Narrow Spool Holder/Filament Spindle for Cocoon Create Model Maker (Wanhao/Monoprice i3 Mini)

I bought a 600g roll of Flashforge PLA and found the hole in the spool too narrow to fit on the stock spool holder.

This is a direct replacement that solves the issue.

Updated version 17/02/2019 - added a slope at the narrow end for better printability (_fixed version)