· Austin Prysock

How to Print TPU on Bambu Lab Printers: Flexible Filament Made Easy

Complete guide to printing TPU and flexible filaments on Bambu Lab X1C, P1S, P2S, A1, and A1 Mini. Speed settings, AMS compatibility, and troubleshooting.

bambu-lab3d-printingtpuflexible

How to Print TPU on Bambu Lab Printers

TPU (thermoplastic polyurethane) is the material you print when you need flexibility — phone cases, drone bumpers, vibration dampeners, gaskets, wheels, and anything that needs to bend without breaking. But it’s also the trickiest material to print on any printer.

Bambu Lab printers handle TPU better than most, but you still need to adjust your approach. Here’s exactly how to do it, from a fleet that prints TPU regularly for custom drone parts.

TPU Basics: What You Need to Know

TPU comes in different hardness levels measured on the Shore scale:

  • 95A — most common, good balance of flexibility and printability. This is what “standard” TPU is.
  • 85A — very soft and flexible, harder to print. Think phone case softness.
  • 98A — stiffer, almost rigid. Easier to print but less flexible.

Start with 95A TPU. It’s the most forgiving and most widely available.

Recommended TPU brands:

Printer Compatibility

X1C and X1E

  • Best Bambu printer for TPU. Direct drive extruder, enclosed chamber, precise calibration.
  • AMS: works but can be finicky. External spool recommended for reliability.

P1S and P2S

  • Good for TPU. Direct drive helps. Enclosed (P1S) is a slight advantage.
  • AMS: same as X1C — works but external spool is more reliable.

A1 and A1 Mini

  • Works fine for 95A TPU. The shorter filament path helps with flexible materials.
  • AMS Lite: NOT recommended for TPU. The feeding mechanism isn’t designed for flexible filament.
  • Use external spool holder.

Critical Settings for TPU

Speed — SLOW DOWN

This is the #1 rule for TPU. Flexible filament buckles and jams if pushed too fast.

Recommended speeds:

  • Outer wall: 20-30mm/s (yes, really)
  • Inner wall: 30-40mm/s
  • Infill: 40-60mm/s
  • First layer: 15-20mm/s
  • Travel: 100-150mm/s (reduce from normal 300-500mm/s)

In Bambu Studio: start with the “Silent” profile and reduce speeds further. Or create a custom TPU profile.

Temperature

Nozzle: 220-235°C (depending on brand)

  • Bambu TPU: 230°C
  • Overture TPU: 220-225°C
  • NinjaFlex: 225-235°C

Bed: 50-60°C

  • Higher bed temps cause TPU to stick TOO well
  • 55°C is the sweet spot for most plates

Retraction — DISABLE OR MINIMIZE

Flexible filament jams when retracted aggressively. The filament compresses instead of retracting cleanly.

Settings:

  • Retraction length: 0-0.5mm (some people disable entirely)
  • Retraction speed: 20mm/s maximum
  • Z hop: disable (adds unnecessary retractions)
  • Wipe: disable

If you get stringing with retraction disabled, increase travel speed instead of adding retraction. Fast travel over TPU strings is better than retracted jams.

Cooling

  • Fan speed: 50-80%
  • First layer fan: 0%
  • Minimum layer time: 10 seconds (TPU needs more cooling time)

Flow Rate

TPU often needs slightly more flow than rigid filaments:

  • Start at 100%
  • If you see gaps between lines: increase to 105-110%
  • If you see over-extrusion: decrease by 2-3%

AMS and TPU: The Truth

Bambu Lab officially supports TPU through the AMS, but here’s the reality:

It works… most of the time. The issues:

  • TPU is grabby — it can stick inside the PTFE tubes
  • Retraction during filament swap can jam
  • The buffer mechanism doesn’t love flexible filament
  • Humid TPU gets MUCH worse

My recommendation: Use external spool for TPU. Mount a spool holder on top of your printer and feed directly into the extruder, bypassing the AMS entirely. This eliminates 90% of TPU feeding issues.

Bambu Lab External Spool Holder — worth every penny for TPU printing.

Build Plate Selection

Smooth PEI: Best for TPU. Good adhesion, easy release when cool.

Textured PEI: Works but TPU can bond permanently if bed is too hot. Use glue stick as release agent.

Cool Plate (PEI-coated): Works for most TPU.

Engineering Plate: Avoid — the rough surface bonds too aggressively with flexible filaments.

Common TPU Problems and Fixes

Problem: Filament jams in the extruder

Cause: Speed too fast, retraction too aggressive, or filament buckling Fix:

  • Reduce print speed to 20mm/s
  • Disable or minimize retraction
  • Check for debris in the extruder gears
  • Make sure filament path is straight (no sharp bends)

Problem: Stringing everywhere

Cause: TPU naturally strings more than rigid filaments Fix:

  • Increase travel speed (150mm/s+)
  • Don’t add retraction to fix strings — it’ll cause jams
  • Post-process with a heat gun (quick, low-heat pass)
  • Accept some stringing — it’s inherent to TPU

Problem: First layer won’t stick

Cause: Bed too hot or too cold, Z offset wrong Fix:

  • Bed temp: 55°C
  • First layer speed: 15mm/s
  • Z offset: slightly lower than PLA (more squish)
  • Clean plate with IPA
  • Use smooth PEI plate

Problem: Walls look wavy/inconsistent

Cause: Speed too fast for the material, causing pressure fluctuations Fix:

  • Reduce ALL speeds by 20%
  • Reduce acceleration
  • Check that the spool feeds smoothly (no tangles)

Problem: Part won’t flex — too rigid

Cause: Too many walls, too much infill, wrong TPU grade Fix:

  • Reduce to 1-2 walls
  • Reduce infill to 10-15%
  • Use gyroid infill pattern (flexes uniformly)
  • Use a softer TPU (85A instead of 95A)

TPU Project Ideas

TPU is perfect for:

  • Phone cases — custom fit, endless designs
  • Drone bumpers/guards — absorbs impact without breaking
  • Vibration dampeners — motor mounts, speaker feet, keyboard pads
  • Gaskets and seals — custom-sized replacements
  • Watch bands — wrist-comfortable flex
  • Shoe insoles — custom orthotic inserts
  • Cable management — flexible clips that snap around cables
  • Pet tags — durable, won’t scratch floors
  • Grip covers — tool handles, game controllers

My TPU Setup

For drone vibration dampeners (my most common TPU print):

  • Printer: X1C (external spool, not AMS)
  • Material: Overture TPU 95A
  • Nozzle: 225°C
  • Bed: 55°C on smooth PEI
  • Speed: 25mm/s outer wall, 40mm/s infill
  • Retraction: 0.3mm at 20mm/s
  • Infill: 20% gyroid
  • Walls: 2
  • Layer height: 0.2mm

These come out flexible enough to absorb vibration but firm enough to hold camera mounts. Print time for a set of 4 dampeners: about 45 minutes at these slow speeds.

More Bambu Lab guides: PETG Printing Guide, Bed Adhesion Guide, Best Filament for Bambu Lab. Premium guides on Ko-fi.