Advance Dual Extruder- retracting head

This is an attempt to improve dual extruder printing.
I added a servo to swing the extruder 10 degree. This allow the unused extruder to be lifted 1-2 mm of the bed.

I used this on my CoreXY printer http://www.thingiverse.com/thing:1183198

I use a small MG90S server to move the extruders.
Running on RAMPS 1.4 Marlin code (testing on older 1.0. and latest 1.1.0-RC3)
servo is connected on port 11 (servo 0 standard port)

The standard M280 Px Sy would move the servo fine but it is near