Open Hardware Stepper Shaft Knob (With An Attitude)

I _may_ have gone a little bit overboard with this knob, but in any case, here it is.

Its use is the same as my earlier Stepper Shaft Key (thing #567784), and the OpenSCAD source code is based on my earlier Open Hardware LCD Controller Knob (thing #555370).

Imnsho it looks good on Marty Rice's awesome direct drive extruder (thing # 501755), but it can of course be used with any direct drive extruder with a stepper with an accessible D-shaped shaft.

I have included the OpenSCAD source so