Dual Switching Extruder Servo rotating no ooze

Edit April 30-2018: I have added an adapter for a 40mm fan. Just in case you want to run a quiet Noctua.

Edit Mar 18-2018: Note on Calibration. Due to the angle the hotend clamps are printed the hotend will not move perfectly smoothly to level. It is not necessary to be perfectly aligned. You can enter the nozzle height difference into Marlin Switching extruder.
Edit Feb 4-2018: Added a new Parts cooling Fan for the left side for better clearance.

https://www.youtube.com/watch?v=JipLZppD