I'd like to find out how gyros work. Do they use a gimbal rotated by a small electric motor, or are they solid state? How many axies do they have i.e. pitch, roll, yaw? How does the gyro interface with the receiver? Can a gyro be used to control something other than a tail rotor i.e. ailerons, elevator, rudder on a fixed wing craft? I know that gain is used to control the sensativity (control theory), but what else should I know about it?

Maybe there is some online resource where I can read about them, or you can explain it to me here?

Thanks,
-Q.