This is a simple Spool Rack inside a standard 50L storage box. I had to design this as there is a lot of humidity where I live and it had started affecting my filament.
This can hold around 8 narrow spools of filament.
It uses a 1'' PVC pipe as the rack.
This is super convenient to use as the rack is on a hinge so that it is easy to replace spools.
I added some de-humidifying bags, and sealed all the holes with silicone sealant.
I've also included some "supports" for the nuts/bolts as the plastic is thin and I wanted to divide the pressure over a larger area than the screw hole itself.
I've included the scad files so that you can make any changes you like.