Like RepRack, this is a modular, inexpensive, functional, easy to source, mass filament storage system.

Unlike RepRack, it:

• is designed for 20mm OD 17.5mm ID steel tubing
• uses a monolithic printed bracket with integrated pipe clamping, mounted directly to the wall
• includes end caps to protect your spools from the perilous prospect of plummeting to a premature passing

Required Hardware (per Bracket)

• 2x M3x8 machine screws to clamp the pipes
• 2x screws + drywall anchors or other mounting solution. ≤5mm Ø screw thread, ≤10mm Ø countersunk head

Additionally, you'll need a pair of 20mm OD 17.5mm ID pipes in whatever length you wish. Feel free to remix the files if you require different dimensions, both Fusion 360 and STEP files are available.

Printing

I printed the brackets with 4x0.5mm walls, 5 top/bottom layers and 15% infill from PLA and they're plenty strong.

When printing the rod covers or caps run off a test print first to make sure they fit snugly and scale them in XY in your slicer if they don't. They're intended to be a fairly tight friction fit.

Print the rod covers in vase mode with 0.6mm line width.