Vertical windmill 1. Divide the cans vertically into eight equal parts, cut the cans into strips along the line with a sharp knife, and cut a small mouth at the upper and lower ends of the incision. Don't connect the small cross-cutting holes together and stagger them, so as not to break them when screwing the blade. 2. Twist each of the eight cutting belts in one direction. The angles should be consistent, then a snap button is embedded in the triangular opening at the top of the can as a support bearing, and a small hole of 1.5mm is drilled in the center of the bottom of the can. 3. Sharpen the upper end of bicycle spokes, insert a wooden board as a bracket at the lower end, and put the finished windmill model on the bracket. At this time, as long as there is a breeze blowing, the windmill can rotate quickly. 2. For the anemometer model, the left and right halves of the can are cut off with scissors, and a hole of 1.5mm is horizontally drilled in the middle of the can as shown in the figure, and a snap button is embedded in the hole as a support bearing. At this time, the model of the anemometer is ready, and it can be rotated according to the speed of wind speed on the bracket. Third, the air convection demonstration took off half a can, cut it into 16 leaves about 2 cm deep along the incision, and broke it into a straw hat. Then twist each blade by an angle in one direction. Drill a 2-3 mm hole in the center of the bottom, and embed a snap button in the hole as a support bearing. Put the presenter on the shelf and light the candle, which will keep turning. A lamp made of canned food. 1. Manufacturing materials: 2 empty cans, 1 small switch, 1 2.5V electric beads, wires, Black & Decker glue or 502 glue, solder and batteries. Second, the production method of 1, cut off two cans respectively, and leave the edge of 10 mm around one of the bases. 2. Open a round hole with a diameter of 5 mm in the center of a pedestal without leftover materials, then open a 4×7 (mm) switch mounting hole at a distance of 10 mm, and then cut out four equidistant pins around the pedestal. Then, the periphery of another working seat with external space is cut into three-point wavy lamp feet, and then the protruding parts of the base are staggered on another base according to the integrity of the pins and tongues, and four pin holes are filed with a file. 3. Cut and flatten the can. Cut a piece of 15× 100 (mm) and bend it into a lamp holder. The joint of the lamp holder is fixed with Black & Decker glue, and round holes with diameters of 8 mm and 5 mm are drilled above and below the lamp holder respectively. 4. Cut a 55×20 (mm) aluminum can and bend it into a hollow cylinder with a diameter of 5 mm. 5. Take the aluminum sheet of the can and cut it into two lampshade fixing frames. After bending, use Black & Decker glue on the inside of the lamp holder. 6. Cut four knives on the reverse side of the lower insertion part of the hollow cylinder, then analyze it 90 degrees outward and stick it firmly. The upper part of the cylinder is wrapped with a circle of transparent adhesive paper, covered with a lamp cap, and reinforced with glue around it. Small electric beads welded with wires are screwed into the round hole above the lamp holder, and the wires pass through the hollow cylinder and out of the upper base. Stick the small switch firmly in the square hole of the upper base, then tie the No.7 battery and put it in the lower base, then connect the whole circuit with wires, and finally insert the pin tongue of the upper base into the pin hole of the lower base, bend the pin tongue and connect the upper and lower bases. In this way, the desk lamp is finished.
Find a concave reflective bowl on a big flashlight, and cut it into a cylinder about 4 cm long with rigid foam plastic or wood, just enough in diameter to fit into the round hole of the reflective bowl. Drill a fine hole horizontally at one end of the cylinder, insert an iron wire with a diameter equivalent to the aperture, and then bend the two ends of the iron wire exposed outside the cylinder at 90 degrees, leaving 5 cm each. Insert the cylinder into the round hole of the reflective bowl, and then insert both ends of the iron wire on the foam plastic or wooden bottom plate. Sharpen both ends of a thin bamboo stick, insert one end into the cylinder in the center of the reflective bowl, and insert a small piece of potato at the other end. Put the device in the sun, let the reflective bowl face the sun, and then, patiently adjust the length of the bamboo stick so that the inserted potatoes are just in the focus of light. Before long, the potatoes will be cooked by the sun and smell delicious.