An apparatus is operable to clamp, cut, and staple tissue. The apparatus includes a stapling head assembly, a shaft assembly coupled to the stapling head assembly, and an actuator handle assembly coupled to the shaft assembly. The stapling head assembly is operable to clamp tissue, cut tissue, and staple tissue in response to rotation imparted by a single rotary drive shaft extending through the shaft assembly. The actuator handle assembly includes a motor positioned within a motor housing, a rotation knob, and a selection assembly. The rotation knob is coupled to a proximal end of the motor housing. The rotation knob is configured to translate between a proximal position and a distal position. The selection assembly is operable to select between motorized operation of the apparatus or manual operation of the apparatus, based on the longitudinal position of the rotation knob.