Step 1Lets get Started
A water rocket is propelled by pressurised air forcing water down though a nozzle. This creates thrust.
If you took a standard two litre fizzy soft drink bottle and pressurised it to120 psi the rocket would reach about 100 or so feet.
But then if you took 2, two litres bottles and pressurised it to 120 psi again the rocket would go about 150 feet or so because the rocket has more air in it therefore creating more thrust. The rocket will only go 50 feet more because of the added mass. You can stop this by making a two stage rocket. A two stage rocket will work better because it would not have to carry the full payload on all of its flight.
Step 2How to build a fins and nose cones
In the next few steps you will be shown how to build the basic needs of a bottle rocket.
This step is to get to grips on what a rocket needs.
Step 3Step 2: Nose cone
Cut a ping pong ball in half with a craft knife,
Then glue half of the ping pong ball into the top of the 1.25 litre bottle 'top'.
Use a Plastic adhesive glue, Or if apperance doesn't matter you could just tape it on!
Step 4Step 3: Nosecone
Glue or tape the nose cone to the top of the rocket.
Adding wieght to the nose cone may help, It will move the centre of gravity higher, thus being more stable.
This stage is still the basics of how to make a water rocket but may help in later projects.
Print off the fin template from the link below... Or design your own..
Then glue the fin template on to cardboard, then cut it out or use it as a template for corregated plastic.