A surgical instrument is provided that includes a first input mechanism having axial slots formed in a periphery and a second input mechanism having helical slots formed in a surface. The instrument also includes an insert having pins extending from a surface thereof, the insert coupled to the second input mechanism such that the one or more pins extend into the helical slots, and a surgical device coupled to an end. The surgical device is moved in a first degree of freedom in response to a mechanical driving force applied to both the first input mechanism and the second input mechanism, respectively, and the surgical device is moved in a second degree of freedom in response to a mechanical driving force applied to the second input mechanism while the first input mechanism is held stationary.