Justin Bram's "Bulb-O-Matic"
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Bulb-O-Matic

    Powered by four motors, this fully-automated, pre-programmed machine only needs you to push a “start” button.  The mechanism seeks out a burned out light bulb, unscrews it and places it in an appropriate reception bin.  Next, it finds a replacment bulb in a rack of spare bulbs, unscrews it, moves to the original location of the burned-out bulb, and proceeds to screw the new bulb into the electrical socket.
    This robot answers the age-old question, “How many degrees of freedom does it take to change a light bulb?”