An end effector of a surgical tool may include a housing, a jaw support shaft, jaw members, and cam pulleys. The jaw support shaft is mounted to the housing and defines a pivot axis. The jaw members are supported on the jaw support shaft and are pivotable about the pivot axis. Each of the jaw members defines a support shaft slot therethrough and includes a pulley pin and a jaw pin. Each of the jaw members defines a jaw pin slot positioned to receive an opposing one of the jaw pins of the jaw members. The cam pulleys are coupled to the jaw support shaft and the jaw members. The cam pulleys are rotatable about the pivot axis to pivot the jaw members about the jaw support shaft
