McDonald's Go-Kart
Fall 2022 ~ 4 Person Collaboration
Team Picture with Go-Kart
The Drive
Fully Assembled Go-Kart
Final CAD
Overview
In this project, I wanted to learn more about automotive design elements, with key emphasis on the design speed and controllability of the automobiles.
Objectives
- Small turn radius
- High controllability
- High ergonomics
- Fast max speed
Skills
Mechanical Design: SolidWorks CAD
Manufacturing: 3D Printing, Laser Cutting, Shop Tools, Fasteners and Adhesives
Key Tasks
Each member on the team focused on specific subassemblies, which were integrated at the end. I was responsible for the chassis and the steering subsystems.
Initial Trapezoidal Chassis Concept Sketch
Chassis (Top View)
Chassis (Isometric View)
Chassis:
- Designed and tested 16" x 51" a chassis capable of supporting 200 lbs of driver weight, guarding the passenger and other components, and integrate with other subassemblies with minimal interference.
- Moved from trapezoidal frame to a rectangular frame for more leg area and ease of manufacturing (Design for Manufacturing).
Steering System CAD
Steering Shaft Collar
Physical Steering Rod with Adjusted Placement
McLovin' Steering Wheel
Steering:
- Iteratively prototyped a mechanical steering system to maximize steering authority, adjusted steering slot on the upright until we achieved neutral front wheel camber but offered 30+ deg of steering.
- Test high-infill (up to 70%) 3D-printed gussets to secure uprights and wheels to reduce flexing under driver load.
Main Challenges
Clearances of various 3D-Printed parts → sanding and filing down to size
Too big toe angle → cut down steering rod
Not enough steering control authority → created new holes to reduce steering arm and increase authority
Poor grip between motor and belt when driver weight applied → increased belt tension and reassembled drivetrain more securely to reduce wobbling
Structural issues → increase infill and change materials
Drivetrain Assembly
Brake Paddle
Outcomes
- Fun to drive around parking lots!
- Up to 30 mph top speed, and tight turn radius of 2 ft.
