New version available here
Since most of our 3D printers have their built-in spool holders on the back, where it's least convenient, we designed this to gain 30cm of desk space and to facilitate material change (not mentioning avoiding mucking up the wall behind the printer).
We designed this self centring spool holder, simple to print and holds the spindle firmly in place by the weight of the filament.
We added a clip to hold the spindle in place when the filament is almost all consumed and the motor pull becomes stronger than the weight of the spindle (causing it to be removed it from its axis).
Spindle size 28mm (25mm center)
Max spool radius 12 cm
Max spool width 11.5 cm