Building an electric scooter
Design
Since coming to MIT, I have always wanted to build an electric scooter. All the cool kids have one, and it would be a really convient way to get around campus. I decided to build one with two friends. We wanted to do something different and not just rehashed the same design.
The frame is made out of scrap pieces of metal pipes, 8020 aluminum, and waterjetted aluminum plate. The scooter has a rear suspension system. The back wheel is placed on a separate pivot joint. A spring holds the rear wheel against the base. This allows the back wheel to swing around the pivot point and absorb energy from any sudden ground level change.
We wanted to ride the vehicle both standing up and sitting down. To do this, we made the handle bar really high - think Ape Hangers of a motorcycle. This means we can sit on the scooter and reach up onto the handle bar, or stand and can still comfortably reach the handle bar.
The installed electric motor is rated for 2kW. The motor drives the back wheel through a chain and sprocket. After riding the scooter for a while, we noticed that the scooter will forcibly slow down if you let go on the throttle. To solve this problem, we added a freewheel on the hub of the motor. The battery is mounted on the bottom of the frame. An polycarbonate case houses the battery to protect it. Sitting behind it is a motor controller.
First spin-up from a power supply:
Test Run
Here’s a video of the vehicle running the first night we got it working: