Extruder visualizer, reactor style

Just another visualizer for the Prusa i3 MK3S extruder.

You can watch the stepper motor spin clockwise as the extruder works to push the filament out through the nozzle, or anti-clockwise when it retracts.

Not that useful but nice to watch. A short [video here](https://youtu.be/_aWIa1UERIg).

You need eight 8x3mm magnets for this project.
* 4 that you should glue to the extruder attachment part. It is used to be attached to the extruder's front face (it connects to the four screw heads),
* 3 to extend the axis of the extruder throughout the part,
* 1 that you must glue inside the slot beneath the propeller's axis.

Warning: the fuselage must be glued to the extruder attachment. You won't be able to insert the propeller after that. So the propeller with its glued magnet must be enclosed inside the fuselage and thus positioned inside; make sure it freely moves.