How to Make a Solar Lens

Find your fresnel lens. Choose a large, plastic, flexible lens. The best types of lenses for this project are the fresnels found on projection TVs. These can be purchased online or easily removed from a broken projection TV by opening the front of the TV and unscrewing the lens from the housing. If using a used lens, clean it carefully with non-streak cleaner, and check for any discoloration or flaws that may compromise the quality of your lens.

Construct a frame for your lens out of the 2x4 two to three inches wide, leaving room for a half inch of the lens on all sides. Secure the frame with screws and epoxy, and let the epoxy set for two to three hours. Carefully drill holes around the edge of your lens, going slowly. Do not force the bit through, as it may crack the lens. Screw the lens to the frame.

Construct a standing frame for your lens. Cut a length of 2x4 slightly longer than your lens, and attach two-foot lengths of wood to either end. Attach two four-foot boards to the crossbar, pointing straight up, to support your lens. Drill one-inch holes at the top of each support, taking care that the holes are even with each other. Place the framed lens next to each support, and drill a one-inch hole in either side of the frame. Bolt the lens to the support beams with one-inch bolts and washers.

Attach the castors to the bottom of your frame at either end of both "feet." Push the frame around to make sure that it rolls smoothly and easily.