An Introduction to Water Rockets

At first, I just built rockets that had no recovery system at all, this makes things simple if the rocket survives the crash.

Successful parachute deployment, not easy without a system to push nose off.

Blast Off!!!

Rocket came apart on high-speed launch.

The Launch

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.

For water rockets you need a good quality pump, the pump on the left was a cheap one and did not hold up. The pump on the right has gauge which is necessary.

In this picture you can see the jaws clamping around the bottle.

Some method for carrying and pouring water is needed at the launch site.

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 above 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.

Fishing swivel helped with the twisted lines.

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.

Fins cut from the lids of cottage cheese containers.

Fins cut from foam.

Foam nose bumper fastened with rubber bands.

The next few pictures are 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 taped the bottle when painting to create a water level indicator.

Depressing the air chamber.

The air flap hold vacuum in air chamber, flap rips off at launch, releasing the vacuum which pushes the nose off.

Nose pushed off.

First rocket I built with a timer system. Spring mechanism pulls a pin which releases a spring that pushes nose off. It is fun to engineer new solutions and to refine the solutions.

Timer is in the bottom-right, servo arm is attached to the knob on timer, string attached to servo arm pulls out the pin.

When pin is pulled out, a compressed spring pushes hinge up and the rod that pushes the nose off.

Long rod pushes the nose off, I will refine this in future versions.

Braided wire holds the timer until rocket launches which pulls the wire out releasing the timer.

Parachute deployed successfully!!

Touchdown!