A control arm assembly for controlling a robot system includes a gimbal that is moveable and rotatable about three axes, and a handle assembly coupled to the gimbal. The handle assembly includes a body portion having a controller disposed therein and a first actuator disposed thereon. The first actuator is mechanically coupled to the controller via a four-bar linkage such that actuation of the first actuator causes mechanical movement of a component of the controller which is converted by the controller into an electrical signal.