Systems and techniques are described for actuating a control surface about a pivot point using variable moments. A bracket having a moment arm is coupled to the pivot point such that the bracket is rotatable about the pivot point to actuate the surface. A power actuator has a shaft coupled to the bracket at a coupling point on the moment arm such that actuation force applied to the shaft results in a moment produced about the pivot point. A linear actuator is configured to adjust the location of the coupling point with respect to the pivot point to thereby changing the moment arm and the moment produced about the pivot point as the bracket rotates. By adjusting the distance between the pivot point and the coupling point, the moments produced about the pivot point can be increased while conserving actuator power.