Electric Kick Scooter "Skip"
An electric kick scooter built from the chassis to the electronics
Overview
An electric kick scooter I designed myself, from the frame to the electronics. It is something I could simply have bought, but I chose to build it, fitting it out for public roads with brake lights, turn signals, and a license plate mount.
Why I built it
Robot competitions had given me experience with mechanics, circuits, and software, but a vehicle that carries a person brings design constraints of a different order: strength, safety, and the law. Half the motivation was practical, wanting a way to get around. The other half was to test whether I could design a complete vehicle entirely on my own, safety equipment included.
The vehicle
The frame and steering were designed in Autodesk Inventor. For the electronics, I designed the boost converter circuit in LTspice and made the circuit board myself. Safety equipment was part of the design from the start: a headlight, brake lights, homemade LED ring turn signals, and a license plate mount.
CAD design of the homemade safety equipment unit, integrating the tail light, brake light, reflector, and plate mountWith a robot, you can prototype, break things, and repeat. For a vehicle that carries a person, that approach does not hold. For the power circuit I followed a more careful procedure than usual, verifying its behavior in simulation before building it.
Front of the finished vehicle, with the headlight and homemade LED ring turn signals lit 
Full side view, showing the rear hub motor and homemade control box 
The finished vehicleLegal compliance
The license plate that was issuedSince the scooter was meant for public roads, I put particular effort into legal compliance. I went through the relevant statutes and ministerial ordinances one by one and reflected them in the design so that every piece of safety equipment would meet the standards without question. Alongside that, I wrote my own documentation demonstrating compliance item by item. By the end, it amounted to a considerable stack of paperwork.
The specification documents I prepared 
Documents demonstrating compliance with the safety standardsWith the license plate mounted, in front of the Kinkaku-ji gateUnlike a robot, something a person rides is not finished just because it is built and running. This project gave me the experience of completing a vehicle in full, legal requirements and paperwork included.