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ROCKET CONSTRUCTION
This rocket was built in September 1993 and was my first large semi scale rocket. It gave me an insight into high power before I started using Aerotech motors and was designed to fly on 7xD12 Estes motors. That is equivalent to around a 'G' Aerotech motor.
1) BODY TUBE
The body tube was made from 4inch diameter cardboard tubing used to store drawings and weighs in at around 1lb.
2) NOSE CONE
The nose cone was made up from different sections of plastic bottles that matched well into a cone shape. Not too bad for a first attempt but future designs would be better.
3) MOTOR MOUNT
The motor mount was made from two discs of thick (3 layer) corrugated cardboard. 6 motors are arranged in a radial pattern with one other in the centre. The motor mount tubes between these where rolled out of thin card and formed to the correct shape by rolling around a spent motor casing. The whole assembly was coated with high temperature silver paint. The motor mount tube retainers were made from metal Arco clips used for filing papers. These can be bent many times before breaking and were readily available. The motors were also tapped in with masking tape for good measure.
4) FINS
The fins are balsa and shaped to scale.
5) RECOVERY SYSTEM
The rocket was retrieved using a parachute made from thick yellow waste bin liner. Cheap but effective!
The shock cord was 1/2inch flat elastic from the hardware store. This was mounted onto the side of the tube as in the smaller Estes models, as I had no other design to base this on. This design proved to be no good for this size model during a later flight as the mounting is not substantial enough.
6) FLIGHT
From experience with some previous rockets I had come to the conclusion that a launch 'rod' was not a very stable design to launch a rocket. I decided to use a launch 'rail' instead. This would allow for a heavier rocket and give good guidance off the 'rail'. This is simply made from curtain rail. Different designs are available and in different widths. This is then fixed to a long straight piece of wood around 2x1.5inch is OK.
First launch of this rocket was on the Copland Model site in Cumbria. This site is ideal for launching rockets with plenty of open space well away from houses and roads. We arrived late afternoon to a stiff wind. I had never launch in wind before and did not know what to expect. The rocket was loaded for launch with 7xD12 motors and all Estes ignites wired in parallel. Ignition was done just by touching bare wire ends into the car battery. Steve and Duncan watched with Video in had from a safe distance. The countdown given and the wires touched. A large flame appeared and the rocket rose up and then headed down wind! The chute opened and it was recovered OK. Altitude was less that 1000feet but all systems worked. But I would be careful about launching into wind again.
The rocket flew a few times after this at Broken Bank flying site (Home of the Heswall Model Flying Club) on the Dee Estuary on the Wirral. The final and fatal 'Flight of the Phoenix' was at this site in 1996. This flight was onlooked by members of the Heswall Model Flying Club. The weather was fine and sunny and the rocket was loaded with 7xD12-5 motors. The rocket was pointed away from the spectators and the countdown given. The rocket lifted off on a large plume of smoke and flame to a decent altitude. It then turned over and headed for earth. I apparently was heard shouting at it saying "OPEN........OPEN.......", but all the shouting was a waste of time. The rocket picked up speed and 'whistled' into the ground followed by a dull thud! The rocket was terminated and never flew again. It appeared as if the nosecone had somehow jamed onto the body causing the rockets sudden retierment. Lessons learnt are to ensure the recovery system is packed correctly!
Above image shows the rocket lifting off on its final flight with 7xD12 power.
What remains of the rocket after it hit!! The parachutes can be seen trapped in the
top section with the engine cell buried deep inside the rocket.
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