MicroWeldr

A Python package that converts SVG and DXF files to Prusa Core One G-code for continuous plastic line welding. The package processes vector graphics and generates G-code that creates waterproof welded lines by placing many precise weld "dots" in sequence along the paths, without extruding any plastic material.

Multi-Format Support - Processes both SVG and DXF files with automatic weld type detection based on colors, layers, or filenames.

Optimized for Prusa Core One: Includes chamber temperature control (M141/M191), proper bed dimensions (250×220×270mm), and CoreXY-specific settings for reliable plastic welding operations.

This enables rapid microfluidics prototyping with a 3D printer by creating sealed, waterproof channels and barriers. Each vector path becomes a continuous welded line through precisely controlled sequential dot placement.

Complete welding process showing both normal welds (blue) and frangible welds (red) with 1mm spacing and 2mm diameter dots representing actual welding spots

🆕 Version 6.1.10

• Unified Configuration: Consistent 1mm dot spacing across SVG and DXF formats
• Professional Examples: Complete example collection with combined weld types
• Improved Animations: Uniform timing with 3-second pause for final result viewing
• Proper Weld Heights: 0.1mm normal welds, 0.6mm frangible welds for breakaway functionality
• Comprehensive Testing: Full test coverage including weld height validation
• Modern Dependencies: Updated to pytest 9.0.1, pre-commit 4.4.0, optimized package set
• CI/CD Ready: Complete GitHub Actions workflows with multi-platform testing

Project Structure

microweldr/
├── microweldr/           # Main package
│   ├── core/            # Core functionality & configuration
│   │   ├── config.py          # Configuration management
│   │   ├── unified_config.py  # Unified configuration system
│   │   ├── data_models.py     # Structured data models
│   │   ├── events.py          # Event system for processing
│   │   └── constants.py       # Application constants
│   ├── parsers/         # File format parsers
│   │   ├── dxf_reader.py      # DXF file processing
│   │   ├── svg_parser.py      # SVG file processing
│   │   └── enhanced_svg_parser.py # Advanced SVG features
│   ├── generators/      # Point and G-code generation
│   │   ├── point_iterator_factory.py # Factory pattern for iterators
│   │   ├── svg_point_iterator.py     # SVG point generation
│   │   └── dxf_point_iterator.py     # DXF point generation
│   ├── outputs/         # Output generation
│   │   ├── streaming_gcode_subscriber.py # G-code generation
│   │   └── gif_animation_subscriber.py   # Animation generation
│   ├── cli/             # Command line interface
│   │   ├── simple_main.py     # Main CLI entry point
│   │   └── enhanced_main.py   # Advanced CLI features
│   └── prusalink/       # Printer integration
├── tests/               # Comprehensive test suite
│   ├── unit/           # Unit tests (121 tests)
│   ├── parsing/        # Parser tests
│   ├── outputs/        # Output generation tests
│   └── test_linting.py # Code quality tests
├── examples/           # Professional example collection
│   ├── flask_simple.svg        # SVG example (628 points)
│   ├── flask.dxf              # DXF example (467 points)
│   ├── combined_normal.dxf     # Combined example (801 points)
│   ├── combined_frangible.dxf  # Frangible welds (5 points)
│   └── *.gif                  # Generated animations
└── pyproject.toml     # Modern Poetry configuration (PEP 621)

Features

File Format Support

• SVG Files: Paths, lines, circles, rectangles, groups, and use elements
• DXF Files: Lines, arcs, circles, polylines, and LWPOLYLINES
• Multi-File Processing: Mix SVG and DXF files in single command
• Unit Validation: DXF files must use millimeters (throws exception otherwise)
• Construction Filtering: Automatically ignores construction layers in DXF

Weld Type Detection

Multiple methods for determining weld types:

1. Color-Based (SVG)

• Black elements → Normal welds
• Blue elements → Frangible welds (breakaway seals)
• Red elements → Stop points (pause for user intervention)
• Magenta elements → Pipette points (filling operations)

2. Layer-Based (DXF)

• Normal layers: Any layer name
• Frangible layers: Containing frangible, light, break, seal, weak
• Construction layers: Containing construction, const, guide, reference, ref (ignored)

3. Filename-Based (Fallback)

When colors/layers don't specify weld type, filenames are checked:

• Normal welds: main_welds.dxf, structure.svg
• Frangible welds: frangible_seals.dxf, light_welds.svg, break_points.dxf

