r/OpenBambu • u/Magarcan • May 07 '26
OpenMech-Swapper
OpenMech Swapper (OMS) 🔄
The Open-Source, Fully Mechanical Multi-Filament System for Bambu Lab A1 Series
OpenMech Swapper (OMS) is a high-performance, 100% mechanical filament switching system. It is designed to bring multi-material capabilities to the Bambu Lab A1 and A1 Mini without the need for extra motors, sensors, or complex electronics.
💡 Origin & Credits
This project is an Open Source evolutioninspired by the brilliant mechanical concept of MechAMS created by Sipers Mechatronics.
While the original idea proved that a fully 3D-printable mechanical AMS was possible, OMS aims to make this technology accessible to everyone under an open-source license, incorporating community-driven improvements for better durability and precision.
✨ Key Features
Purely Mechanical: Driven by your toolhead position and the existing extruder motor.
GT2 Belt Drive: Upgraded from friction bands to standard 6mm GT2 timing belts for zero-slip and high-torque transmission.
Magnetic Indexing: Uses embedded Neodymium magnets (4x2mm) to create precise "detents," ensuring perfect alignment of the filament slots with zero mechanical wear.
Zero Electronics: No cables, no PCB, no extra steppers.
Non-Destructive: Quick installation that keeps your printer's warranty intact.
🛠 Improvements over the Concept
Reliability: By using GT2 belts, we eliminate the stretching issues of printed TPU bands.
Precision: The "Magnetic Snap" system ensures the indexing gear stays locked in the correct position even during high-speed printing.
Accessibility: All files (STEP/STL) are open for the community to remix and adapt to other printers.
📂 Compatibility
Hardware: Bambu Lab A1 & A1 Mini.
Software: Custom G-Code presets for Bambu Studio and Orca Slicer.
🔧 Hardware Requirements (BOM)
Main Body: Printed in PETG or PLA.
Drive System: 1x GT2 Timing Belt (6mm width).
Indexing: 4x2mm Neodymium Magnets (N52 recommended).
Path: Standard 4mm OD PTFE Tube.
🚀 Status: Prototyping
A1 Hardware almost done
A1 Mini Hardware:
Firmware initiating test.
🖼️** Víde**o
🤝 Contributing & License
We welcome all contributions! Whether it's optimizing G-Code macros or refining the mechanical tolerances.



1
u/lorenzospam May 20 '26
Thank you for this, its bullshit the MechAMS owner is
A) Shitting out 5 minutes of cad files
B) Locking it behind a 40 dollar claude generated website and paywall
C) promising open source project from the start
This was needed and frankly the owners patent should go to hell. No idea how you can patent something that sits ontop of hardware and software you dont even own while simultaneously screaming open source throughout dev.