An apparatus includes a body, a shaft assembly, an articulation section, an end effector, an articulation connector, and an articulation drive assembly. The shaft assembly extends distally from the body. The end effector is connected to the articulation section such that the end effector is configured to deflect relative to the longitudinal axis of the shaft assembly. The articulation connector is configured to translate relative to the shaft assembly to deflect the end effector relative to the longitudinal axis. The articulation drive assembly is configured to translate the articulation connector relative to the shaft assembly. The articulation drive assembly includes a rotatable housing and a first lead screw assembly. The first lead screw assembly includes a first half and a second half. The first lead screw assembly is slidably coupled with the shaft assembly and is configured to translate in response to rotation of the rotatable housing.
