Vòng carton PolyMaker/Inland cho spool (Cardboard Ring)

Important - resize to 100.75 in Prusaslicer for Inland PLA. This then snaps on around it. This is a simple rim. Print in PETG .25 layer height. You might also try 100.65 resize for a little tighter fit and see which one you prefer.  100.65 is needed for polymaker Polyterra spools.

My feeling is that a better spool solution is to use a center spool system if you can. I moved to this setup instead - https://www.printables.com/model/451919-frictionless-spool-holder-hubs