A mechanism comprising: a rotary electromechanical actuator; a shaft positioning system coupled to the rotary electromechanical actuator; the shaft positioning system further comprising: an electromagnetic coil ; a shaft coupled to the rotary electromechanical actuator, the shaft moving along a linear axis, the electromagnetic coil being positioned around at least a portion of the shaft such that the electromagnetic coil moves along the linear axis of the shaft , wherein the electromagnetic coil produces a magnetic field when electrical current is applied; a metal housing surrounding at least a portion of the electromagnetic coil, wherein the metal housing moves along the linear axis of the shaft ; a first magnet ; a driving cam coupled to the shaft ; a locking cam ; a spring coupled to the shaft , wherein the spring holds the shaft in a retracted position when the electrical current is applied to the electromagnetic coil , and wherein the electromagnetic coil repels the first magnet when the electrical current is applied; wherein the shaft is placed in a protracted position when the metal housing is in contact with the first magnet , wherein translational motion of the rotary electromechanical actuator is restricted when the shaft is placed in the protracted position; wherein the driving cam and the locking cam engage when the spring expands and pushes the shaft and the driving cam into the protracted position until the metal housing attaches to magnet and thereby selectively locks the movement of the shaft into the protracted position; and wherein the driving cam and locking cam are disengaged when the driving cam is in the retracted position. a rotary electromechanical actuator; a shaft positioning system coupled to the rotary electromechanical actuator; the shaft positioning system further comprising: an electromagnetic coil ; a shaft coupled to the rotary electromechanical actuator, the shaft moving along a linear axis, the electromagnetic coil being positioned around at least a portion of the shaft such that the electromagnetic coil moves along the linear axis of the shaft , wherein the electromagnetic coil produces a magnetic field when electrical current is applied; a metal housing surrounding at least a portion of the electromagnetic coil, wherein the metal housing moves along the linear axis of the shaft ; a first magnet ; a driving cam coupled to the shaft ; a locking cam ; a spring coupled to the shaft , wherein the spring holds the shaft in a retracted position when the electrical current is applied to the electromagnetic coil , and wherein the electromagnetic coil repels the first magnet when the electrical current is applied; wherein the shaft is placed in a protracted position when the metal housing is in contact with the first magnet , wherein translational motion of the rotary electromechanical actuator is restricted when the shaft is placed in the protracted position; wherein the driving cam and the locking cam engage when the spring expands and pushes the shaft and the driving cam into the protracted position until the metal housing attaches to magnet and thereby selectively locks the movement of the shaft into the protracted position; and wherein the driving cam and locking cam are disengaged when the driving cam is in the retracted position. <EOS>