I see the GY-401 and S9650 are a very popular combo. Although I have no idea what a "digital" servo has to offer over an analog(?) servo.

And although I haven't ever used a CP 3D heli I imagine that the gyro talks to the tail servo and changes of the tail blades so that the tail stays locked in?

Thanks,

Tj.

P.S

Why is it that we can't just use the 4 same servos, why do we need 3 for the swash plate and then a different for the tail?