I haven’t gotten ahold of a AMS HT yet but it seems like printing with 85A TPU is going to be a little awkward. I’m thinking there probably should also be a silicone access hole on the front of the AMS HT in addition to the one on the back.
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Yeah… I really push back on the folks that think this is normal. This is the old normal, someone needs to usher in a new world of TPU printing. Also… lets be real, the H2D is probably the best printer to use for mixing TPU and other filaments, so why should this standout feature be so tedious? Plain and simple… Bambu punted the can down the road.
For me… it’s not SO bad, because I just leave TPU on the right nozzle indefinitely. But I imagine those with two AMS’s will be annoyed with dealing with the limits.
I said it’s not a big deal for me, but that isn’t really true. I have some 85A but forgot you needed to use a 0.6mm nozzle, so it’s just useless until I buy a couple of 0.6mm hot-ends. Again, not the biggest deal, but the limitations on a machine that is so tied to multiple filament printing (with TPU being the most likely used second filament) just doesn’t make sense to me. But it’s a great printer otherwise, so I’ll forgive the oversight/design choices.
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With my experimenting on the H2D, I think most of the new, interesting ideas are going to be in using TPU. In many ways the H2D seems to be made for printing TPU but feeding them seems like an afterthought.
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You cant do much to optimize the H2D for 85A as its so soft, so on all printers you have to feed it directly into the extruder bypassing the PTFE tube. You cant blame the printer for it, its not a design oversight or anything like that, its just a fact of printing with such soft material. You dont need to use the HT unless its a super long print. There are a few good models on MW to hold the spool for 85A, Im using the first one.
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I don’t agree. It definitely would have needed to be a priority from day one to make any significant headway. As well, it likely would have cost more. Personally, I believe the design choices were biased around keeping the status quo. But it’s clear, they figured out what the limitations were, and rigged up some workarounds to make it work consistently and moved on.
I can agree they are doing no worse than anyone else. If that is your argument, you’ll get no dispute from me. But I do think they took the easy way out on this problem, basically kicking the can down the road for someone else to make headway.
Im sure it was a low priority as its not a common material to print with for most people.
Are you aware of another printer with better implementation for 85A?
Agreed. I’m sure it was given a lower priority, assuming it wouldn’t be commonly used. But that would be an oversight for a printer that was designed to blend hard and soft materials in a single print.
No, and that’s what I meant in the previous comment about not doing worse than anyone else. But no one else is making claims like Bambu did with multi-material.
Personally, I’m not looking for a TPU compatible AMS that can use 35D TPU, but I would have expected the filament handling to not be so tedious. It’s also possible the new PTFE tube doesn’t work well with TPU. The larger diameter ID (with pointed contact surfaces for less drag) may also play a part.
TPU for AMS is 68D actually, but yes its quite stiff. Its more like PLA with abrasion resistance/anti scratch properties not a traditional flexible TPE.
I dont think the 85A would feed through the star shaped PTFE either as its too soft, but there was some mention of bambu working on a better solution for 85A so we will see if they come up with something eventually.
Those star shaped tubes are prototypes that CNC kitchen got by mistake, as far as I know they are not being shipped to anyone yet.
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I get where you are coming from, but sometimes kicking the can down the road is the only viable option. The fact that no-one else appears to have solved the problem yet speaks to the difficulties involved & with any such product development there comes a point where you have you stop and get shipping products to start getting a return on the investment.
I guess the only question is whether the concept of multiple material printing was oversold. I would say no more than any other product from pretty much any other company.
Respectfully, I think you guys are possibly over-estimating my annoyance. I don’t think they failed. I don’t feel cheated from their marketing. I just think they punted and didn’t work on this problem (possibly proven by rumor that they are working on a workaround for the workaround, LOL). Again, I’m not looking for a super soft TPU compatible AMS. Just expected the limits to be less intrusive. Having to completely breakdown the filament path between soft and hard filaments is annoying (not to mention having to completely modify the filament path on the super soft filaments). Is it a big deal… no, but will I give them high marks on how it works… NO. It’s a demerit. I’m not giving out participation trophies. I will give them a trophy for going through the hassle of validating what is needed. That is rare, because I’ve not seen a company even do that much. They generally just leave it to you or someone in the community to figure out and share.
It’s still the best printer on the market, but they didn’t do a great job on this aspect. As I said in the first post I made on this, I’m not heavily affected because I dedicated the nozzle to TPU (95A), so it was changed once and will not be changed again (or not very often). But I feel for the others who will need to go back and forth with this set of modifications (and for myself who will need to still modify things for really soft TPUs and support materials). Again, not the end of the world, or a deal breaker for me, but this could be for someone expecting more for the price tag. I think it’s good value for money, but that price tag is a premium product’s price and it’s hard to call these workarounds premium. I couldn’t blame someone for being unhappy with it.
Luckily, I don’t need to use support filaments very often or I’d be more vocal on this, as that would be relatively annoying to have to break down the filament path every few prints.
I’m trying out some ideas for getting 85A to print easier on the H2D but I don’t know what my expectations should be. What’s a small test model to print in 85A TPU that would be challenging but should be possible? Some of the models I’ve been trying are either too easy or are made for stiffer TPU.
If you are following the requirements, I’m under the impression it should be pretty much click go and wait. No real difficulties. Sure, some geometries are tougher than others, but largely I would expect it to just work provided you are not pushing the limits on the profiles, or using moist filaments.
Things that are difficult with TPU include the following:
- Supported structures (difficult to separate)
- Extreme overhangs (slow to solidify)
- Webbing and thin structures like thin hexagon surface grid patterns (lots of stringing)
I started with TPU rubber bands and it handed it with no problems.
For more of a challenge, I tried https://makerworld.com/en/models/667324-tpu-fidget-suction-cup-test-your-tpu but it was supposedly made for A90 TPU and the overhangs seemed to be too much for 85A. Plus it has some thin areas.
I just found this one TPU Blower by Mike JacksonMakerWorld: Download Free 3D Models which looks like might be about right.
Soft TPU only exists in the low-end consumer world. The problem is that a custom extruder geometry would be needed, and it will always be slow.
Actually, I’m glad it can print it at all! Move on.
I am using these two mods to have the TPU path always connected so I can print TPU easily without modifying the printer, highly recommended to everyone.
Also use PLA as support interface layer for easy support removal with TPU.
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Thanks, I made my own similar to the second one you shared and still working on a mount for the PolyDryer Box/AMS HT for soft TPU.
I’ve created a simple guide for feeding TPU into the H2D without having to remove the glass top each time. It’s a little plug that fits in the rear TPU port to protect the silicon along with some cable chain brackets to guide the filament near the center of the cable chain arc. It positions the filament out of the way of everything else that is going on. Seems to work well with what I’ve thrown at it so far. I need to get ahold of some TPU softer than 85A to try out next. https://makerworld.com/en/models/1390124
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Nice model, gave it a like and a download. 
Let us know how it does with 85A. Might be better to just have a pla tube instead of a PTFE one coming into the printer to reduce drag with 85A.
Thanks for the like. I printed one of these https://makerworld.com/en/models/1300424-tpu-blower#profileId-1332648 with 85A using it.
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Yea almost comparing it with PLA-HR from BIQU (Airless Basketball stuff)