The file 'Customizable Stackable Spool For Sample Or Leftover Filament 3D Printer Model' is (stl,scad) file type, size is 6.8 MB.
I believe this design is self explanatory. You will need one face plate, one end piece and as many bases you want. Moreover, you can customize the design, making larger or smaller spools.
Update 2019-11-01
I added a 15mm spool base for small samples of filament.
EndPiece.stl |
FacePlate.stl |
Filament_Spool.scad |
Filament_Spool_15mm.stl |
SpoolBase.stl |