Instructions on building a solar-powered hotdog cooker.
What to do ?Select a long narrow box; the longer the box the more heat collection is possible. Choose a focal length between 5″ and 10″ and design a parabolic curve as seen in the picture. One template could be used for all the cookers. Trace the curve on the open end of the box so that it is centered and straight.Cut out the curve with a utility knife. Stress the importance of being exact. Measure and cut a piece of posterboard that will fix flush against the opening to the box. Attach this with tape beginning at the center and working toward to edges.
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