[02.2020]Cruzin' in style: An Electric Trike
Description of Project
In MITERS we have a tradition of building electric vehicles and riding them around campus/cambridge for fun. This projects goal was to create a comfortable, peppy, and robust electric trike while also limiting its top speed for safety.
Processes Applied:
Summary:
The general design requirements of this electric vehicle are as follows:
- ~20 MPH top speed
- Can be stored in my apartment
- Robust against abuse
- Easy to repair
- Long range
- Comfortable
- And most importantly, fun!
Comfort has been one of my biggest complaints with long rides on previous electric scooters and my friends' electric vehicles. Most designs focus on speed and rideability rather than ergonomics. I aimed to prioritize comfort in my design. I started with the seat, opting for a folding boat seat found at a discount on Amazon. Its standard spacing bolt pattern made adaptation easy. Additionally, I experimented with frame design for improved ergonomics.
For robustness and ease of repair, I made careful design choices. Mechanically, I repurposed a sturdy steel BMX bike frame and used sturdy square steel tubing for the back half of the frame. The wheels consist of a cast aluminum front wheel and hoverboard electric wheels for the back, all of which can be hot-swapped. Electrically, I utilized easily replaceable low-cost Chinese E-Bike controllers, each mounted on rubber feet for shock protection. I also ensured easy replacement of the throttle cable assembly.
To achieve the goals of a 20 MPH top speed, long range, and fun, I experimented with motor controller and wheel configurations. By limiting the voltage to the controllers, I maintained a speed of approximately 20 MPH. I optimized the battery pack layout for capacity and range, incorporating high-quality cells donated by a friend. These improvements resulted in better acceleration and increased capacity and range.
Regarding storage, I initially overlooked the requirement but found that the foldable seat and handlebars allowed for convenient storage under a workbench in my apartment.
Overall, despite the challenges, this project was a success. Future upgrades may include electric regenerative braking, improved LED light mounting and visibility, and the addition of chains for winter adventures.
Future Upgrades:
- Electric Regen Braking (Currently front brakes only, which can be problematic for quick stops due to weight distribution)
- Better mounting for LED lights
- Additional LEDs for enhanced visibility and fun
- Winter Ice Lake adventure chains for 2021-2022
Link to video of a friend test-driving the electric vehicle.
