Having trouble printing TPU 85A

Bambu Lab P1 Series Troubleshooting
1

So I recently got some spools of TPU 85A and as the title suggests I’m having trouble getting it to print right. Here is what I want to print:

having-trouble-printing-with-tpu-85a-v0-by8a6g59tcxe1
having-trouble-printing-with-tpu-85a-v0-by8a6g59tcxe11080×1440 184 KB

This is an attachment for my vacuum cleaner that will allow the vacuum to reach into narrow spaces like windowsills.

So I dried the filament for 8 hours in my SUNLU S4, I loaded the 0.6 nozzle into the printer (a P1S), I calibrated it and then I tried to print. But the stupid TPU 85A just does not want to cooperate. The first third or so of the main segment prints well, but then the left wall peels away from the other layers, ruining the part.

This is the best I can amange right now:

r/BambuLab - Having trouble printing with TPU 85A

Here is an image of my setup if that helps:

r/BambuLab - Having trouble printing with TPU 85A

So what am I doing wrong? I’ve tried the following:

  • Made the part thicker in Bambu Studio
  • Turned off the part cooling fan
  • Setting the infill to 100% to allow for a solid surface for more filament

Any help would be appreciated before I tear my hair out.

2

Slow and steady, perhaps with a slightly higher print temp…
The stuff is very soft, so I doubt it can print fast and any tiny issue along the way will ruin things.
You TPU does not bond properly…

3

If you are able to, place the spool above the printer with as little friction as possible:

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17458261044487335950636583818133562×750 101 KB

The core-xy movement is now jerking on the spool a lot and the filament is entering at a 90 degree corner. I know you want to keep the filament dry but having it not feed through the exit hole will also reduce drag. Any drag will impact your results and when the tension becomes higher the diameter of the filament shrinks resulting in under extrusion if it extrudes at all

4

In the picture you posted, are you mostly unhappy with the performance of the overhang? Because that honestly looks like a section that would be super difficult to get done cleanly. Or are you saying the missing section is supposed to look like the render above and the gapping holes are the problem?

Also, when trying to work on this problem, I noticed the 85A profile was on the Bambu list, but I couldn’t select it. Were you able to select the 85A profile?