Designed to be used with a top mounted spool (I use Footloops Top Mounted Spool Holder).
M4 Bolt and Nut used to secure to the holder and chassis.
Hole prints at a nice size for threading straight onto the bolt.
Avoid untangling of filament as the extruder moves around XY plane.
Simple and quick to print.
The author marked this model as their own original creation.