Parametric Stepper Motor Crank for 1/4" or 6.25mm shaft

thingiverse

I wanted a stepper motor crank for manually moving the steppers (when unpowered) but my motors have a 1/4" shaft so I designed my own crank. The shaft diameter is parametric (along with the other values) so it should be adaptable to other sizes. The size is perfect for use with a NEMA 23 motor but can be changed. I used an M3-0.5 16mm pan head machine screw and nut to secure the crank on the shaft and an additional M3-0.5 16mm pan head machine screw with washers threaded into the handle. You might need to tap the handle but I was able to directly thread the M3 screw into the handle.