Abstract: A mechanical control system for moving a controlled device in response to the movement of a universally movable control member, comprises a first ball mounted for universal movement in a first socket; a second ball mounted for universal movement in a second socket, and having one side facing one side of the first ball; the control member being coupled to the opposite side of the first ball; the controlled device being coupled to the opposite side of the second ball; and a connecting stem having a third ball at one end received in a third socket formed in said one side of the first ball, the opposite end of the stem being fixed to said one side of the second ball. The invention is described particularly for controlling a laser beam in accordance with the movement of a joy stick.