triangular universal wire spool holder

I recently got fed up with the loose spools of wiring material I have lying around, and designed this wire spool holder. I tried making it as universal as possible:

-the triangles can stand on their own, or can be nounted to a board or onto the wall
-they accept almost any dowel size up to 8 mm, including M8 rods
-M8 rods can be fastened with nuts, dowels can be secured with an M3 screw and an inserted M3 nut on top of each triangle.
-fits a standard Prusa i2, and Kossel Mini printbed