This is a hub centric feed system for a Polymaker's common and excellent PolyDry box storage. You are only likely to need this if you are printing very stiff filament, like PPA-CF, PPS-CF or PA6-CF.

[https://shop.polymaker.com/products/polydryer?variant=43078550323257](https://shop.polymaker.com/products/polydryer?variant=43078550323257)

I found that very stiff filaments resist unwinding and tend to move around in the drybox, sometimes jamming. When feeding up, the spool will lift off the rollers and lose alignment with the rollers in the box, again, jamming. This adapter uses the PolyDry box roller bearings to mount the spool tightly from the hub, making unrolling smooth, even with very stiff filaments. No extra parts are necessary.

One word of caution, the PolyDryer that this box works with can achieve sustained temperatures of 70c, and PLA will sag at these temps. It is highly recommened that if it will be used with the heated dryer that the parts be printed in PETG, ASA, or better.