There's alternative to the common arrangement of a motor per blade, like the http://curtisyoungblood.com/V2/products/quadcopters/stingray-500 http://curtisyoung

There's alternative to the common arrangement of a motor per blade, like the http://curtisyoungblood.com/V2/products/quadcopters/stingray-500 http://curtisyoungblood.com/V2/products/quadcopters/stingray... - one motor, variable pitch. It's clearly more complex, but you gain agility, motor efficiency and it seem to give a better running time.