Tryna Print Some TPU

I picked up a couple rolls of Overture TPU and it’s lovely stuff — supple and squishy and I really want to use it — but I just can’t get it to print right.

Block printed in Overture TPU with insufficient extruder tension

I tried it first on the Prusa MK3S because flex filaments are supposed to work better with direct-drive than Bowden. It jams. Doesn’t print more than a few minutes before it jams enough that the extruder motor starts skipping steps. I’ve tried Prusa’s TPU profile and slowed it down and slowed retractions way down and tried a third-party profile that reportedly worked for them and tried loosening the extruder tension and tried increasing the extruder tension. Always jams.

It jams so badly that I can’t always even extract the filament with a combination of reversing the extruder motor and pulling firmly on the filament. I’m about to disassemble my extruder for the second time. I don’t want to be good at disassembling and reassembling extruders.

Creality extruder with Overture TPU

So I tried it on the Creality CR-10 Mini and it Just Worked … in spite of the Bowden drive. Oh, the irony.

Except it didn’t really work. Upon even a halfhearted examination, I find that it’s underextruding and the perimeters peel off. I’ve increased the extrusion multiplier up to 1.5 (which, TPU, so maybe not as crazy as it sounds) but it turns out the TPU is just so squishy that the Creality extruder can’t get a grip on it, therefore feeding it at a maximum rate of (Useful / Large Denominator), no matter what the feed/flow rate is.


2 Responses to “Tryna Print Some TPU”

  1. Chris Combs says:

    Higher temp? I think the Prusa profile temps for TPU were too low on my Mk3->Mk3s.

  2. Keith Neufeld says:

    I forgot to mention, I have tried a wide range of temperatures, in 5°C increments, covering the range recommended for the filament.

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