Furze Platt Greenpower Racing

Using the experience gained by the pupils with the Sprocket Rocket made several decisions easier. 

The ‘Sprocket Rocket’ was built out of a lightweight frame of  plywood stitched and glued together which had proved to be simple to build and very strong having coped with many races and knocks whilst drivers were learning. It was decided the new car should also be built using the same method  and the pupils would be using a tried and tested method of construction.  

The wheels of the ‘Sprocket Rocket’ had been reliable and fast so these were also adopted for the new car.   

The batteries of the ‘Sprocket Rocket’ were considered too small for a fast car that was going to weigh more due to the body so the larger ones were chosen. 

As the weight was going to be increased and the pupils were growing all-wheel braking was chosen using brakes that we had used on many of the Kingcycle projects. 

Gears were also considered a requirement due to the weight and the expected top speed.  This decision was not taken lightly as the ‘Rocket’ had been fitted with gears initially but they had proved very  troublesome.  So again using this experience it was decided that a lay shaft was needed to gear down the motor before the 7 speed block.  

The ‘Rocket’s’ motor is air cooled which is the simplest system but unfortunately of no use inside a body, so a total loss water cooling system was adopted for the ‘Tortoise’.  The drawback with this is having to fill tanks (coke bottles) at pit stops and extra weight, due to the copper coils and the water. This probably added about 7 kilos to the weight.

The steering on the ‘Sprocket Rocket’ tended to pull slightly to the left or right under breaking which was identified to the steering geometry being slightly out so this flaw was worked on to avoid this problem in the ‘Tortoise’. 

Slack in steering linkages on Kingcycle’s traveling at high speed had been an issue in the past so again all the linkages were simple and short to avoid this problem.

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Last modified: 08/06/09