Eliminate TPU Stringing on the Bambulab A1 Mini $199 3D Printer

Introduction

This tutorial covers how to eliminate stringing when printing flexible TPU using the Bambulab A1 Mini 3D printer. By adjusting specific settings and understanding retraction, you can achieve cleaner prints. This guide provides step-by-step instructions based on Chuck's experiences with flexible TPU and his successful adjustments.

Step 1: Load the TPU Filament

• Begin by selecting the filament option on your Bambulab A1 Mini.
• Choose the "Load" function to start feeding the filament.
• Push the TPU filament all the way into the nozzle until it is securely grabbed and starts feeding out.

Step 2: Prepare Your Model in Bamboo Studio

• Load your model, such as the flexible octopus, into Bamboo Studio.
• Select "Generic TPU" from the filament list.
• Click the edit button to access settings.
  • Ensure the Max Volumetric Speed is set appropriately for TPU to control the print speed.
• Verify that the temperatures for printing are correct.

Step 3: Adjust Retraction Settings

• Initial retraction settings may lead to stringing, so it's essential to adjust them.
• Conduct a test to measure filament compression:
  • Use a setup with an extruder and PTFE tubing to push filament and measure the length compressed.
  • Record the compression measurement (e.g., 7 mm).
• Set your retraction distance in Bamboo Studio:
  • Change the default retraction from 0.4 mm to at least 3 mm based on your test results.
  • For optimal results, consider increasing to the measured 7 mm.

Step 4: Print and Evaluate

• Slice your model and start the printing process.
• Observe the print closely:
  • After printing, examine the results for stringing.
  • Compare prints on different backgrounds (light vs. black) to better see stringing.

Step 5: Fine-Tune Settings

• If stringing persists, continue adjusting the retraction settings:
  • Test retraction values incrementally (e.g., increase from 4 mm to the optimal 7 mm).
• Print again and check for improvements.

Conclusion

By following these steps, you can significantly reduce or eliminate stringing when printing with flexible TPU on the Bambulab A1 Mini. Key adjustments include loading the filament correctly, optimizing settings in Bamboo Studio, and experimenting with retraction distances. After implementing these changes, you should see cleaner prints with less stringing, enhancing the quality of your 3D projects. For further improvements, consider exploring different TPU brands or printer settings. Happy printing!