Universal Bowden Dual Extrusion with 1 Stepper, 1 Nozzle, and No firmware modification

This is a dual extrusion system for any Bowden 3D printer. Using this will not require any firmware changes to the 3D printer itself, however, it will require an Arduino capable of running 1 servo motor. This is different from the existing 1 stepper- 1 nozzle solutions as it actually has 2 extruders bodies - each with adjustable idler tension – and switches between them. This allows for a much finer control over the extruders than existing solutions allow as those rely on a servo motor to provid