TPU Filament Spool Rings

Parts Printed in Fillamentum Flexfill TPU 98A. This was chosen after testing several alternatives:

• ABS / ASA — too rigid; skipped badly on the QIDI Box AMS rollers

• Bambu TPU for AMS — harder than ideal; still skipped across the rollers, though less severely

• NinjaTek Cheetah TPU — eliminated due to its HDT of 49°C @ 0.45 MPa, making it unsuitable for use in a filament dryer

• Fillamentum Flexfill TPU 98A — correct compliance for the rollers, and while no HDT is published, the manufacturer specifies a re-drying temperature of 100°C, confirming it handles the Polymaker Polydryer's maximum setting of 70°C without issue — confirmed over several months of use

The rings are designed to stay on the spool through drying cycles, so there's no need to remove them when re-drying filament.

Print Settings I print at 15mm/s to achieve the softest possible result — refer to the Fillamentum TPU printing guide for full guidance. The outer surfaces have a subtle fuzzy skin texture; the 3MF includes settings that represent the best compromise after testing various fuzzy skin configurations.

Compatibility Fits the QIDI Box AMS and the Bambu AMS2.  Designed for the eSUN cardboard spool and the 1Kg Polymaker cardboard spool.   If I buy any new brands of filament on cardboard spools I will add new models.

Fitting When fitting you need to roll the ring around the edge of the cardboard rim.  Once in place they will provide a flat surface to contact the rollers.

References

• Fillamentum Flexfill TPU 98A — product page

• Fillamentum TPU Flexible Materials — printing guide

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Found this useful? These Spool Rings were developed through quite a few test iterations in different materials. If you want to contribute to the next round of testing for the next project, it’s always appreciated: buymeacoffee.com/ChrisNZL