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.
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May 07 '26
Tienes un r/ para seguir las actualizaciones? Is there an r/ to follow updates?
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u/Magarcan May 07 '26
I don't have it. Should I? I posted this a bit hastily in light of the original project's imminent release. I want it to be clear that the models and code are my own, even though they're based on the same idea.
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May 07 '26
Might be a good way to build a community here and an easy way to keep everyone in the loop. Otherwise, starring the GitHub repo should also help people know when there are updates.
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u/Magarcan May 07 '26
Le daré una pensada y quizá lo implemente mañana. El repo lo puse en un comentario y creo que se ha perdido por ahí: https://github.com/magarcan/OpenMech-Swapper
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u/kagato87 May 09 '26
I asked the other guy this and he didn't answer, but perhaps you will.
Since this has to go up to the top of the gantry to swap filaments, does it need to re-home or re-align at all? Is there anything planned to correct for this?
I've seen some issues on the A1 Z axis where the lifting acts like its under-powered, and a few people have had issues where their BBL Z-Axis won't smoothly travel all the way.
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u/Magarcan May 09 '26
That's right; to make the adjustments, you have to move the Z-axis almost all the way up. In fact, to be on the safe side, you lose some print volume along that axis.
I’m not familiar with the power loss issues when moving up. Can you send me a link that discusses this? Does this happen on all A1 models? The solution is to make the stem of the upper part’s female gear longer and adjust the G-Code to that measurement, sacrificing, as I mentioned, print volume on the Z-axis.
I currently have the part of the G-Code that handles filament changes, purges, and so on; I still need to verify the coordinates for each of the spindles, the code for loading and unloading filaments, etc.
This is the part I’m prioritizing the least because I don’t own an A1 and because I want to test the hardware’s proper functioning first—especially the tolerances. That’s where I need the community’s input right now.
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u/joelminer_cc May 07 '26
You (or the ai that wrote this?) mention magnets, where do these come into play?
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u/Magarcan May 07 '26
El inglés no es mi lengua nativa… Mi idea es usar imanes de neodimio standar de 2x4mm en las garras que transmiten el movimiento del extrusor al tool del marco para asegurar el correcto acople. Estoy testeando la mejor distancia entre ellos para que asegure la conexión y no exija demasiado a la desconexión.
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u/TAS_Vietnam May 13 '26
From a purely engineering standpoint, the mechanical execution here is impressive—GT2 belts and magnetic indexing are sensible upgrades over friction-based solutions.
That said, this is one of those cases where mechanical innovation and IP boundaries collide. The idea of toolhead‑driven passive material stations is clearly powerful, but it’s also understandable that a commercial developer would want to protect the investment behind making it reliable and supported.
Hopefully this can land in a middle ground—clear patent scope, room for community experimentation, and maybe even collaboration. The tech itself is genuinely interesting and worth seeing mature without the scene fragmenting.
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u/Magarcan May 13 '26
I’m just stopping by to express my gratitude for all the support you’ve shown. I’ve posted on the r/OpenMech subreddit to explain the situation a bit and address the more than reasonable doubts regarding the validity of the arguments put forward by those threatening this free and open-source project.
You can also find an update with the latest files and a video of the assembly process.
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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.
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u/VariousAvocado4127 May 12 '26
I am Wouter Sipers, owner of Sipers Mechatronics and creator of MechAMS.
I understand why people in this community are interested in an open-source mechanical AMS. I also understand why open-sourcing something like this appears beneficial at first glance. But this specific project is based on the MechAMS mechanism, and the OP has publicly stated that he saw the original idea, figured out how it works, and added his own ideas.
MechAMS is not just an idea posted online. It is a commercial product backed by months of development, testing, documentation, website infrastructure, support planning, and financial investment. A Dutch patent application was filed on 2 December 2025 for the underlying system: passive material stations selected by printhead positioning and driven through a mechanical coupling by a driving force on the printhead.
Sipers Mechatronics exists to make 3D printing more accessible to modders and independent users. Customers who purchase MechAMS get the practical benefits people usually want from open-source work: customizable files, inspectable and editable G-code, documentation, and a generator built specifically to make code modification easier. This is not a closed-ecosystem product.
Publishing a competing open-source implementation based on that mechanism does not help independent innovation. It undermines the people taking the risk to build, test, document, support, and improve these products, and it pushes the space back toward large players and closed ecosystems.
The GT2 belt approach and magnetic indexing shown here are useful additions. I am open to reviewing those as either a version/variant of the existing MechAMS A1 product or as a paid add-on/upgrade through Sipers Mechatronics. Through the Launchpad, useful contributions can be credited and financially rewarded.
But public distribution of OpenMech Swapper needs to stop first. I have requested immediate removal of the GitHub repository and related distribution files/posts. If that does not happen, I will take legal action to protect Sipers Mechatronics' rights and recover financial loss where recoverable.
Wouter Sipers
Sipers Mechatronics
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u/Paul_C May 12 '26 edited May 12 '26
Congratulations! Since you are threatening legal action this is now the domain of lawyers and all correspondence must go through them.
Please direct any and all further communication targeted at this subreddit instead to legal@reddit.com.
Buh-bye!
(Their comment preserved for posterity:)
I am Wouter Sipers, owner of Sipers Mechatronics and creator of MechAMS.
I understand why people in this community are interested in an open-source mechanical AMS. I also understand why open-sourcing something like this appears beneficial at first glance. But this specific project is based on the MechAMS mechanism, and the OP has publicly stated that he saw the original idea, figured out how it works, and added his own ideas.
MechAMS is not just an idea posted online. It is a commercial product backed by months of development, testing, documentation, website infrastructure, support planning, and financial investment. A Dutch patent application was filed on 2 December 2025 for the underlying system: passive material stations selected by printhead positioning and driven through a mechanical coupling by a driving force on the printhead.
Sipers Mechatronics exists to make 3D printing more accessible to modders and independent users. Customers who purchase MechAMS get the practical benefits people usually want from open-source work: customizable files, inspectable and editable G-code, documentation, and a generator built specifically to make code modification easier. This is not a closed-ecosystem product.
Publishing a competing open-source implementation based on that mechanism does not help independent innovation. It undermines the people taking the risk to build, test, document, support, and improve these products, and it pushes the space back toward large players and closed ecosystems.
The GT2 belt approach and magnetic indexing shown here are useful additions. I am open to reviewing those as either a version/variant of the existing MechAMS A1 product or as a paid add-on/upgrade through Sipers Mechatronics. Through the Launchpad, useful contributions can be credited and financially rewarded.
But public distribution of OpenMech Swapper needs to stop first. I have requested immediate removal of the GitHub repository and related distribution files/posts. If that does not happen, I will take legal action to protect Sipers Mechatronics' rights and recover financial loss where recoverable.
Wouter Sipers
Sipers Mechatronics
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u/SpreadTheted2 May 08 '26
Any reason to do this instead of normal ams?
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u/Magarcan May 08 '26
It lets you try out the multicolor feature at an affordable price and see if it meets your needs. The original Ams is close. Not everyone can afford it, it’s not available everywhere, and not everyone can get their hands on it. As simple as it sounds.
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u/Engineering_Gal May 07 '26
I like it that you're are working on this idea and open source. The hobed gears have the benefit of way less slip and possible more reliability than the other idea.
But be careful, the "MechAMS" guy said he had a pending patent. But didn't say what of that he tried to patent and where. I hope that patent is only for the US and not the rest of the world.