Spool axle for power drill winding

I designed this to allow me to wind filament onto a spool using an electric drill or screwdriver. I used an M8 coach bolt and an M8 nut to attach the wedges to the spool and then put the end of the bolt into my drill.

The spool_wedge_square.stl file has a recess for the coach bolt head and the spool_wedge_nut.stl file has a recess for an M8 nut. You could also use some M8 threaded rod with two nuts or an M8 bolt with a hexagonal head.