Filament Hub Expander

Print two C hub expanders (3.090" ID) on their sides using 10% honeycomb fill.  Print 4 Pins standing up.  The pins slide right into the holes.  Get an empty filament hub and sandwich it between the two hub expanders with pins in the holes.  You may want to glue it together, but I didn't have to.  

Also had to print the filament hub internal (ID 0.936", OD 2.85") to increase the diameter of the Prusa filament spool holder to match the hub size.   Press fit the filament hub into the outside of the Prusa spool holder.  Make sure it's the right size for you, because once you press fit it in, it's not coming out easily.