Cardboard spool "lazy suzan" stand

When using cardboard spools with plastic core I tried to use lazy suzan stands with ball bearings and my spools kept unwinding.

Then I tried just placing them on a stand like this and in my case this provided just enough friction to avoid uncontrollable filament unwinding, but not too much so extruder on my prusa mini can easily pass the filament forward.

Made the inside empty, but with slopes so it prints without supports. Since this part is never really under load, you can test how low you can go with infill :D

If you find that your spool still turns too easily and unwinds, you can always add a little friction by placing something (e.g. paper cover) between the stand and the spool core.