Optimize Extrusion Parameters and Mechanical Feed for TPU 70A

Since TPU 70A is highly prone to buckling, you must adjust your slicer settings and mechanical setup to reduce backpressure and drag:

1. Reduce Print Speed: Set your printing speed to 10–20 mm/s to allow the nozzle to melt the material without creating excessive backpressure.
2. Minimize Retraction: Set retraction distance to 0–1 mm and speed to 15 mm/s to prevent the soft filament from being pulled into the colder zones of the heat break.
3. Adjust Temperature: Increase your hotend temperature to 225°C–240°C to lower the melt viscosity of the TPU.
4. Limit Volumetric Flow: In your slicer, cap the max volumetric flow rate at 1.0–1.5 mm³/s to prevent the extruder from overdriving the hotend.
5. Reduce Spool Drag: Use a bearing-based spool holder to ensure the extruder does not have to fight against mechanical resistance, which causes the filament to stretch and buckle.