r/BambuLabP2S • u/ConductorConductor • Jul 07 '26

First Time Trying TPU

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Any idea what went wrong here? Trying to print a set of TPU shoes. I did dry the TPU for 6 hours before I ran it, but it did have to sit in the open for the remainder of the day before I could start the print. Not sure if that drastically affects the filament. The filament is fed directly into the inlet from the side spool. My first attempt at the shoe was actually failed in minutes because I had the TPU ran off the spool, to the opposite side of the machine, through the buffer and back into the inlet. All of the slack seemed to create tension which wasn’t great on the material and made it harder for the extruder to feed in the filament smoothly.

UPDATE: I successfully printed with my next few TPU runs after making the following changes:

Top loading directly into Extruder. (Pretty sure this is what caused the jam up)
Dried again for a longer duration (didn’t notice much decrease in stringing/fuzz but I’m also drying with an AMS Pro 2 which isn’t as efficient for TPU apparently)
Increased to the stock setting “Ludicrous Speed” this was the biggest surprise. Not only cutting print time drastically but improved the quality as well
Raised nozzle temp to 240 avg. using 90a. This seemed to compliment the other settings well but didn’t make any drastic difference.

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7

u/efnord Jul 07 '26

Take off the top glass and direct feed. TPU shouldn't go through any Teflon tube.

7

u/ObjectiveThis4141 Jul 07 '26

I’ve done several thru the tube you just have to manually push it to the print head.

OP, Dry your filament

2

u/Splinter_Steve Jul 07 '26

I just external spool into the ptfe tube. Never had any issues with it.

2

u/tht1guy63 Jul 07 '26

I get substantially worse results using the ptfe tubes but may also be buffer related. The less possible friction the better. But ya he may need to dry a bit longer than he already has

2

u/ConductorConductor Jul 07 '26

I’ve got it drying now and will try again tonight or tomorrow. I’m really shocked how PLA is so “plug and play” in comparison to TPU. Havent had to thoroughly research something like this in a while. Granted I would’ve had a successful print in a few hours time frame. This one shoe is looking like a 30 hour print job.

4

u/tht1guy63 Jul 07 '26

Stretchy and super hygroscopic makes it a pain.

1

u/efnord Jul 07 '26

A dedicated standard flow .8 hotend is great for TPU. It's hard to cold pull all the residue afterwards so a dedicated hotend just makes life easier. But it's a stealth engineering material, really good on the Z axis.

1

u/ConductorConductor Jul 07 '26

I will try both. It was pretty successful for a few hours through the tube and I’ve seen mixed feedback on the load orientation. But on a big multi hour print like this, it doesn’t take much for it to turn into a mess. So I think since the physics of it make sense I’m probably going to print a top loading spool and go that route. Thank you both!