AMS Magnetic Coupler

I frequently swap between the AMS and an external filament and was looking for an easier way to connect/disconnect the PTFE feed tube. I tried several of the “Y” adapters, but was never able to get these to work reliably. I tinkered around with the concept of a magnetic coupler and it worked fairly well, but I wasn’t happy with the ring magnets I was able to find.

However, I was finally able to source the perfect magnets for this design. And, I have to say, they’re working out really well. Take a look and let me know what you think! Also, @BambuLab, if you think this is a good idea, I’d love for you to incorporate this design in either a future model or offer it as a upgrade.

Bambu Lab AMS Magnetic Coupler


Cool idea! I printed 6 of those Y splitters before I found one that works reliably.

This is a neat solution. I may give it a go. Thank you.

i have been using for a few weeks may be more than a few . I selected this one as did not need anything extra and no issues very happy with it but needs to be printed ABS,ASA,PETG do not print with PLA for me was no good , i used ABS

I’ve never had one of those Y connectors work for me. They always seem to jam the AMS and I use the AMS more often than the external. Plus the jamming AMS is never worth it.

This design looks so neat. How has it been holding up? Any jams? The magnets with the holes are a little pricey from a stand alone website but trying to decide if it’s worth it… I have several of the other parts already like the screw-on bowden tube connectors.

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Yeah, I also wish those magnets were less expensive. I didn’t realize it, but that vendor is based in the UK, so maybe they’re cheaper in Europe. However, they’re really nice magnets. So strong that having two on each side of the coupler is probably overkill. There’s no way they will disconnect when the filament is retracting into the AMS. In fact, the easiest way to separate the coupler is to not pull the halves apart, but tilt one 90 degrees and rock it away. The hexagon pattern makes that pretty easy to do and also helps them line up correctly with minimal effort.

Otherwise, it’s been working really well for me, but could use one improvement. The four 6x3 mm magnets which attach to the rear panel aren’t nearly strong enough to hold when rocking the coupler apart. I want to modify that half of the coupler to have a longer base plate so it can be attached using one of the panel screws. It still functions fine the way it is, it’s just slightly annoying. :slight_smile:

I only had it jam once, but after doing the following it’s been flawless:

  1. The PTFE tube needs to be cut at a clean 90-degree angle. This PTFE Tube Guillotine Cutter works really well for me. Also make sure the tube is pushed all the way to through to the edge of the magnet on both sides so there’s no gap for the filament to snag on.
  2. When feeding filament, try to make sure the end of it is as straight as possible. If the filament is bent (maybe from being stuck in a filament clip for a long time) it might get stuck in the coupler. This isn’t really a problem when feeding from the AMS because it keeps everything nice and smooth when cutting and retracting. Mostly an issue when manually feeding an old spool. Just trim the bent end off before feeding and it works fine.

Finally, and this is a me problem, but I have a bad habit of not reconnecting the AMS before printing with it. That’s fun to watch the filament feed out and retract from the disconnected tube. You’d think after having this happen at least a dozen times I would learn, but no. :melting_face:

This is great and I will be sure to try it out.
Btw: Have you posted it on Makerworld yet? :smiley:

Actually, this is on my list of things to do tonight!

Now more than a Month and i print almost every day , i had only one issue, but not sure if it was the Y or the AMS it self, as The filament edge was bend and after cutting it no problem
In the design i used , i did a tiny counter sink on the exit small connector PTFE tube not sure if really helped.
i do have habit to counter sink all PTFE tubes with small drill and bevel it on the other side with knife or pencil sharpener in the direction of the filament flow , a habit from the Prusa extruder infeed ptfe tube which requires it