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.
6, homemade colored candles
Materials: colored crayons, wax
Production method:
1. Find an abandoned canned beverage barrel (for example, 1.25 liter coke bottle), cut off the lid and cut the wax into the barrel.
2. Put the bucket in hot water, stir the wax inside and let it melt completely. It is best to use boiled water. But ask your parents for help, or do this step under their supervision.
3. Pour the molten liquid into a beautiful container (for example, put a heart-shaped chocolate box). Don't pour too much. As for the reason, look down. Of course, you have to put the thread as a candle core in the container first.
4. The original idea of wax cooling, A pours the melted colored crayons in according to the surface painting method (colored crayons come in handy at this time). In this way, different colors of wax are added layer by layer, and beautiful candles are made.
7. Self-made wall-mounted flower basket
Materials and tools: two sprite bottles, glue, meat cleaver, scissors.
Production method:
1. Remove the green bottom cover of Sprite bottle, cut it into lotus shape, turn it over and stick it on the bottle body to form the base.
2. Cut a 2 cm wide green ring from the green bottom sleeve and put it on the bottle.
3. Remove the bottleneck, and cut a wide band of 13cm long and 8cm wide and several narrow bands of 3cm wide on the bottle body.
4. Carve a pattern on a 3 cm narrow strip with a meat cleaver? As shown in figure 3, then fold these narrow strips outward and insert the green ring from bottom to top.
5. Take another beverage bottle, use the bottle body and cut out 6 leaves with scissors, the length is 17 cm.
6. Nail the flower basket on the wall, insert leaves and flowers, and the wall-hung flower basket will be ready.
8, homemade cockroach catching box
Take a piece of 220× 150(mm) cardboard.
The most important part of the capture box is the capture surface. Take a piece of plastic film, cut it into the same size as the bottom of the box, coat it with adhesive and spread it on the bottom of the box. Whether you can catch cockroaches depends on the adhesive. The adhesive has two functions: one is to introduce the cockroach into the box, and the other is to firmly stick the cockroach to the catching surface. Preparation of attractant: Mix 40% meat powder, 50% flour and 10% bean cake, with a total amount of about 20g, and mix well for later use. The adhesive is prepared by mixing 20g of rosin and10g of vegetable oil, heating to gel, and uniformly mixing attractant and adhesive.
Spread the prepared paste evenly on the grasping surface lined with plastic film, then fold it inward according to the original dotted line, and finally insert the tongue piece B into the notch A..
Because the mixture of rosin and vegetable oil is not dry, the viscosity of bait can be as long as one week. Put the trap box in the place where cockroaches haunt. Because the box is dark and has the bait that cockroaches like, cockroaches will climb into the box to fight for the bait and get stuck on it. When it is full, the carton can be crushed and discarded, and the plastic film can be removed and replaced with plastic film coated with bait, so that the box can be reused.
If the size of the catching box is enlarged and the composition of the adhesive is slightly adjusted, the paper mousetrap can be made by thickening the coating.
A clean eraser with a brush
If you make a mistake, use an eraser. After wiping, there will always be a lot of debris left on the paper. It is unsanitary and troublesome to pat by hand or blow by mouth. It won't be so troublesome to make a clean eraser.
Material: large rubber, waste brush.
Tools: scissors, glue.
Production method:
1. Dig a small and shallow round hole at one end of the rubber. 2. Remove the tip of the waste brush, clean it and dry it.
3. Cut off the tip of the brush head to make it a small brush.
4. Insert the brush head into the small round hole of rubber and stick it firmly with glue.
Ok, the clean eraser is ready. Whenever you finish wiping the eraser, you can gently "sweep" the crumbs off the paper with a brush and then pour them into the wastebasket.
This is very simple, the key is thinking. I also made a small production in junior high school and won the third prize. The key to this kind of production is to come up with good ideas, and the production is not difficult. Let me recommend my little production to you.
I made a small electronic balance model. Note that this is a model, which can only weigh very light objects, such as two small pieces of paper. The materials needed for production are: a wooden board (preferably thinner, not too big), a washer, a paper clip, an awl, an electric soldering iron, several wires, two light-emitting diodes and a battery. These materials are easy to find. If there is no led, you can go to the electronic market to buy it. They are very cheap.
The manufacturing process is as follows: drill a small hole in the middle of the board with an awl, bend a paper clip into a hook shape and fix it on the board through the small hole perpendicular to the board, as long as the washer can be hung on the hook. Then take two paper clips and straighten them in half, leaving only one corner. In fact, the straight part is the arm of the balance, and the remaining curved part is the tray. Another paper clip does the same thing. Then use the middle washer to weld the two paper clips together, and the paper clips should be in a straight line. Then hang the washer on the hook, adjust the distance between the hook and the board, about 3 mm, then fix two paper clips under the two trays, and prepare led as the indicator light next to the paper clips. A circuit is arranged under the board, and the balance is equivalent to a single-pole double-throw switch. This circuit is equivalent to two loops, using a power supply and two light emitting diodes. As long as the left side sinks, the tray on the left side will be connected with the pin below him, so that the circuit will be connected and the diode will emit light; If the two sides are equal in weight, the circuit is blocked and both diodes are not lit.