Working on this vehicle has been a great experience. We test drove it quite a few times and each test made us know much more interesting things about it. Initially, we couldn’t reach our estimated power and distance but some changes to the design and distribution of apparatus made it efficient. Some of the major problems we faced are mentioned in brief.
One major change which turned the tide was the introduction of chain drive system replacing the belt driven system. The rubber belt was used to connect the motor shaft and the rear axle with the help of a pulley. As the number of tests increased, the belt began to expand due to the heat produced due to the friction between the motor shaft and the belt. This led to increased power consumption by motor which led to fast discharge of batteries. Also the belt had to be tightened by changing the position of motor which is a tedious job. The chain drive system answered all the queries of the previous system by decreasing friction, no requirement to displace motor, decreasing discharge and no jerk movements or slipping of the belt due to initial start-up.
The selection of a reliable braking system is a very important part of achieving proper vehicle control. We started with disc brakes for both front and rear axles. The front axle brakes are making the design of the steering system complex and it had to be replaced. So, they were changed to drum brakes which are placed inside the tire rim by giving us proper space for the steering. We also replaced the rear brakes with drum brakes but due to lack of professional knowledge on this kind of complex braking, we could not achieve 100 % braking. This had a drastic effect on the morale of the group as it resulted in an accident breaking the entire rear axle into half. Finally, we settled the problem by the use of mechanical disc brakes to rear axle which are mounted on the rear axle beside the pulley. It had a simple operation and selection of proper disc brake helped us by achieving efficient braking.
Some practical changes include placing the thermocol sheets under solar panels and metal apparatus to damp the sound created during the vehicle run. Using a better insulated wiring in place of regular wires to withstand the heat produced by the high current flow. Distributing the weight of the apparatus innovatively by not clustering all the parts of a specific apparatus at a single place.