Trying to print TPU with no success

Flagship K Series
1

Hi all,
I’m trying to print TPU, but failed miserably. I have a spool of Ninyaflex, which I tried to print on a CTC printer, and it did not work. So I thought the K1 is much better, It seems not. I was a bit suspicious when the extruding (button I mean) produced only a small amount of material and sometimes nothing. So I sliced a simple model (closed tube) with the standard generic TPU profile, and this is what I got, after about 10 minutes printing time:

IMG_TPU
IMG_TPU1920×1440 222 KB

Printing PETG with the same parameters looks like that, after 1 minute:

IMG_PETG
IMG_PETG1920×1440 363 KB

Should I use a bigger nozzle (0.6 mm), or is this TPU just too soft and unprintable? I don’t know the Shore hardness, and I also don’t know what is available.

Regards,
Hans

2

TPU 95A is the standard TPU available, you can get softer. Shouldn’t need a bigger nozzle, I print TPU with 0.4mm on all my printers. Yours looks like flowrate too low and Z offset too high. Have you tried the textured side of the build plate? Might have success with that first.

3

I went down this rabbit hole when I had to make some orthotics for my dog,
You want to feed TPU with minimum resistance. Most folks opt for a spool holder directly above the machine, eliminating the drag from the tube and run-out sensor.
Speed should be down in the 40-60 range, if the extruder pulls too hard, that thins the filament and the teeth can’t grab it → clog
Hope it helps!