About this 3D model
Print out the three holders. I use a 1" x 48" wooden dowel like this one: https://www.homedepot.com/p/1-in-x-48-in-Raw-Wood-Round-Dowel-HDDH148/203360196 one 4 foot dowel can hold over 30 lbs of filament! built specifically for 1kg spools, but will work on smaller ones too.