Hex drill adaptor for generator coil winding

I was building my own version of Tom Stanton's hand cranked generator: https://www.printables.com/model/658157-hand-crank-generator 

My first attempt at winding the coils by hand wasn't pretty, so I designed this part to allow a drill to attach using a 6mm hex bit. Combined with an optical tachometer, this allows fast coil winding with a precise coil count.

I would recommend drilling out a pair of coil templates, plus a single coil stiffener from the original files with a 3mm drill bit. Then use two M3 x 25mm bolts through those parts and into the hex adaptor. It is sized so that the M3 bolts will cut their own thread.. 

I covered my version of this project in the following video: 

Built upon the coil stiffener part to add a 6mm hex drive cutout.