Can I run standard TPU through the Bambu AMS?

No. Standard flexible TPU (85A–95A) buckles inside long PTFE paths and wraps around AMS drive gears. Feed standard TPU directly via the external rear spool holder. Only specialized high-durometer "TPU for AMS" can pass through AMS rollers.

What print speeds and retractions work best for TPU on direct-drive toolheads?

Cap volumetric speed to 3.5–6 mm³/s (approx. 30–60mm/s linear speed). Limit retraction to 0.5–1.5mm at 20–30mm/s speed—excessive retraction pulls soft TPU into the thermal neckpiece, causing heat-creep jams.

Do flexible filaments require drying before printing?

Yes. TPU is extremely hygroscopic and absorbs ambient moisture within hours, causing heavy stringing, surface bubbles, and weak welds. Dry TPU at 65°C for 8 to 12 hours prior to printing and feed from a sealed dry box (<15% RH).