Automatically fix problematic Makerworld 3MF files that cause errors in slicers like Anycubic Next, OrcaSlicer, and others.
When downloading 3MF files from Makerworld, many slicers (especially Anycubic Slicer Next) show this error:
tree_support_wall_count: -1 not in range [0,2]
or
raft_first_layer_expansion: -1 not valid
This prevents you from opening the files in your slicer. 😤
This app automatically fixes those files! Just point it at your downloads folder, and it monitors for new 3MF files and fixes them in real-time.
- ✅ Monitors a folder for new/modified 3MF files
- ✅ Automatically replaces
raft_first_layer_expansion = -1with0 - ✅ Automatically replaces
tree_support_wall_count = -1with0 - ✅ Creates backups before modifying (
.3mf.bak) - ✅ Works with batch processing for existing files
- ✅ Simple GUI - no technical knowledge needed
⬇️ Download 3MF-Sanitizer-v1.1.zip
- Size: ~10 MB
- Platform: Windows 10/11
- No installation required - just extract and run!
- Download
3MF-Sanitizer-v1.1.zipfrom Releases - Extract the ZIP file
- Run
3MF-Sanitizer.exe - Select Folder - Choose your downloads folder
- Start Monitoring - App watches for new files
- Done! - Download 3MF files from Makerworld and they're automatically fixed
┌─────────────────────────────────────────────┐
│ 3MF Sanitizer │
│ Fixes negative parameter values in │
│ Makerworld 3MF files │
├─────────────────────────────────────────────┤
│ Watch Folder │
│ C:\Users\YourName\Downloads │
│ [Select Folder] [Process Existing Files] │
├─────────────────────────────────────────────┤
│ [Start Monitoring] [Stop Monitoring] │
│ Status: ● Monitoring │
├─────────────────────────────────────────────┤
│ Activity Log │
│ [10:23:45] Detected: model.3mf │
│ [10:23:46] ✓ Fixed 2 parameters │
└─────────────────────────────────────────────┘
- 🔄 Real-time Monitoring - Automatically detects new files
- 📦 Batch Processing - Fix all existing files at once
- 💾 Safe Backups - Original files saved as
.3mf.bak - 📊 Activity Log - See exactly what was fixed
- 🎯 Simple GUI - User-friendly interface
- 🔒 Offline - No internet connection needed
- 🆓 Free & Open Source - MIT License
- ✅ Makerworld
- ✅ BambuLab
- ✅ Prusa
- ✅ Other 3MF sources
- ✅ Anycubic Slicer Next
- ✅ OrcaSlicer
- ✅ BambuStudio
- ✅ PrusaSlicer
- 3MF files are ZIP archives containing configuration files
- The app extracts the archive
- Searches for problematic parameters in config files
- Replaces negative values with valid ones (0)
- Re-compresses and saves the file
- You can now open it in your slicer! 🎉
Parameters Fixed:
raft_first_layer_expansion: -1→0tree_support_wall_count: -1→0
Files Modified:
Metadata/model_settings.configMetadata/project_settings.configMetadata/slice_info.configMetadata/*.json
Formats Supported:
- INI-style:
param = -1 - JSON integer:
"param": -1 - JSON string:
"param": "-1"(v1.1 fix)
"Windows protected your PC" warning?
- Click "More info" → "Run anyway"
- This warning appears because the app isn't digitally signed (costs $$$)
- The app is safe - source code is available for review!
Files aren't being processed?
- Ensure monitoring is started (status shows green)
- Check files have
.3mfextension - Look at Activity Log for errors
Still getting slicer errors?
- Check Activity Log to confirm fixes were applied
- The error might be unrelated to these parameters
- Try comparing with the
.3mf.bakbackup
- Python 3.10 or higher
- Windows with Long Path support enabled
# Clone the repository
git clone https://github.com/yourusername/3mf-sanitizer.git
cd 3mf-sanitizer
# Install dependencies
pip install -r requirements.txt
# Run from source
python main.py
# Or build executable
python build.pySee BUILD_INSTRUCTIONS.md for detailed build steps.
Contributions are welcome! Please:
- Fork the repository
- Create a feature branch (
git checkout -b feature/amazing-feature) - Commit your changes (
git commit -m 'Add amazing feature') - Push to the branch (
git push origin feature/amazing-feature) - Open a Pull Request
- ✨ Fixed detection of JSON string values (
"param": "-1") - ✅ Now works with real Makerworld files
- 🐛 Bug fixes for parameter detection
- 🎉 Initial release
- ✅ Core sanitization functionality
- ✅ GUI application
- ✅ Folder monitoring
- ✅ Batch processing
See CHANGELOG.md for full version history.
Q: Is this safe? A: Yes! The app creates backups before modifying files, and the source code is open for review.
Q: Will this work on Mac/Linux? A: Currently Windows-only, but the Python source can be adapted for other platforms.
Q: Can I add more parameters to fix?
A: Yes! Edit sanitizer.py and add parameters to the FIXES dictionary.
Q: Does this need internet? A: No, it works completely offline.
Q: Why isn't it signed? A: Code signing certificates cost hundreds of dollars per year. As a free open-source project, we don't have that budget. The source code is available for anyone to audit.
- 🐛 Bug Reports: Open an Issue
- 💡 Feature Requests: Open an Issue
- 📖 Documentation: See QUICKSTART.md
Help spread the word!
- Share on Reddit: r/3Dprinting, r/anycubic
- Post in Makerworld forums
- Share in Facebook 3D printing groups
MIT License - Free for personal and commercial use.
See LICENSE for details.
Created to help the 3D printing community deal with incompatible 3MF files.
Special thanks to:
- The 3D printing community for reporting issues
- BambuLab for 3MF format documentation
- All contributors
Made with ❤️ for the 3D printing community
If this tool helped you, consider giving it a ⭐ star on GitHub!