Filament Spool Hanger

I designed this hanger device in FreeCad 0.20.1. It fits onto a rectangular tube of an Allen Roth Model #LWS3FS bookcase shelf from Lowes. The tubing measures 10.2mm x 40.3mm. There's enough room to fit up to 10 spools of material on each end of the shelf unit. The design certainly has room for improvement and could be adapted to fit other sizes and shapes. The version I've uploaded is updated a bit after I printed mine. I added the angled cut to the bottom side of the end as well as rounded some corners to remove material and reduce print time. Sliced with Cura 5.2.1. I used tree supports for the two small overhangs.

These will slide down the tube somewhat easily, especially if you bump them. A little grip tape or similar would solve that problem.