OpenMech Swapper (OMS) is a 100% mechanical filament switching solution for the Bambu Lab A1 and A1 Mini. It allows multi-material printing without requiring extra motors, complex electronics, or proprietary sensors.
OMS (OpenMech Swapper) is an open-source experimental project exploring mechanical approaches to multi-material filament switching for desktop FDM printers.
OMS was developed after observing publicly demonstrated mechanical concepts in MechAMS and other MMU projects, but all CAD, implementation details, and hardware were recreated independently and significantly modified.
OMS focuses on:
- open-source accessibility
- modular mechanical experimentation
- use of standard off-the-shelf components
- community-driven iteration and testing
All OMS CAD, STL, and software components are released under an open-source license for community experimentation and adaptation.
- Purely Mechanical: The system is driven entirely by the toolhead’s movement and the existing extruder motor.
- GT2 Belt Drive: Uses standard 6mm GT2 timing belts for improved torque transmission and long-term reliability.
- Magnetic Indexing: Uses 4x2mm Neodymium magnets to create physical "detents." This ensures that the clutch plates remain perfectly aligned at all times without causing wear on the mechanical components.
- Plug & Play (Mostly): No electronics, no PCBs, and no extra steppers. It’s a non-destructive mod that won't void your warranty.
- Reliability
- Precision
- Open Access
- Printers: Bambu Lab A1 & A1 Mini.
- Slicer: Compatible with Bambu Studio and Orca Slicer (requires custom G-Code presets).
- BOM Highlights:
- PETG or PLA for the body.
- Standard 6mm GT2 Belt.
- 4x2mm Neodymium Magnets (N52).
- MR 115 Bearing.
- Standard 4mm OD PTFE tubing.
- Pneumatic coupling PC4-M10
- Steel D-Shaft 5mm x 90mm
- Prusa Mk3s Extruder Gears
The files are currently located in the “Hardware/” folder, and the preliminary G-code logic can be found in “Software/”. The priority is to get the hardware up and running before prototyping the software.
Community testing and feedback are currently essential to validating hardware tolerances and mechanical reliability across different setups.
We’re looking for help with G-Code macro optimization and mechanical tolerance refining. Feel free to open a PR or an issue.
License: MIT
OMS does not include, redistribute, or reuse proprietary MechAMS assets, files, or documentation.