I have several spools of filament that are smaller diameter than the common plastic 1Kg. All of the spool adapters that I could find for the Bambu Lab AMS are either for 0.5Kg small spools, or rims for cardboard spools. So far, cardboard spools have worked for me in the AMS as long as they are not dented/damaged around the rim. However, some of the more recent spools are slightly smaller diameter (7-5/8", 194mm) than what used to be standard and they drag in the bottom of the AMS causing winding problems. I wanted a simple solution and came up with this.

This has worked for me for undersize spools from JAYO and SUNLU. I am sure there are many others

1. Print in the orientation shown with full supports.
2. Pop the back roller out of the AMS
3. Insert the adapter with the word "BACK" in the back ;)
4. Re-insert the roller

Enjoy!

Update 3-14-2024: The original model has very close tolerance to the roller surface and may rub on the roller if the print quality is poor, so I have posted a version 2 that gives more clearance.