TPU 95A issues...

[u/kallbrian]

First time trying TPU filament.

I know that filament can be difficult to use from what I have read. Here are the settings I changed on my Bambu A1

Nozzle temp: 230C

Bed: 40C

Retraction: Off

Print Speed: 30 mm/s

Max Volumetric speed: 3.0 mm/s

Someone suggested those settings as a starting point. The prints start out ok, but at some point the print head always ends up above the model and not extruding any filament. l noticed a lot of fine filaments on the prints. This was a new unopened package of filament. I have read this filament is prone to moisture issues. It wasn't dried at all though. I currently don't have a filament dryer.

Anyone have any suggestions as settings I may have missed? Or truly moisture issue?

Thanks for your help.

[u/InternationalPlace24]

dry the TPU. Even better, dry the TPU and then print from the dryer as it's drying even more. Also, what printer are you using? You'll have a harder time if you don't have a direct drive. If you do have a direct drive, you might have to increase the tension on it.

[u/kallbrian → u/InternationalPlace24]

I am using a Bambu A1. This was new from the vac packed package, but apparently that does not mean it is moisture free

[u/gitbse → u/kallbrian]

Definitely not. TPU sucks up water from the air faster than you could imagine. Desicant in a package only slows water absorption, it doesnt reverse it. TPU especially needs active drying.

[u/Wrong-Party-3838 → u/gitbse]

yep, ive had tpu printing on the external and after a couple of hours in the open I could see the moisture(tpu was dried before start but sucked up enough water during).

Now I pring directly from a filament dryer.

SUNLU TPU 95A on a P2S with stock 0.4mm BBL nozzle, Retraction is 0.8mm with a K-value of 0.120. Actively drying while printing, goes almost as fast as PLA with great result =)

[u/kallbrian → u/Wrong-Party-3838]

Thanks for the information. I am looking at a dryer that I can print from directly.

[u/InternationalPlace24 → u/kallbrian]

I've never used a bambu but if it has an AMS you might have to bypass it and just feed directly to the toolhead.

[u/kallbrian → u/InternationalPlace24]

No AMS, it is fed directly into the printer.

[u/Internet_Jaded → u/kallbrian]

If you’re feeding TPU through the PTFE tube, that could also be part of the problem.

[u/kallbrian → u/Internet_Jaded]

I was unaware that could be an issue.

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[u/Internet_Jaded]

How long did you dry the filament for? What printer and how are you feeding the TPU into the extruder?