[feature request] TPU on the AMS

I know TPU is not currently supported on the AMS, but it’s an amazing material and it’s such a pain to manually swap whenever I want to print a flexible, impact resistant part

I’ve found that harder TPUs like Priline 98a print fine from the AMS, but buckle in the AMS feed path during retraction at the end of a print. Would it be possible to tune the toolhead, AMS hub, and AMS drive to keep the filament under tension during retraction?

Is there any way that TPU could coexist with the AMS in the future, perhaps in an X1Pro IDEX device?

The buckling is caused by the flexible nature and the larger diameter of the PTFE tube compared to the diameter of the filament.
You could switch out all the PTFE tubes in the AMS and printer with Creality Capricorn tubes that offer a much smaller inner diameter and thus resist the buckling much better. They also reduce the friction by a small amount, helping the AMS.

1 Like

I’m still gun shy on putting 95A tpu through my AMS even though I swapped out all my ptfe for Cap tube

It would certainly be a cool feature to mix tpu with other filaments but even if the ams accepted the tpu the single extruder might be a completely different hurdle to overcome

So I just feed my tpu outside of the ams in order not to cause any headaches

What I’d really like to see is the ability to pause the print, do a filament swap and resume without issue

But the single extruder still may cause purging issues on the swap of a single print
Dual extruders would be the answer to perform such magic, maybe in the future BL will offer multiple extruders so we don’t have issues printing completely different filaments on a single print :thinking:

I have been championing this for a while. A Bambu IDEX printer with AMS would be the bees knees - like the Snapmaker J1 and Bambu X1C had a baby.


Or get a prusa XL in the full upgrade kit for 5 tools on the toolchanger.

Still vaporware, plus double the cost after the tool changers.

I think IDEX with AMS would offer a better compromise of price vs function - 1 extruder can be printing while the other is actively changing material if needed. Plus you open up the higher speed options of dual material only printing scenarios that IDEX already offers today. The J1 looks to have some slick answers to calibrating nozzle distance which is traditionally an issue with IDEX. My other printer is a Bibo 2 which is a fixed head dual extruder, and I was very much split between the J1 and the X1C.

1 Like

Actually the first printers have arrived at people a day or two ago, so at least the version without the tool changer isn’t vaporware any longer. Took them long enough.
And yes, its quite a bit more expensive, but has a bigger build plate. And we have no idea what a X1C with IDEX and two AMS hubs would cost, but I doubt it would be below 2k.

1 Like

Sure - the whole thing is in our imaginations at this point - and Bambu would have some interesting issues to solution for like purge operations given the IDEX heads share a gantry.

IF anything like this were planned or in the works, it could really keep costs down for existing customers if the current gen AMS were compatible.

Having shed more than my share of blood from my forehead on the edge of the desk trying to print TPU on multiple Bowden Tube feed printers (and Bowden/Direct Drive hybrids), I’ll say the physics involved in making it work wouldn’t offset the cost of the design challenges.

There are several inherent problems with TPU, even high shore value that make it virtually a non starter when more than a few inches (or mm :wink:) of feed tube is involved.

The X1C and P1P are direct drive printers and can print TPU fine.

The AMS is a long tubed feed system. There are a couple “choke points” in the feed path that already offer issues for “normal” filaments - for example:
Exhibit A: Printables
and some prefer this Exhibit B:

The Filament Buffer on the back also has been the source of some problems with certain filaments. That assembly alone would require replacement or complete redesign to deal with a flex filament as well as something stiff like CF filled ones. You’d need a dual spring assembly, one for stiff, one for soft.

Those issues aside, the simple fact is that pushing TPU through a long tube is like trying to push the end of a 100 foot rope on the ground from one end and expect it to move. It won’t, period. All the wishing in the world won’t change the physics of it.

If you use narrower PTFE tube like Capricorn (I have a bunch on different printers) you run the risk of having high friction or complete failure to feed if a filament is a bit too large, so BL chose larger diameter feed tubes. It reduces friction and reduces jams. But you are also going through, by my count 12 places when the filament switches through a tube or gear feed.

If you think you can get TPU through that torture chamber of horrors I’d wager good money at odds you won’t!

Lest you think I’m mocking you or making fun of you, trust me, I’m far from doing that I love the idea. But I also love the idea of sitting in orbit around Jupiter … :grin: I just think, having wrestled this monkey before, your idea is a non starter. Truly it’s sad too. :cry:

If they pulled that off you’d have to fight me in line to buy it!


1 Like

I’m no expert (yet) and just my 2cts but I’m thinking of coated TPU, where a thin coating gives the filament rigidness (enough for feeding) and gets mechanically stripped off near entering the head. I just have haven’t yet figured out what to do with the coating after it gets stripped off. Would need a whole waste disposal return feed I guess.