TPU: Flexible Prints Without Jams
TPU is stretchy and durable, but tricky without tuning. Here’s how to avoid jams and spaghetti.
Why TPU?
TPU brings elasticity, grip, and impact resistance. Great for phone cases, RC tires, gaskets, and flexible hinges. Shore hardness varies—95A prints easier than softer 85A.
Extruder Setup
Direct-drive extruders are best. If you have a Bowden setup, keep tube as short as possible. Lower retraction (0.5–1.5 mm), slower speeds (20–30 mm/s), and disable coasting/pressure advance if jams occur.
Slicer Tuning
Enable “avoid crossing perimeters” to reduce travel ooze. Increase flow slightly (102–105%). Keep infill sparse for flexibility. Layer heights of 0.2–0.28 mm balance printability and stretch.
Bed and Adhesion
Most TPUs stick well to PEI or glass with a light glue-stick layer. Bed temp 40–60 °C is plenty. Watch the first layer—TPU squishes easily and can curl at corners if too cold.
Common Issues
Stringing: lower nozzle temp or increase travel speed. Under-extrusion: check filament path for kinks. Blobs: reduce retraction distance further. If jams persist, print a PTFE guide insert for your extruder.