Compact Electric Personal Transport

The goal of this project was to design a compact and powerful personal transport vehicle around the high performance electric power systems associated with large radio controlled aircraft. The relatively powerful and lightweight components associated with these models are the perfect candidate for this application. The selected electric motor for instance is rated at 3kW of continuous power with a mass of just 384 grams. There were engineering challenges that arose from using these types of components for a vehicle application. At its designed operating voltage the motor will be spinning at around 25,000 rpm. This will require a novel reduction drive to get useful torque to the rear wheel and a reasonable top speed. Different mechanisms for transferring rotational motion including roller chains, gears, and timing belts were considered before deciding on the 2 stage belt system. The selected arrangement is capable of transmitting 3 kW of power while remaining fairly compact. The general embodiment of the vehicle is a two wheeled scooter/skateboard hybrid with 20 cm diameter wheels. The goal was to have the simplicity of 2 wheels from a scooter but the compact lean controlled steering of a skateboard. The design of the steering required a unique kinematic 4 bar mechanism that responds reasonably well at low speeds yet still remains stable at higher speeds. The design phase was assisted with a spreadsheet that models the performance of the finished board based on the chosen battery, gearing, motor, wheel, and rider specifications. This sheet provided everything from top speed and max climbable gradient to estimates of range