Miss Daisy XXI

This wrist was capable of actuating 7.8 lbs end effector while providing accurate position feedback and maintaining position without excessive current draw through the integration of an absolute encoder and piston actuated locking "comb" which prevented unwanted rotation as a result of the extremely large end effector. As the end effector continued to gain weight through the design process, it was found a high gear ratio on the wrist actuating motor was insufficient to prevent backdriving. As such, a linkage which interfaced with the gear teeth of the wrist allowed a robust mechanism which did not require discrete positions to lock.