My cheap e-bay i3 clone broke it's X-axis belt pulley holder.
I couldn't find a already made replacement part that fitted so I decided to try to draw it up in Rhino.
The holes for the bearings are ø8mm with no play and are intended to possible be drilled for exact match. Same with the long M3 bolt for belt tension.
The bearings for this thing is MF 85 ZZ.