[mgarciah]

There are may be several reasons why, English is not my native language but Ill try to explain. first be sure to adjust the ATV (full servo deflection without jamming the links) for the rudder, second, the neutral position for main blades are when they are at zero degrees, BUT neutral position for rudder blades is NOT zero degrees, when you hover you must apply some rudder input in order to cancel the torque from the main blades (this is the Gyro job), ok, that rudder blades position when the heli hovers and stays straight will be your rudder blades neutral position, when you have this setted,this means that you will have 90 degrees between links and servo arm, you will have full throw either way, so you can achieve the maximun blade deflection and consecuently equal spining rudder force.

To find the neutral rudder blades position you must hover your Heli with the Gyro in RATE mode, hover it and adjust with the rudder trim until the tail holds straight, leaves the trim right there and land the heli, leave the stick alone and there you will have your blade rudder neutral position, now the most important part... without changing the blade angle holding the rudder link recenter the servo arm position.

I hope you could understand this and may help with your problem.