Spool adapter - refil filament - cardboard - spool

♻️ Reusable Cardboard Spool Adapter – for Filament Refills This adapter is designed to give a second life to empty cardboard filament spools by making them compatible with standard refill coils. A simple and sustainable way to reduce waste in your 3D printing workflow. Unlike many models that rely solely on 3D-printed threads (which tend to wear out over time), this design uses M3 screws for a stronger and more durable assembly. It’s optimized for countersunk screws, but other M3 types work just fine too. You can use either threaded inserts or standard hex nuts, thanks to dedicated slots that provide maximum flexibility. ✅ Compatible with cardboard spools from all brands ✅ Designed for long-term durability and reuse ✅ Recommended to print in ABS – in case you need to dry the filament, it won’t easily deform ⚠️ Note: the center hole might be too small for certain spool holders. A universal version with a wider center hole is already in the works and will be available soon. Also coming s