High Powered Electric Scooter

Objective

This project tested both my technical abilities and perseverance, pushing me to overcome numerous challenges to succeed. To date, it stands as one of my proudest achievements and addresses a real, everyday problem in my life.

The inspiration for this project came from a frustrating issue I encountered while trying to secure a parking spot on the busy streets of campus. After failing to obtain a spot through UT Austin's lottery system, I was forced to park several miles away from my classes each morning. As an engineer, my only option was to spend the next 2 months and all the skills and knowledge I had accumulated to create something I'd be proud of

Before diving into sourcing parts and navigating the complexities of development, I outlined clear objectives for the project to ensure I stayed focused and met my goals. These objectives included:

• Low CG while staying maneuverable and stable at high speeds

• Optimized for city riding with powerful brakes and responsive acceleration.

• Suspension less design to minimize complexity and added weight

• 50mph top speed, 15 mile range, & high torque

• Built in lock with antitheft features

• Budget of $1000

Process

The research and design phase of this project spanned a few weeks. Working with a limited budget and access to basic tools, I sketched countless iterations of the design, experimenting with different components both on paper and in Fusion 360. Ultimately, I decided to weld the main frame using mild steel square tubing, reinforced with vertical 1/8-inch gauge sheets to counteract bending forces. For the headset, I repurposed the head tube from a children's bike—a decision that would later lead to significant challenges.

The power system was a critical aspect of the e-scooter's success. I used two 3000W brushless hub motors powered by a custom-built 48V lithium-ion battery and controlled by a high-performance ESC. While the wiring process was relatively straightforward, sourcing a throttle and dashboard setup that was both accurate and reliable proved to be a significant challenge.

After weeks of fabrication and countless late nights, I finally completed a functional electric scooter on the night before the first day of the semester. The initial test runs were unforgettable—the instant acceleration was both terrifying and exhilarating.

Challenges

Although I was confident in my design, believing I had overengineered every component, less than 50 miles into the build, I encountered a devastating failure in the headset assembly. The immense forces applied by the long steering column acting as a lever, sheared the low-carbon steel used in the cheap Walmart kids bike frame. I had to painstakingly grind off the head tube and front fork, reaching a point where I questioned whether I could even salvage the build. Despite hours of research into both DIY designs and commercially available scooters, I found no helpful material capable of withstanding such forces provided the tools I had access too.

After exploring multiple options and facing additional challenges in realigning components, I eventually sourced new bearings and built a custom threadless stem and stem housing, inspired by modern mountain bike designs. I utilized a solid steel compressive clamp, enabling easier maintenance and future repairs without requiring destructive disassembly of the front end.

Since then, the scooter has proven itself through months of hard riding, with over 250 miles logged and daily use, all without further issues or complaints

Future Developments

Although this project was highly successful, outperforming any scooter in its price range and weight class with a top speed of over 50mph and a range of about 15 miles, I am eager to build a Version 2 out of aluminum to make the scooter faster and lighter. Partnering with a designer and scooter enthusiast, I hope to continue improving this design and allow others to enjoy the amazing experience of riding such a machine.

Objectives for V2

• Folding mechanism & smaller footprint to improve ease of transportation

• Aluminum frame, integrating a front and rear suspension

• Longer range & VESC Integration for on the fly throttle calibration

• Built in headlight and tail light