How do pupils make flying rockets? (fire breathing)

I have an easy-to-implement design, which was made in primary school, but the homemade rocket is not safe, and it is forbidden to be used under 10:

1。 Fuel: knock off the match carefully and crush it. Then bake it on the candle with a spoon, scrape off the black layer and collect it. You can get some nitro fertilizer, melt it in water, boil it and filter it with gauze, then continue to cook until a small amount of crystals appear in the water, then stop heating, let the water evaporate, and carefully scrape off the crystals with nonmetal. These three samples were carefully mixed together according to the preparation sequence of 1: 2: 3, and became rocket fuel.

2。 Engine: You can use paper roll instead of thick kraft paper. The wall thickness of a paper roll with an inner diameter of less than 5 mm should not be less than 2 mm. It is recommended to use a metal tube with a diameter of more than 5 mm. One end of the rolled tube or metal tube should be sealed with gypsum or clay. Carefully inject the prepared fuel, insert a long lead wire with two legs, and then plug it with paper balls, not too tight. This is the engine.

3。 Rocket shells: it depends on personal preferences. Design it yourself. You can add a parachute. That's when I started flying directly with a conical hood.

4。 Launch: It is suggested to make a special launcher, and try to make it with drums that are not easy to burn and will not deform when heated. Leave the launcher immediately after igniting the lead and evacuate to a distance of 5 meters, and then approach the launcher after launching or 10 minutes.

note:

1, once again, this experiment is very dangerous, and people under 10 are forbidden.

2, paper rocket engine can only be used once, it is strictly prohibited to use more than 2 times.

It is recommended to bring a small fire extinguisher. When the fuse is lit and the rocket has not been launched for more than 10 minutes, it will be sprayed with a fire extinguisher to reduce the danger and scrap the rocket.