2 wing making. Cut the X-ray film into 28 right-angled trapezoidal blocks with the same size with scissors. The trapezoid is 12cm long and 6cm high, and the included angle between the inclined waist and the long bottom is about 45 degrees. In addition, four trapezoids with the same specifications but 8cm high are cut out, the short bottoms are connected and the two sides overlap (used as wing surfaces). Use double-sided tape to closely stick seven small trapeziums into a thick trapezium to make it flat, and then tightly wrap and stick it with a large double-sided trapezium. In order to make the thick surface of the wing flat, it can be flattened and straightened with scissors or a knife, and then the thick surface of the wing can be sealed with insulating glue. Finally, the parts that grow on both sides of the wings are folded 90 degrees outward. In this way, the remaining X-rays are made into three wings according to the above method.
3 fuselage production. Take a Jianlibao bottle (the curvature of the bottle head is too natural, which is conducive to reducing the air resistance as a rocket head), cut it horizontally from the lower end 1 1cm, stick the part with the bottle mouth to the bottom of another bottle with insulating glue, and wrap the interface firmly with insulating glue.
4 air plug making. Take a No.4 soft rubber plug, open a flat hole slightly smaller than the valve core sleeve in the middle of the bottom of the rubber plug with a hole-opening tool, and then cut off the fine end by about 0.6cm； with a knife; Put a big "ring" on the valve core (sold in hardware stores), install the valve core upward from the thin end of the soft rubber plug, put on the same "ring", screw on the screw and tighten it slightly. Finally, grind the gas plug into a cylindrical shape with a grindstone until it can completely enter the coke bottle mouth or be slightly tight, and then the valve core can be used.
5 gun head production. Take a No.3 soft rubber stopper and sharpen it with a knife.
6 Assemble the wing. Take a Jianlibao bottle, cut a cylinder slightly longer than the wings, and then closely glue the four wings into four parts with transparent glue and insulating glue. Finally, put the cylinder with wings attached to it at the bottom of the water rocket so that it is flush with the bottle mouth (this is not necessarily the best position, but it can be adjusted up and down in flight practice to find it), and wrap it with insulating glue to make it stick firmly.
7 others. In order to increase the contact surface between the air plug and the bottle mouth and increase the air pressure in the bottle, the big end of the air plug can be thinned with a knife to make it flat and rough. Because the fuselage has the rocket head part, so the rocket head part is relatively light and unbalanced, so it can be properly stuffed with paper to achieve balance. In order to reduce the air resistance as much as possible, the gun head made of soft rubber plug will be glued to the bottle mouth of the rocket head with 502.
According to the above method, a simple water rocket was made. According to the water rocket developed by us, through practical improvement, the horizontal flight can reach about160m, and the vertical flight can reach 40 ~ 50m.
Water rocket launching method:
1 water regulation. There is a certain proportion between the water consumption of water rockets and the air space of rockets, neither more nor less. The optimum water consumption is about1/4 ~ 2/5 of the rocket air space (the space of 2.5 liters is about 600 ml, which can be determined by multiple tests).
2 launch angle. For horizontal flight, the optimal launching angle is between 50 and 55 degrees due to air resistance, which may be different for different water rockets and can be determined by controlling variables. The best angle of our water rocket is about 53 degrees. Vertical flight is 90 degrees.
3 air plug use. The use principle of air plug is to adjust the tightness of air plug by compressing the volume expansion of soft rubber plug. The greater the compression, the greater the volume expansion, the tighter the air plug, and the greater the air pressure that washes the air plug, that is, the greater the power that the rocket gets. The specific use method is: firstly, remove the valve core of the valve plug, insert the valve plug into the bottle mouth of the rocket as it is, then tighten the screw of the valve plug with a sleeve (a special tool for screwing screws, which is sold in hardware stores), and finally install the valve core to be used for inflation. (Note: The tightness can be adjusted as required. )
4 launch stability control. Only horizontal launch is discussed. Need to make a launch pad, the launch pad should have a navigation track, the navigation track should not be too long or too short, generally 60cm long (three teaching triangles and two broomsticks can be spliced together, in order to reduce the friction of the broomsticks on the water rocket when they are used as navigation tracks, the broomsticks or the models shown in the legend can be pasted with transparent glue). When there is no wind, the target is launching at the best launching angle (the angle between the launching track and the ground). In windy weather, the direction of the target should be properly adjusted according to the wind force and direction to maintain the best launching angle.
5 precautions. When launching, make sure that the rocket is straight and consistent with the orbit. If it deviates from 1~2 degrees, it will affect the flight stability and fly in the shape of "8" When pumping air, it should be as smooth as possible, and the pumping frequency should be fast, not too slow. In order to tighten the air plug as much as possible, it can be adjusted by tightening the screw of the air plug. The tighter the air plug, the greater the air pressure in the bottle, and the greater the power of the rocket.