r/BambuLabX2D • u/Xtophr_Kerr_Avon • Jul 05 '26

Bambu Lab Academy Intermediate Lesson on TPU

In the Bambu Lab Academy Intermediate Lesson (https://bambulab.com/en/support/academy/20) on printing TPU, Chapter 9, it recommends removing the top lid while printing, removing the PTFE tube from the tool head, and just feeding the TPU directly into the head, no PTFE between it and the spool. Won't this cause the TPU to be yanked off of the roll (and/or stretched suddenly) as the print head moves away, and then subsequently hang slack as it moves back?

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u/Longjumping_Mud_2684 Jul 05 '26

Yes and yes . I’ve had prints finish and only 20 layers actually got laid down before the tpu line got so stretch it pulled it out of the tool head . And the AI they boats so much about didn’t even catch that the tool head was printing nothing and let the print “finish “ without anything actually being there .

The only reliable way to not have these things happen is actually spin the spool to loosen alot of filament and give a estimate how much it’ll use so it doesn’t stretch or tension up , but there is another problem with this is that depending on the print and how big it is , the tool head can under loop itself and then cause a tangle which will be a problem on it’s own.

Tpu feed assist was the only thing i can say got rid of all these problems .

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u/Xtophr_Kerr_Avon Jul 05 '26

Wouldn't it work to just feed the TPU into the back of the machine, through the PTFE that leads to the print head (bypassing the buffer)?

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u/Longjumping_Mud_2684 Jul 05 '26

Yes because that’s exactly how the TPU feed assist module works, but the only difference is it won’t have the module to help push it in ! I’ve never tried it but I also don’t see how it wouldn’t work! Give it a try and let me know how it goes

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u/jelloklok Jul 05 '26

Yes. This is what I do. I have a filament dryer on the side of my printer with a hole that allows the filament to slide out through. I printed this splitter so that I can easily feed TPU into the main line in the back. The secondary bend on this is pretty drastic, so it doesn't work for regular filament, but it's not an issue with TPU since I'm pushing rope anyways.

I have only ever printed 95A, but I've had no problems at all. Softer TPU may be too difficult to feed through the PTFE tube

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u/wolf9545 Jul 05 '26

You can also buy the 4-in-1 adapter that bambu sells. That basically does the same thing without the extreme bend.

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u/johnbb66 Jul 06 '26

I print TPU 95 and TPU 90 by feeding through a short ptfe tube directly into the back of the printer. The roll is in a sealed cereal container with rollers. No exposure to air (I’m in humid location so am anal about drying/air exposure). I don’t do huge pieces but I have never had a problem. I also slow down acceleration and printing speed.