Practice of small-scale production of scientific and technological labor in grade four. Please. . . Something simple.

I'll give you two plans. Choose for yourself. An exquisite woodwork flower stand.

Material: Cedar wood can be used if possible, because its natural fragrance can drive away insects without producing fungi. Of course, you can also choose other wood. The key is to be durable and withstand wind and rain. These woods can be bought in large timber markets in the city.

Tools: Common woodworking tools, excellent wood glue, and several long screws.

In order to make you more aware of the production process, I will first provide you with a basic production idea: on a piece of wood similar to a girder, fix a brace every 40 cm, and use a *** 10 to run through the girder like a rib; The "rib" is equipped with seven horizontal bars, which are parallel to the beam.

In order to make the stay stick to the main beam firmly, we use the semi-enclosed joint, dig a 3 cm deep V-shaped groove on the main beam with a saw, and smooth its surface with a plane or chisel.

In order to match the bracket with the V-shaped groove, the width can be drawn on the base first.

When installing, apply a thin layer of woodworking glue in the groove to install the bracket. Practice of two kinds of small launch vehicles.

0 0 material: 1 plastic straw, cardboard, plasticine, 1 small spring, 1 steel can, bicycle steel wire, a piece of 100×50(mm) board, and two small nails.

Production method:

0 1. Cut a 20× 100(mm) steel plate from the can, and drill Ф 3 mm holes at both ends according to the figure.

0 2. Insert the steel wire of the door crane on the board, insert the thin steel sheet and spring according to Figure 2, and then fix one end of the steel sheet on the board with a nail to make the transmitter.

0.3. Cut out four wings from cardboard and fix them at the lower end of the plastic straw so that the bottom forms a cross. Finally, the plasticine is inserted at the top of the plastic straw to make a rocket.

0 play: put the rocket on the steel wire of the launcher, press the spring steel under the skin with your hand, and then let it go, and the small rocket will automatically pop up. Pay attention to safety and operate under the supervision of parents and children.

Paper flowers for forecasting the weather

Materials: pink colored paper, disposable paper cups, straws, decorations, salt water and newspapers.

Production process: cut art paper into petals, coat it with salt water, dry it, stick it on one end of a straw to make flowers, put it in the center of a paper cup by hand, and stuff newspapers on both sides to make soil (press the newspaper with water to level it) and decorate it.

"The petals are very thick and will soon be wet or rainy. At dawn, it is sunny.