Glass Fiber Rudder Arm AG309-12

Glass fibre rudder arm, part number AG309-12. Glass-reinforced composite is used here rather than metal because the arm has to be light while still transferring the servo load to the rudder without flexing.

Arm geometry sets the mechanical advantage between the servo and the surface: a longer arm on the rudder side and a shorter one at the servo increases torque at the surface at the cost of travel. On a rudder, where the loads are usually the highest of any surface, that trade is worth making deliberately rather than by accident.

Check the fit on the rudder post and the hole spacing matches the linkage you intend to run.