)
analyzer = GCodeMassMatrixAnalyzer("example.gcode", min_arc_angle=0.05)

mass_matrix, stats = analyzer.analyze()
print(f"Total mass: {mass_matrix[3,3]:.6f} kg")

Test with Example File

python test_analyzer.py

Output

The program generates:

1. Console Output: Detailed analysis results including:

   • Material properties detected
   • Object centroid coordinates
   • Total volume and mass
   • Mass matrix
   • Inertia tensor

2. Saved Results: NumPy archive file (*_mass_matrix.npz) containing:

   • Mass matrix array
   • Centroid coordinates
   • Total volume

Mass Matrix Format

The mass matrix has the following structure:

┌─────────────────────────────┐
│  Ixx  -Ixy  -Ixz    0     │
│ -Ixy   Iyy  -Iyz    0     │
│ -Ixz  -Iyz   Izz    0     │
│   0     0     0   mass    │
└─────────────────────────────┘

Where:

• Ixx, Iyy, Izz: Moments of inertia (kg⋅m²)
• Ixy, Ixz, Iyz: Products of inertia (kg⋅m²)
• mass: Total mass (kg)

Supported Materials

The program includes density data for common 3D printing materials:

Material	Density (g/cm³)
PLA	1.24
PLA-CF	1.30
PETG	1.27
PETG-CF	1.35
TPU	1.20
ABS	1.04
PA (Nylon)	1.13
PA-GF	1.35
ASA	1.05

Technical Details

Volume Calculation

Each extrusion segment is modeled as a rectangular cuboid with:

• Length: Distance between start and end points
• Width: Line width (estimated from nozzle diameter × 1.2)
• Height: Layer height (extracted from G-code)

Inertia Calculation

The program treats each extrusion segment as a point mass at its center and applies the parallel axis theorem to calculate moments and products of inertia about the object's centroid.

Coordinate System

• Origin: Object centroid
• Units:
  • Mass: kg
  • Inertia: kg⋅m²
  • Distance: mm (converted to m for inertia calculations)

Limitations

1. Simplified Geometry: Treats extrusions as rectangular cross-sections
2. Point Mass Approximation: Each segment treated as point mass at center
3. Single Extruder Focus: Currently optimized for single-material analysis
4. BambuLab Format: Designed for BambuLab slicer G-code format
5. Absolute Offset: The inertia tensor is relative to the absolute coordinate of the printer, but not the object it self.
6. Inaccurate Mass: The mass estimation is not the same as that from the printer.
7. Material Missalign: If the material has the same name, it will just take the first density for estimation. This need to be fixed by reading the material mapping from config file.

Example Output

Analyzing G-code file: example.gcode
Materials: ['PLA', 'PLA', 'TPU-AMS', 'PETG', 'PLA']
Material densities: [1.19, 1.26, 1.26, 1.25, 1.26] g/cm³
Layer height: 0.08 mm
Filament diameter: 1.75 mm
Object centroid: (174.875, 163.612, 12.620) mm
Total mass: 23.950 g (0.023950 kg)

Mass Matrix (kg⋅m²):
┌─────────────────────────────────────────────────────────┐
│  2.345678e-06  -1.234567e-07  -2.345678e-08        0 │
│ -1.234567e-07   3.456789e-06  -3.456789e-08        0 │
│ -2.345678e-08  -3.456789e-08   4.567890e-06        0 │
│         0               0               0    0.023950 │
└─────────────────────────────────────────────────────────┘

Total Mass: 0.023950 kg (23.950 g)

Contributing

Feel free to submit issues and enhancement requests!

Warning

This code is generated by claude with human supervision. There could still be errors besides the mentionds limitations. Please use at your own risk.