The file 'Filament Spool Adapter 12mm Shaft 3D Printer Model' is (stl) file type, size is 213.5KB.
The hub is 12mm, so any tube or shaft under that (.5") should fit. The steps fit all spool types I had so far. Use M3 threaded shafts to connect both sides. Use whatever leftovers you have - no use wasting good filament on a spool adapter. Even a stylish artefact such as mine ;-)
Adapter-12mm_bogoframe.stl | 546.0KB |