I really like a 42 mm diameter shaft used in the Auto-rewind spool holder (for MMU)
by MartinHoffmann so I made one for this stand. New parts are the shaft, the cap and the nut. All other parts are unchanged. Nuts from the Martin’s design are compatible too.
Filament PM PLA
There is few difficult layers at the bottom of the shaft. If there is any loose filament just clean it with a razor blade. This area only serves as an end point for the cap. You can consider using supports for this area but i believe it is not necessary.