An electromechanical actuator (“EMA”) may comprise a ball screw having at least one tab extending from an inner surface thereof and/or an actuator drive unit (“ADU”) housing that interfaces with the at least one tab. The bail screw may include three tabs extending from the inner surface thereof. An outer surface of the ball screw may be threaded to mate with a threaded portion of an inner surface of the ADU housing, and/or the ADU housing may interface with the at least one tab, and the ball screw may be rotated to translate a ball nut situated concentrically over ball screw axially. The ADU housing may include a gear train assembly having a carrier plate, wherein the carrier plate includes at least one receptacle.