Thursday, 31 July 2008

Booster Rocket Project

We are starting a new project. We are going to make a water rocket with boosters. The boosters will be mounted on the side, a bit like Aircommand. The booster will be three 1 litre bottles that are held to the main stage with some pins. The main stage will be 6 litres and will weight about 430grams. The main stage will use a 5mm nozzle for maximum thrust time and the booster will use an 11mm nozzle for maximum thrust. The booster will also have a 23cm long launch tube for an extra boost and maybe another 50ft higher. The simulator says that it will go 437ft but i will be happy with just 400ft. If you want to see how this will work click here. I wont be able to make anything else for the rocket because it is still in the tree but i can start building the launcher.

New Aerodynamic Rocket

Today we started to think about the aerodynamics of a rocket and we have made a prototype to test how important the aerodynamics really are. This rocket is an aerofoil shape, its tapered at the back for drag reduction.
The picture shows the air flow as it passes over the rocket.
The capacity of the rocket is only 3 litres and it will use an 800mm long launch tube with a 10mm nozzle. The rocket is also 80mm diameter so it is thinner than the 100mm bottles that we normaly use.

Tree problem over

Today we spent all day preparing the long thin pole that was going to pull the rocket down. The pole had to be 25ft (8.8m) long because I only had a 5m long ladder. The pole had to be very strong and very light for me to hold whilst I (Tom) was up the ladder. I had a couple of goes to get it down but all i could do is poke it. Then Fred made a hook to go on the end of the pole to pull it down. Fred quickly made a hook out of a coat hanger we and tried again. This time we were successful, we pulled down the rocket and checked that the altimeter was alright. Everything was alright.

Monday, 28 July 2008

Problem with the tree

On Monday we had a big problem with one of our 6 litre rockets, it was being pressurised when it launch without knowing, so we only caught the rocket descending by parachute on the video. It flew straight into a large tree and is about 45ft from the ground. The problem is, it contains the parachute deployment system and the altimiter so we wont be able to beat the record until it comes down.

Sunday, 27 July 2008

New Logo

This logo was created by Daniel.

If you didn't know what TDF stands for, it means:

Tom (T)

Daniel (D)

Fred (F)

These are the TDF members and are the creaters of all the rockets.

Saturday, 26 July 2008

4Litre water rocket record

Today we set a new TDF water rocket record. Our old record was only 238ft but our new record is 266ft. Our next aim is to reach 275ft. After the launch the wind started to pick up so we didn't launch again that evening but we did adjust the rocket a little. We maneged to reduce the weight by about 15grams so we could beat the record tomorrow. To see this rocket fly click here

It looks like an excellent flight but when we checked the altimeter data it wasn't a smooth line to apogee, the suddenly stopped and started to descend. This could only mean that the parachute deployed too early, if the timer was a bit longer then we could have reached 275ft.

Stability Problem

We had a problem with the fins, it kept on spin violently out of control and the nosecone was wobbly. We could only reach 226ft, so we went back to workshop to rebuild the fins and nosecone. The video shows that it wobbles quite a lot so the rocket wasn't as efficient as it should have been. To see the rocket fly click here