I Designed this model to help some folks that reached out about various issues regarding the Recyclable spool metal insert touching the spool holder Squeaking caused rough areas on cheaper spool holders. this is an easy-to-insert easy to remove has worked on over 24 hrs printing without falling out. i am working on a screw together design as well but I thought I would put this very basic easy to print one out there first .

2 top and bottom layers 
2 perimeters
5% gyroid infil , I didn't try but lightning would work for this design