Water rockets are used in school/scouting/4-H presentations to help students understand the principles of aeronautics. This project is geared towards middle school aged students. However, the project has been given to high school students and they enjoy it as well. Everyone is happy to get out of class and play with water.
Five rocket stations should cover a typical class (divide the kids equally). The stations are pretty easy to build and relatively safe since the PVC reducer locks the rocket in the vertical position. Fins and nose cones were not added since this setup needs to be durable to cover multiple classes per year.
Note that the rocket release is not controlled. The rocket launches when the pressure inside the bottle forces the stopper from the nozzle. For this reason, the kids should stand back when applying pressure to the bottle. Depending on the stopper seal, rockets can fly as high as 50 feet.
This project was built for an intro to engineering program called DiscoverE. For more information on the program, see this link: http://www.discovere.org/
Step 1: Materials and Tools
Step 2: Cut Baseplate
Cut sheet of wood 16" x 16". Optional - cut 3 3/8" diameter hole in center of board.
Step 3: Add baseplate blocks
Add baseplate blocks to the four corners of baseplate.
Step 4: PVC Pipe
Cut pipe 3 3/8" diameter PVC pipe to 9". Cut slot as shown
Step 5: Attach pipe to base
Glue pipe to center of board. If hole was placed in board, slide pipe through hole and glue both sides. This will give a stronger setup.
Step 6: Add Reducing Fitting
Place reducing ring on top of PVC pipe. This completes the rocket launcher setup.
Step 7: Extend hose
Extend the length of bicycle pump hose by cutting it in half and adding in the clear tubing. Use hose clamps to seal the ends.
Step 8: Stopper (cork)
Drill a small hole through the rubber stopper - just enough to fit the needle through the hole (needs to be a tight fit).
Feed the needle through the stopper so the threaded side is on the wide end of the stopper. Clamp the stopper to the pump. If needed, add tape for additional support.
This completes the pump assembly.
Step 9: Add water
Add water to bottle - question the kids on how much water should be added.
Step 10: Place reducing fitting on bottle
Step 11: Press stopper into bottle
Step 12: Place bottle/reducer/stopper assy onto pipe
Step 13: Ready to launch
Step 14: Shoot the rocket
Move pump away from rocket and start pumping. Rocket will release when the pressure overcomes the friction of the stopper.
See embedded video for actual launch!