Wonky cardboard filament spools have been falling off my TUSH style spool holders, so I designed this stackable horizontal spool holder for them.

Each stacker can hold a standard diameter 1kg spool up to 79mm wide. The rotating column at the front doubles as a filament guide and support for the next stacker up. The 5cm wide Toothy shelf clip helps prevent the stack from drifting sideways on the shelf by meshing with the corresponding teeth on the front of the bottom stacker. The Toothy shelf clip works best between 20cm lengths of my Shelf Clip Filament Rail V2 to uniformly space the stacked spools.

The filament guides require an approximate length of 2.5cm PTFE tube (4mm OD, 2mm ID) to be inserted through the guide hole and through the centre of the plastic pin after it has been clicked into place.

I have added a spacer for Geeetech brand (and other similarly sized) filament spools that have a wider 75mm diameter centre hole. It fits snugly over the main spool holder column, rounded end downwards for a better fit.

No bearings or metal fixings required.

UPDATE: I have swapped out the Toothy Rail and Screw file for a V2 version so that it's compatible with the newly updated Shelf Clip Filament Rail V2