Water Rockets (What I Have Learned so Far) by Bill Kuhl
http://www.scienceguy.org
News Flash! Power Point Version of this article Wins Presentation of the Week @ SlideWorld.com
The idea to try water rockets came to me after helping with a parks and recreation summer camp that was entitled,
"Model Airplanes and Rockets". For at least one summer there were no rockets but we built kites instead of rockets,
and of course there was little wind. I had built solid fuel rockets as a kid but I knew that would be rather expensive for
a large group, so I thought the water rocket idea would be cheap once I purchased a launcher. Some people build
their own launchers, but I purchased the better launcher from Pitsco. At first, I just built rockets that had no recovery
system at all, this makes things simple if the rocket survives the crash.
Below are pictures from a park and recreation group, they built the rockets mainly from construction paper which
does not hold up to a high-speed launch, but the kids sure had fun!
For water rockets you need a good quality pump, the pump on the left in the below left picture was a cheap one
and did not hold up. The middle picture shows how the Pitsco AquaPort launcher grips the bottle. Another requirement
will be a method for bringing water to the launch site and pouring it into the rocket.
The launch of a water rocket is really fun to watch, within the first few feet all the water has been emptied from the
bottle and the rocket can be going over 100 m.p.h.! Safe practices are a must.
Parachute recovery is really cool, but it is difficult to get reliable deployment every time, I tried a few methods with
varying success.
Below is what happens when the parachute does not deploy. Sometimes you can fix the rocket but sometimes it is
best to try a new rocket and another approach.
What are the problems and how can I fix it, that is what I thought about all the time. In the picture in the below left, the
fin material was not stiff enough for the size of the rocket and was fluttering in flight. Altitude is greatly reduced when
that happens. Another problem I had was with the parachute lines twisting, using a fishing swivel helped this greatly.
I tried many materials for the rocket fins; foam, cardboard from a milk carton, and plastic from cottage cheese lids. The
material needs to be rigid enough and waterproof.
Below are pictures of a Pitsco Saber rocket I built from a kit. An air chamber that was held squeezed down by vacuum
and released slowly when the flap on the rocket came off was used for parachute deployment. This worked well for
several launches and then it failed for two launches. It was a simple method for parachute deployment if only it was
always reliable.
I purchased a rocket from AntiGravityResearch Company. Their rockets use a small hole for a nozzle and all the
parts are held on by rubberbands. A small tube is pushed in the nozzle hole and when you stop pumping, the rocket
launches. The launch speed is slower with this method.
The pictures below are of a rocket I designed using a wind-up timer to push the nose of the rocket off. This can get
rather complicated but it seems to be the most popular method with the more advanced rocketeers. I have only
launched this rocket twice; it worked perfect the first launch and the nose came off too early on the second launch.
Currently I am working on an improved version of this rocket.
Water rockets are really fun and a great way to learn engineering skills. Rockets normally are built from inexpensive
materials and experimenting with new materials is half the fun. I have a video on YouTube which explains what I
have learned in more detail.
An Introduction to Water Rockets I - Video on YouTube I created about water rocket experience.
Water Rocket II- my latest water rocket video, experiments in the second year of water rockets .
An Introduction to Water Rockets I (Power Point) - Like the article above with additional pictures.
An Introduction to Water Rockets I (PDF file)
Water Rocket Links from Izzi's Home Page - Water rockets are used as part of a university computer
programming course.
Water Rocket Resources from National Physical Laboratory Water Rocket Challenge
Water Rocket Forum - an excellent resource for water rocket questions.
Water Rocket @ Leeds - http://www.ast.leeds.ac.uk/~knapp/rockets/Rocket_Home.html another good
UK water rocket resource.
Texas Timers - my source for the timer devices used in parachute deployment, select Plastic Clocks.
Consider These Fun / Educational Activities Also:
Model Airplanes