I’m running a Bambu Lab H2D Pro with the dual-extrusion setup, and I have both extruder inputs actively fed by an AMS:
AMS 2 Pro: Connected to the Right Extruder Input.
AMS HT: Connected to the Left Extruder Input.
I need to print non-AMS-compatible materials like TPU 90 and highly abrasive CF-filaments (GreenTEC Pro CF) via the external spool holder to bypass the AMS units.
Since both direct extruder inputs are currently occupied by the AMS units:
Is there a dedicated, third bypass-port on the H2D Pro that accepts the external spool while both AMS units remain connected?
If not, what is the recommended procedure for switching? Should I physically disconnect the PTFE tube of one AMS (e.g., the AMS HT) at the toolhead and plug in the tube from the external spool holder there instead?
Once the external spool is connected to one of the two main extruder inputs, how do I correctly select this “External” filament slot in Bambu Studio for the print job?
Any guidance from H2D Pro users with this specific configuration would be highly appreciated!
you want to put a 4-in-1 Adapter at one or both inputs and connect your AMS PTFE Tube to that Adapter. Then you have 3 more PTFE entry points for each Nozzle.
@sebkoe thank you so much, that helped and solved my current issue and sure them in the future if I get more experienecd. Thanks and greetings from Austria
On the H2D Pro that hole is meant for the filament that you want to route through the bypass path. You feed the filament through that hole, and on the inside – or rather from the inside to the outside – you insert the PTFE tube that then goes to either the left or the right nozzle, depending on how you want to route it.
On my H2D I have all AMS HT bypass outputs connected to a small system of 4‑in‑1 PTFE adapters, and from there a dedicated PTFE tube runs along the cable chain up to the toolhead. I do not split it at the front; instead I simply plug that PTFE tube into the input of the nozzle I want to use for the bypass at that moment.
I recently ran PPA‑CF through the AMS HT bypass like this without any issues, and I also run TPU and PEBA the same way. The nice thing about using the AMS HT as an “external spool” is that you can keep drying the filament while printing, which really helps with moisture‑sensitive materials.
@L0rdS474n oh wow, first of all thank you for this detailed explanation, which really helped me a lot. I some how had that kind of idea in my head, but your confirmation gave me now the last needed confidence.
Thank you so much and greetings from Austria.
Chris
In my setup, I have the PTFE tube that runs to the print head through the rubber grommet, and directly on the outside of the printer I have a 4-in-1 PTFE adapter mounted. Then, at the print head (to avoid disconnecting the PTFE for left/right switching), I’ve printed a small PTFE holder that attaches to the print head.
Use one of the many PTFE holders like this one:
That is, if you choose not to install a splitter on the inside. This way, you can have everything mounted at all times. However, I’ve chosen to manually switch at the print head, since I sometimes use the left extruder for more brittle filaments and the right for TPU/PEBA, etc.
Great that it became clearer! My wife is from Germany, so Austria is a neighboring country. Beautiful country, I must say. One of my goals is to fly there someday when I dare to venture that far
Keep in mind that each connector you add creates a bit more friction in the system, so keep it to a minimum for what you need to do and it will work well.
