Parametric stackable upcycled cardboard cores

2025-11-28 update : added the FreeCad file, for anyone to make his/her own upcycling. The spreadsheet tells it all (in french, sorry). Only two items (cyan-colored) should be changed : the internal diameter and the cardboard thickness.

They come from your filament rolls (especially refills), or duct tape rolls, or… whatever. Those cardboard cores are almost useless by themselves. Here is a way to make them into boxes.

They are

• stackable : two boxes of the same diameter may be stacked one on the other
• linkable : two cores of the same diameter may be linked together to get a “double-height”  (or triple, quadruple…) box.

At the very least, you will need two inserts and two lids. 

If you want to link two cores, print two inserts (one for each core) and a link.

There are currently three sizes, more will be added as I get them (or the relevant data) :

• 76 mm internal diameter, 3 mm thickness. That's the usual (duct, scotch) tape core ;
• 94 mm internal diameter, 2.5 mm thickness. I'm addicted to Rosa3D refill rolls, and it's the core size from those (I took the idea from nakwada's https://www.printables.com/model/983609-stackable-containers-parts-for-rosa3d-refill-core and went from there, re-designing everything) ;
• 102 mm internal diameter, 5.5 mm thickness. I had one FormFutura cardboard roll, ripped the flanks and that's the core I got.

2025-05-12 update : fourth size added, for a 83 mm internal, 3 mm  thickness roll (Elegoo).

Files are named “Couvercle” (top/bottom lid), “Insert” (insert) and “Lien” (link), with added internal diameter and cardboard thickness. For example, Couvercle-76-3.stl is the lid for a 76 mm diameter, 3 mm thickness (usual tape roll). If there is some non-integer dimension, the dot will be replaced by a p : Insert-102-5p5.stl.

If you need other sizes, drop me a message, giving me the internal diameter of the cores, and the cardboard thickness (in millimeters, thanks).