Center Piece to connect the two sides of a Prusa Spool.

This way, you can use different refills on this spool. 

You need to modify the Prusa Sidepieces: You need to remove the flanges for the cardboard center piece. I choose to lathe it down, but you can do any way you want.

2 Models available: One with holes for M4 thread inserts and one with M4 thread integrated in the 3d Print (maybe not as durable)