Holds Solder Spools with .75" Center hole or print a different size outer rod to support others.
Can be mounted under shelf, on back wall or just left sitting on bench. Needs 2 Miniature Skateboard-Bearings - 8x22x7mm online for about $1.00 each. Knob can be inserted on either side to roll solder back in but must be removed to take solder out of holder. I printed the Knob separately so I could make it 100% infill.
The author hasn't provided the model origin yet.