An apparatus for operating on tissue comprises an end effector, a shaft assembly, and an interface assembly. The end effector comprises an ultrasonic blade. The shaft assembly includes an articulation section operable to deflect the end effector away from the longitudinal axis. The interface assembly is operable to drive the end effector. The interface assembly comprises a base and a plurality of drive shafts. The base is configured to couple with a dock of a robotic control system. The drive shafts are oriented perpendicular to the longitudinal axis of the shaft assembly. A first drive shaft may be operable to rotate the shaft assembly relative to the base. A second drive shaft may be operable to drive the articulation section. A third drive shaft may be operable to drive a clamping arm to pivot toward the ultrasonic blade.
