I know im missing some cogs, but am i the only one?
I mislead BS and the AMS thinking that my Sunlu Silk TPU is TPU for AMS… what could go wrong?
Deffo needs some calibration but, am i the only one??
Unfortunately attempt no. 1 was a failure.
The volumetric flow was set to 18mm^3/s so it ended up having a clog half way during print.
And for some reason it was printing with cool plate setting while on textured pei.
Attempt two:
Replicated the same settings from my Sunlu profile for TPU.
VF: 7mm^3/s Flow Rate: 1 retraction 0.4@ 30mm/s
Dont see any issues with the AMS so far…
Attempt no. 2 failed as well
From what i can gather, the main extruder goes nuts while the AMS idles, resulting in a block somewhere inside the toolhead.
The line width was indeed 0.12mm on the first two attempts.
Switched to 0.28mm for attempt no.3
Yeah, I tried inserting TPU on a not AMS Lite…got stuck in the AMS and I had to disassemble it. Learned my lesson.
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My guess is that you’re going to find it more trouble than it’s worth and it will have a continual run of problems. If you’re using a soft TPU it’s just going to stretch too much trying to run it through there. Remember that the AMS Lite gears don’t feed the filament past initial load. After that they just work as a passive odometer and leave all the pulling to the extruder gear. And pulling the TPU through that extra gear is just one more step to cause stretching. In fact, if you watch the extruder gear spinner and the filament spool, you’ll likely see that there are many times when the extruder is pulling but the spool isn’t moving - then once the TPU has stretched enough the spool will move and catch it all up, leaving it constantly going between feeding too much and too little into the extruder.
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But, my dear sir, this is where you are mistaken.
As i was observing the behaviour of this wonderful cog aggregate, i have came to notice that while the extruder is trying to extrude and retract, being the nature of the TPU strand, it does not push the filament and the AMS is not intelligent enough to pull.
Hence, the extruder is grinding on the filament without any fortune to retract it. And more even, as the filament is retracted but does not have anywhere to go, the end becomes severed hence no more extrusion.
But, if my observation is correct this can be fixed with a simple yet very effective discombobulating trick.
Allow me to demonstrate…
I bet many of us learned the hard way not to do this. I’ve read that it can be done with modifications but the modifications seem daunting.
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So…
Attempt no.3 was quasi successful, as the printer printed til some point but turns out there is no material i can print with to make it work without human intervention.
I figured that if it prints flawlessly as external filament, it shouldnt have any issue with printing from AMS if there was enough room to wiggle without involving the AMS in the long run.
Once it started printing i have disconnected the PTFE tube from the AMS and left the tube to act as a buffer. It was held in place by the other tubes with a velcro strap.
The whole process was ok but the AMS stands for Automatic Material System, so this procedure defeats the purpose.
The AMS had minor interaction so i dont think it would suffer in the long run but there is either need for a wider PTFE tube in which the TPU to play in or a mechanism to act as a buffer between the PTFE and the AMS.
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Wouldn’t the best solution be to use the new TPU for AMS filament sold by Bambu? Its ever so slightly different from the regular TPU, but it doesn’t clog either the AMS or AMS Lite.
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That is a solution, but, the differences are greater than slight.
Both are TPU, I really like the TPU for AMS, but, with one being 68D shore and the other 95A, they are two very different stiffness levels.
Their use cases can differ greatly.
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I live in Cyprus.Delivery is a b…
Also, Sunlu is cheaper.
Sunlu TPU-Silk? Yes, but it isn’t simply TPU. Haven’t been able to find any convincing information on what exactly it is (saw a suggestion somewhere that it may be a TPU/PLA blend, but it’s s far more rigid than 95A TPU and a little less rigid than PETG so it’s no real challenge for the AMS.
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I have this same silk TPU, but haven’t tried it in the AMS. It is definitely harder that the other 95A TPU I have tried.
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Does the packaging have a shore value written on it?
When we talk about 68D & 95A, they are shore values from the shore scale.
i didnt do tpu but i did carbon fiber filled pla that wore all the gears down after printing 10 spools of it for a project.
had to get a new ams 
I thought it was 95A, but reviewing it, it is actually advertised as 98A.
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Yeah, I ran into a problem, where it could work but the AMS is not pushing the TPU far enough, so the extruder isn’t able to grab it and the printer gives out a clog error, possible solutions are, that the AMS would push more filament or, that the AMS would push the filament simultaneously with the extruder grabbing it, which would solve the problem, but I wasn’t able to find the G-code for the AMS, so I could change it to ether push more, or push simultaneously with extruder.
( doing it with Sunlu 95A )
The issue i have encountered is not because the AMS is not pushing the filament.
The actual issue is that the movement of the extruder is back and forth and the AMS is not reacting. Hence the filament is stuck in the extruder and thinned to the point that its not pushed through the nozzle.
Maybe disable retraction or… idk, needs more testing
The AMS Lite will never react to that. The AMS Lite only loads and unloads filament, it does not use its gears to feed it as it’s used nor pull it back when the extruder retracts. Once the filament is loaded, the AMS Lite’s gear just spins freely as the extruder pulls and pushes the filament so that the AMS Lite can act as an odometer to measure/monitor the filament use up until the point it gets the signal to unload the filament. It does not, in any way, help the extruder during printing.
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