I printed out the TPU components (my first TPU print) for the HULA Feet, and I noticed gaps at some points. This is where the nozzle lifted up and travelled, then started printing again, seems it started moving before the TPU was flowing at that spot.
What setting would I modify to tune for this?
slicing error. see if your wall generator is arachane or classic. choose the other one and see if it helps by checking the line preview, see if the walls are generated correctly with the preview.
Tried printing again. Seems to be something in the way it is printing. Possibly the STL is not great, or the way the slicer is making the g-code. It does the complete outer part in a single continuous pass, but the inner ring it breaks up into 4 individual segments, not a continuous pass.
Tried messing with a few settings with no luck. Here is what the G-Code kinda looks like before it starts doing the outer part. The outer part is done in one pass, without lifting the nozzle, but the inner ring is being connected with small segments.
Is this filament profile modified? I’m guessing the P.A. number is incorrectly set. But it could be related to the wall thickness, as others have alluded to.
Currently using the default Generic TPU settings. None of them have been modified.
What is the wall thickness of that section?
It has been ages since I printed my Hula’s but remember having trouble with the springs.
Slowing the print a lot greatly improved the quality. Unfortunately, I can not remember if I did this through a reduced flow value or directly reducing speeds.
Of course, I also dried the hell out of the roll and printed from the rear spool (TPU 95A). I think that I used Arachne but don’t hold me to it.
For the feet, I lowered them below the print plate to result in a 0.4mm thick sole. Due to my background in Vibration control, my intention was to ensure performance by limiting their function to anti-slip. I am ery happy with them under my X1C 
Only a single wall layer. Printing with 0.4mm nozzle and 0.2 layer height. My infill/wall overlap is set to 15%. Maybe increasing that will help.
Outer wall is set to 0.42 and inner wall 0.45.
The quality of the print seems great, and I did dry the filament for 12hrs before. I have 0 stringing.
These Hula Feet are for the Voron 2.4r2 350 StealthChanger I’m currently building.
Addendum: I think I also tried to reduce retracts by using concentric wherever possible and I certainly enabled “wipe on retract”
I haven’t downloaded the part but I assume it is 0.42mm which will not have any room for variance. BTW, did you notice this in the PDF manual for the HULA Feet?
IMPORTANT
Please calibrate Filament Flow Dynamic ( or Pressure Advance) Very important for TPU printing. My PA value for 95A TPU is K=0.158, it is a ballpark figure to use as a starting point.
This would suggest you may need to run a PA test and get a good value because there is no room for variance in the wall thickness.
The file I downloaded consists of two parts: the ring and the loops.
You can try right click and Merge and set the line width to 0.48 for all and see if that works.
The other option is to cad it as one part design.
Not sure I would use the author’s setting directly, but you set the K factor by running the calibration (recommended, run the automatic calibration), or through the manual calibration. I believe you can also use the JSON profile and edit the profile directly from the JSON file, but never tried that.
So I just tried adding the STL, rather than using the 3MF file from the repo, and the slicer behaves differently. It does a complete inner circle first, then does the petals. Going to try this again.
Edit: Printing way better already. Issue appears to be the 3MF and Slicer are not getting along.
Maybe they Merge the 3MF file already
Next up to try, and may be even better for this application, this eSUN TPE 83a I just received.
The softer the TPU, the more sensitive it is to friction. Even TPU 95A HF is sensitive enough to be affected by issues such as longer or non-linear PTFE tubes. When strength is more important than appearance, I opt for random seam placement.