Advanced Features

• Configurable Parameters: TOML-based configuration for temperatures, heights, and timing
• Multi-Pass Welding: Configurable initial and final dot spacing
• Optimized Z Movement: Separate weld move height for faster intra-path welding
• Chamber Temperature Control: Prusa Core One chamber heating
• Animation Output: Generates animated SVG showing the welding sequence
• Proper G-code Structure: Includes heating, cooling, and safety procedures
• Error Handling: Comprehensive error reporting and recovery
• Statistics Collection: Processing metrics and validation results

Installation

From PyPI

pip install microweldr

With DXF Support

pip install microweldr[dxf]  # Includes ezdxf for DXF processing

From Source

git clone https://github.com/retospect/microweldr.git
cd microweldr
poetry install --with dev

Quick Start

Basic Usage

# Convert single SVG file
microweldr -weld design.svg -g_out output.gcode

# Convert DXF file with unit validation
microweldr -weld drawing.dxf -g_out output.gcode

# Process combined normal and frangible welds
microweldr -weld main_welds.dxf -frange frangible_seals.dxf -g_out combined.gcode

# Generate animation along with G-code
microweldr -weld design.svg -g_out output.gcode -animation output_animation.gif

Fusion 360 Workflow

Perfect for CAD-based microfluidics design:

1. Design in Fusion 360: Create your microfluidic channels and seals
2. Export two DXF files:
   • main_welds.dxf - Primary structural welds
   • frangible_seals.dxf - Breakaway seals for filling ports
3. Process both files: microweldr -weld main_welds.dxf -frange frangible_seals.dxf -g_out device.gcode
4. Print: Load G-code on Prusa Core One

Configuration

Create microweldr_config.toml for custom settings:

[printer]
bed_x = 250
bed_y = 220
bed_z = 270
chamber_temperature = 45

[movement]
move_height = 5.0  # mm - height for safe movement between paths
weld_height = 0.02  # mm - height for actual welding (touching plastic)
weld_move_height = 2.0  # mm - height for moving between weld points (faster than safe height)
frame_height = 10.0  # mm - height for frame drawing (clearance check)
travel_speed = 3000  # mm/min - travel speed for movements
z_speed = 600  # mm/min - optimized Z speed (near maximum safe limit for Core One)

[normal_welds]
weld_height = 0.1           # mm - structural weld depth
weld_temperature = 160      # °C - nozzle temperature
weld_time = 0.1            # seconds - dwell time
dot_spacing = 0.5          # mm - unified spacing

[frangible_welds]
weld_height = 0.6          # mm - deeper for breakaway functionality
weld_temperature = 160     # °C - same temperature
weld_time = 0.3           # seconds - longer for controlled weakness
dot_spacing = 0.5         # mm - unified spacing

[output]
gcode_extension = ".gcode"
animation_extension = "_animation.svg"

Command Reference

Main Command

microweldr [OPTIONS]

Options:
  -weld PATH           Normal weld file (SVG or DXF)
  -frange PATH         Frangible weld file (SVG or DXF)
  -g_out PATH          Output G-code file
  -animation PATH      Output animation GIF file
  -quiet              Suppress verbose output
  --help              Show help message

Examples

# Single file processing
microweldr -weld design.svg -g_out output.gcode

# Combined weld types
microweldr -weld structural.dxf -frange seals.dxf -g_out device.gcode

# With animation
microweldr -weld design.svg -animation preview.gif -g_out output.gcode

File Format Details

SVG Support

• Elements: <path>, <line>, <circle>, <rect>, <g>, <use>
• Attributes: stroke, class, id for weld type detection
• Namespaces: Handles standard SVG namespaces
• Definitions: Processes <defs> and referenced elements

DXF Support

• Entities: LINE, ARC, CIRCLE, POLYLINE, LWPOLYLINE
• Units: Must be millimeters (validated automatically)
• Layers: Used for weld type and construction detection
• Coordinate System: Preserves original coordinates

Weld Type Examples

Filename-Based Detection

# These filenames automatically detect frangible welds:
microweldr convert frangible_seals.dxf      # → Frangible
microweldr convert light_connections.svg    # → Frangible
microweldr convert break_points.dxf         # → Frangible
microweldr convert seal_layer.svg           # → Frangible

# These default to normal welds:
microweldr convert main_structure.dxf       # → Normal
microweldr convert primary_welds.svg        # → Normal

