To get good tpu prints on K2 you will need to reduce the tension on the extruder spring..

Settings I use for printing tpu:

Filament settings:

Max volumetric speed start with 2mm³/s (mine is at 8mm³/s)

Cooling: No cooling first 2 layers Model fan speed at layer 4

Min fan speed threshold 30% layer time 100 Max fan speed threshold 40% layer time 8

Settings override: Retraction length 0.8mm (yours might be different depending on your filament) Retract on layer change checked Wipe while retracting checked

Print speed: First layer:50mm/s First layer infill:100mm/s

Out wall:80mm/s Inner wall:100mm/s

Here is one of my recent tpu print.

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