IKEA Billy support for filaments spools

As I'm starting to have quite a few filament spools I've decided to find a better storage than stacking them on the floor.

I wanted something simple and cheep, so I bough a quite famous bookshelf, 4 times 2.5m 20mm metallic tubing and a few 4mm/16mm wood screws.

I designed and printed the tubes holders (24 required), cut the tubes (75.5cm).

I'm using bags with silica gel beads to keep away humidity from the filament as much as possible (from 45% to 34% in around 12h hours, I'm curious to see how low it can go).

I'm rather happy with the final result, now I've to fill the gaps in the shelf.

The shelf can store around 65/70 spools of 750g/1kg