Seeong as how I had some long 5/16" bolts and 608 skate bearings around…
Just another filament spool holder
Also using some 12mm plywood, but my last few had 3D printed cores instead of the milled plywood. The new cores are conical, with the base a bit larger then the opening of the spool, holding the 608 bearings. Then the nut is spun on tight enough to clamp them to the spool.