This is just a simple spacer for the dandcmckay's AMS lite small spool securing end cap https://makerworld.com/en/models/172018#profileId-193845

I found that this end cap worked very well but it allowed the spool to move from side to side. Sometimes this resulted in the filament being pulled off the spool at an angle, increasing friction.

This is a simple spacer to hold the small spool out near the end of the post so that the filament feeds in a nearly straight line and will never rub against the inside of the spool. It has a wider bottom to increase surface area and act as a washer. I put this against the AMS lite body, you could put it wherever you want. It's not flush fitting, there's some clearance between the AMS lite body and the spool so there shouldn't be any added friction - it's just to give the spool a little nudge back into place if it wanders.

I have two sizes of small spools - JAYO small spools with an ID of 43mm and ERYONE cardboard small spools with an ID of 56mm. I sized it for the ERYONE spools and it's 5mm thick, so it's suitable for any small narrow spool with an ID up to 61mm…that would probably be all of them!

The JAYO spools are 40mm wide, the ERYONE spools are 37mm wide. This spacer is 20mm wide, sized for the JAYO 40mm wide spool. It won't accommodate wider spools than that but it will work for anything narrower.