In this video, set to dramatic music, you can see us creating a prototype mechanized air duct. We took a piece of commercial duct; added a paint-can top, and attached foam to widen its circumference and a metal rod to pivot it inside the air duct. Next, we cut a semi-circle of foam (3/4 inch thick), cut that semi-circle into two quarter circle pieces, and cut a notch in the curved edge of each. This notch will act as a guide for a rubber band. These two pieces are attached on either side of the metal/foam piece, perpendicular to it. A small DC motor is connected to the top of the air duct, and a slat cut to allow a rubber band, connected to each lower end of the quarter circles, to pass through and over the motor shaft. For now, dabs of hot glue stop the movement at the correct places to allow for fully open and fully closed positions. Simply reverse the current applied to the motor to reverse the movement of the duct door. In the next version of this prototype, we will include a belt drive instead of a rubber band; other improvements to follow, as well. The boring beginning to this video is due to Bill Goodrich.
