EDIT: solution is in the comments. TL;Dr retractions ON and INCREASE speed. Both opposite to common knowledge.

I can't print flexible TPU properly. It's either foamy, inconsistent extrusion or jam city, nothing else. I wasn't able to complete a single print properly in a week and probably 50 tries.

Tried

• 24 hours of active drying
• speeds of 10-30mm/s
• flow rate 1-1.2 (100-130%)
• temps 220-250 (mfg rec is 235-250)
• 0.4 and 0.6 nozzle
• Cura and PrusaSlicer

Direct drive (Biqu H2 V2s) on a well-tuned Ender 3 (no issues with ABS, PETG, even nylon). Part fan off. Printing on PP tape (no adhesion issue).

I can get halfway decent looking print with 250C and a Flow rate of ~140% but it eventually jams anyway. Lower temps give super inconsistent extrusion, nozzle spitting chunks intermittently.

At my wits' end. Any more tips? I don't have any other TPU ATM, may be just shitty filament? It's a cheapo polish F3D Filament TPU 93A. Thanks!