Layer-Based Detection (DXF)

Layer "main_welds"        → Normal welds
Layer "frangible_seals"   → Frangible welds
Layer "construction"      → Ignored
Layer "break_points"      → Frangible welds

Development

Running Tests

poetry run pytest                    # All tests
poetry run pytest tests/unit/       # Unit tests only
poetry run pytest -v               # Verbose output

Code Quality

poetry run black .                  # Format code
poetry run bandit -r microweldr/   # Security check
poetry run pre-commit run --all-files  # All checks

Building

poetry build                        # Build wheel and source
poetry install dist/*.whl          # Install local build

Examples

Professional Examples

# See examples/ directory for complete example collection:
# - flask_simple.svg (628 points, Bézier curves)
# - flask.dxf (467 points, line interpolation)
# - combined_normal.dxf + combined_frangible.dxf (806 total points)

# Process the combined example
microweldr -weld examples/combined_normal.dxf \
           -frange examples/combined_frangible.dxf \
           -g_out examples/combined_animation.gif \
           -animation examples/combined_animation.gif

Production Workflow

# 1. Design in CAD software (Fusion 360, etc.)
# 2. Export separate files for different weld types
# 3. Process with MicroWeldr
microweldr -weld structural_welds.dxf -frange breakaway_seals.dxf -g_out device.gcode

# 4. Load G-code on Prusa Core One and print

Troubleshooting

DXF Issues

• Unit Error: Ensure DXF uses millimeters in drawing units
• No Entities: Check that layers contain supported entities (lines, arcs, circles)
• Construction Layers: Rename layers to avoid construction keywords

SVG Issues

• No Paths: Ensure elements have stroke attribute (not just fill)
• Complex Paths: Curves are approximated with line segments
• Nested Groups: Deep nesting may affect processing

Weld Type Detection

• Wrong Type: Check filename, layer names, or SVG colors
• All Normal: Add frangible keywords to filenames or layers
• All Frangible: Remove frangible keywords from filenames

Contributing

1. Fork the repository
2. Create a feature branch: git checkout -b feature-name
3. Make changes with tests: poetry run pytest
4. Format code: poetry run black .
5. Submit pull request

License

MIT License - see LICENSE file for details.

Installation

Using uv (recommended)

uv is a fast Python package manager that works on macOS, Linux, and Windows.

# Install uv (macOS / Linux)
curl -LsSf https://astral.sh/uv/install.sh | sh

# Install uv (Windows PowerShell)
powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"

# Create a project and install microweldr
uv init my-welds && cd my-welds
uv add microweldr

# Run microweldr
uv run microweldr -weld design.svg

Using pip

pip install microweldr
microweldr -weld design.svg

Windows notes

MicroWeldr works on Windows with Python 3.11+. If you encounter issues with pyserial, install it separately:

pip install pyserial

USB serial access to Prusa printers requires the appropriate driver (typically installed with PrusaSlicer). The COM port can be specified with -port COM3 (adjust the number to match your system).

Quick start (development)

git clone https://github.com/retospect/microweldr.git
cd microweldr
uv run pytest              # run tests
uv run ruff check .        # lint
uv run ruff format .       # format
uv run mypy microweldr     # type check
uv run microweldr --help   # run the CLI

Security practices

• All GitHub Actions pinned by commit SHA to prevent supply chain attacks
• PyPI publishing via trusted publishing (OIDC) — no long-lived API tokens
• Build provenance attestations on every release (actions/attest-build-provenance)
• Dependabot monitors pip + GitHub Actions dependencies weekly; minor/patch PRs auto-merged after CI passes
• Least-privilege permissions — workflows default to contents: read
• See SECURITY.md for the vulnerability disclosure policy

Changelog

Version 5.3.0 (Latest)

• NEW: Full DXF file support with ezdxf integration
• NEW: Multi-file processing (mix SVG and DXF)
• NEW: Filename-based weld type detection as fallback
• BREAKING: Renamed "light_welds" to "frangible_welds" in all configs
• IMPROVED: Modular CLI architecture with better error handling
• IMPROVED: Publisher-subscriber file processing framework
• IMPROVED: Comprehensive test coverage (33 tests)
• IMPROVED: Structured data models with validation

Version 5.2.x

• Enhanced SVG processing
• Animation improvements
• Configuration validation

Version 5.1.x

• Initial public release
• Basic SVG to G-code conversion
• Prusa Core One optimization