I designed this filament spool holder for my OpenBeam KosselPro. The central parts are the 2 cones that run on the cf rod and can be moved on the axis to adapt for different spool sizes. All parts are designed to be assembled by just press fitting them together. Only the cf rod should be glued with epoxy to the holder. Of course the mechanism can be used on different printer models by just designing another holder for the axis.