spool holder for 80/20 aluminum extrusion(1" square)

I made a moisture proofing box for 5 spools using 74qt weather tight box from containerstore.com. I needed a spool holder that allowed for each changing of spools inside the box. Also i wanted the holders to be a certain distance from the bottom to have space for silica gel packets. So i designed my own design inspired by dual bearing based design that I saw on thingiverse. This one slides on a 80-20 aluminum extrusion bar and can be easily held in place by tightening 1 screw. Use a 3mm screw to