tail variable pitch for walkera 4-3 or 4G3

I do not know if feasible because of scale

video system (v1)
http://www.dailymotion.com/buho29/video/x6mifd_ac-a-pas-variable_tech

video fly 4-3
http://www.dailymotion.com/buho29/video/x76unl_game-heli-43_tech

Battery frame for zippy 400mAh and rhino 360mAh