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.
This project is an open-source evolution of the mechanical concept pioneered by Sipers Mechatronics with MechAMS.
While the original concept proved that a fully printable AMS was possible, OMS focuses on accessibility and long-term reliability. We’ve moved to an open-source license and incorporated community feedback to improve durability and precision. Some improvements have also been made to the original concept.
- Purely Mechanical: The system is driven entirely by the toolhead’s movement and the existing extruder motor.
- GT2 Belt Drive: We ditched 3D-printed TPU bands in favor of standard 6mm GT2 timing belts to eliminate slip and increase torque.
- 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: GT2 belts don't stretch or snap over time like printed bands do.
- Precision: The "Magnetic Snap" system keeps the indexing gear locked during high-speed moves.
- Open Access: All G Code and STL files are available for the community to remix or port to other printers.
- 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.
Unfortunately, I don't even own a 3D printer, so I'm really counting on you to help refine the hardware.
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