As I print more, I end up with empty filament spools that seemed like they still could be useful. So I designed this carousel bearing rig to hold a empty spool to create a caddy of sorts. Just add standard air gun BBs as bearings.

There are two designs, one for the side of the spool that has the middle section inset, and one for the side of the spool that has the middle flush.

I used the inset version to create the tool carousel in the picture. Note the drawer liner material, this is required to keep the tools from slipping when dropped into place.

I will be using another as a air brush carousel.

These could also be used to hold filament if you load your filled spools horizontally.

Since your spools might vary from the ones I used, I included a picture of the simple design that you could reproduce in Fusion 360 in a sketch, then revolve it to create the design. Apply a few fillets as fits your needs.

The retention ring is used to hold it all together. You can just dab a "quick glue" at few spots along the ring and assemble. I also was able to forgo the cement and used black tape around the perimeter, stretching it tight.