Specifically for Polymaker spools. For Overture spools, use - AMS Card Spool Adapter - Overture by Nirin | Download free STL model | Printables.com

Using cardboard spools with the AMS, or on any regular spool holder, produces dust and can block the rollers. The cardboard edges can also fray, causing issues.

By snapping this model onto the cardboard spools, only plastic makes contact with the AMS, or with normal axle spool holders, reducing friction and avoiding issues.

Unlike many of the other ring adapters on here, this works with the current version of the AMS without causing fitment issues, while also being compatible with spool-core dessicant holders such as - Adjustable Spool Holder for Silica Gel / Spool Weight by humebeam | Download free STL model | Printables.com

The fit on these rings is purposely tight, so it wont shift or wobble. It should be sturdy enough to keep the cardboard ring rigid and intact for the life of the spool.

Probably best to print in PETG, as removing it involves some bending and if you're not careful it may snap the ring. I've also printed in PLA+ with good results.

Let me know if you have any issues and I'll update/fix!