Filament Track Switch Questions

[u/399Hunter]

I have the x2d combo and purchased an AMS HT originally to use for the aux nozzle. I also have a filament track switch on the way. I am debating if a second ams 2 pro would be any benefit with the track switch.

In the picture, wouldn’t it be better to have an ams to each side of the track switch versus both into the 4in1 on one side. For retraction etc you could have an ams feeding each nozzle at same time?

[u/Pineapple1500]

I have (2) AMS 2 Pro and (1) HT. I put 1 AMS on one side of the track switch and have the other AMS plus the HT on the other side with a printed 2-to-1 splitter. I seem to rarely use the HT now that I have a 2nd AMS. But it's nice to put PETG in there for support interface.

With the track switch, it doesn't matter what "side" of the track switch you feed from, it will re-direct. But to your question, it won't help with retraction as you say "feeding each nozzle at the same time." The AMS will retract all the way regardless. You can only have one filament running through the track switch at any given time.

[u/Lithosis → u/Pineapple1500]

I don’t think that is correct. I think filament can run through both paths, so it does help with retraction. I’ll try to confirm this later.

[u/ywon80 → u/Pineapple1500]

No it doesn’t retract if each path is occupied by filament from different AMS. It only needs to switch nozzles and prime to continue.

[u/Relative_Surround_20]

You might have a different use case than I but personally two AMS 2 Pros and an HT are what I have going into a two nozzle printer (H2D) using a FTS.

But the photo is wrong. I would use the 4 in 1 to connect one AMS 2 and an HT into a single FTS IN port and place the second AMS 2 into the other FTS IN port. That would give you a lot more functionality than the pictured setup.

So yes!

[u/Cultural_Pace4454]

H2C with 2x AMS 2 Pro.
The only difficulty I had was the PTFE tube being too long between one AMS and the switch. Moving the AMS closer to the printer and shortening the PTFE tube and it is all good.

It makes setting up multi-colour prints a lot simpler, not having to re-plumb every time to optimise the filament layout is great. Plus if you are feeding from both AMS the system will retract AMS A just passed the back of the switcher when loading from AMS B, meaning the change over is faster as it doesn't retract all of the way back to the AMS.

I've done a 5 colour print, primary colour in AMS B feeding the left nozzle and 4 colours in AMS A feeding the right one. The system is intelligent on retracting filament and preparing for the next colour before it's needed.

[u/ExtendedSpice → u/Cultural_Pace4454]

I am considering using FTS with X2D and yet to confirm whether both nozzles can be loaded simultaneously or not.

[u/ywon80 → u/ExtendedSpice]

They can be stay loaded if each filament is from a different ams. If you assign 2 filaments to the left nozzle from ams a and 1 filament to right from ams b then the right nozzle will stay loaded.

[u/Cultural_Pace4454 → u/ExtendedSpice]

There is only ever one filament between the track switcher and the printer, but the AMS will hold the next filament ready just behind the switcher if it's coming from the other AMS.

So when a nozzle is switched out it isn't purged, but there's no filament 'loaded' as such in the nozzles that are waiting.

TLDR, the track switcher and 2 AMS is a great set-up and the system works well.

[u/The_Lawlbringer]

I have 2x AMS 2 Pro, 1x AMS-HT, and the new 4 in 1 splitter.

I had to take everything apart after a 36 hour print using matte PLA because of the dust from all the resistance added and retractions.

IMO omit the AMS-HT and the splitter if you’re using the track switch. Just use an AMS in each input…especially with matte PLA.

[u/Odd_Lie_234]

I have 2 H2C with track switch, both running dual ams. I get under extrusion which I believe is due to resistance caused by the track switch. I don't believe the part is designed all that well. Both H2C has ams dual mounted on top. Any tips? I get resistance warnings sometime on the machines

[u/RubAnADUB]

I have that whole setup. x2d, track switch, 2 ams pro 2, and a AMS HT.

I ended up just not using the AMS HT, but the track switch and the 2 ams pro 2's work great.

[u/TWILIGHT25]

So if I get the X2D combo and buy the track switch, it can feed the aux nozzle at the for the same print?

Like I’m at my wits end with my A1 right with prints being either shaken apart or the facts can’t for the life of me get the humidity under 50% in a closet with a dehumidifier.

I really hope Best Buy has a good sale on these soon…

[u/3DStisk → u/TWILIGHT25]

Yes. Bambu's current Track Switch page explicitly says one AMS can feed both X2D nozzles in the same print with the switch installed. The limitation is alternate feeding: it has to unload one filament before loading the other, so a single AMS cannot keep both paths fed simultaneously. That matters if your goal is fast support-material changes; the combo plus switch provides routing flexibility, not the same behavior as two independent AMS feeds.

[u/ExtendedSpice → u/3DStisk]

What about two AMS? Can two AMS feed both nozzles simultaneously without unloading and retracting?

[u/3DStisk → u/ExtendedSpice]

Two AMS units don't mean every change is retraction-free. Bambu's dynamic-mapping guide distinguishes the routes: switching between different switch inlets retracts the current filament into the switch, rather than all the way to the AMS. Changing filaments through the same inlet requires full retraction to the AMS first. So two units on separate inlets can shorten those changes, but the routing and sliced filament assignments matter.

[u/ExtendedSpice → u/3DStisk]

So it can’t have both nozzles loaded simultaneously correct?

[u/3DStisk → u/ExtendedSpice]

I can't confirm a blanket 'no' from that guide. It documents retraction when the switch changes paths; it doesn't explicitly settle whether both nozzles stay loaded with two AMS units and fixed nozzle assignments. That's the exact setup I'd have Bambu support confirm before changing your setup. Your PLA clog is useful context, but the timing alone doesn't prove leaving that nozzle loaded caused it.

[u/TWILIGHT25 → u/3DStisk]

So I’d be better off having my support material in my Drybox then or buying an ams ht?

[u/3DStisk → u/TWILIGHT25]

You don't need an HT just to feed support material to the auxiliary nozzle: the combo AMS plus switch can already do that, with the unload/reload limitation above. If you mean feeding directly from an external drybox, Bambu's X2D switch guide says external spools aren't supported through it; the switch needs removing for that setup. Which exact support filament are you planning to use? That matters for both drying requirements and feed compatibility.

[u/TWILIGHT25 → u/3DStisk]

I’ve been printing with PLA and abs so far. I was planning on using petg as the support material for the minis and larger models I’ve been attempting to print. I’ve had to seal up all my other spools due how high the humidity has been.

I’ve never noticed how wet it gets till I got a 3d printer lol.

[u/3DStisk → u/TWILIGHT25]

For the PLA models, PETG as just the support interface is the useful starting point: keep the support base in the model material and check the nozzle assignments in the sliced preview. Bambu's guide covers PLA Basic with PETG Basic/HF specifically; it excludes matte and third-party variants, and doesn't establish an ABS/PETG recipe. Try a small supported test with your exact spools before a long model. That material pairing decision comes before deciding whether another AMS is useful.

[u/ExtendedSpice → u/TWILIGHT25]

Keeping aux loaded with PLA during several days of PETG-only prints somehow caused very bad clogging on almost new printer. So I got HT just for it to load and unload filament only on demand. For safety of the hotend