This filament spool adapter was designed to help the filament spool to rotate more smoothly on a rod with a 20mm diameter.  It consists of two parts which are held together by a pair of M4 x 40mm bolts. It was designed for the eSun filament spool but it should also fit other spools which have a center hole diameter of 53mm.

Supports are not required but it will be necessary to drill through a thin sacrificial layer which is supporting the smaller holes.