Filament spool

For those with not that big printer surfaces (mine is 15cm x 15cm x 22cm), I made this filament spool, with the intention also to add some anti-slip tips at the bottom. I found some online with a plane base on the sides, but those didn't work for my filament. And the ones that works for the cartridge were too big for my machine. The only one that I found and that I've been using for a few months is the Simple Filament Spool (v3.2), but the rounded bases didn't work for me.

Also I added a bolt and nuts system to prevent the sides from falling when you move the cartridge around.

Hope this helps those with small printers as well as those with larger printers and slippery surfaces.