Secure Bike Rack
Senior Capstone Design Project, Spring 2015
For my senior mechanical engineering capstone project, I worked with Mike O'Connor, Alvan Mbongo, and Christian Heaney-Secord to design a safer, more secure vertical bike rack. At the senior Mechanical Engineering Design Expo, the bike rack won best prototype. Our design process is highlighted in our expo poster.
A product need was identified based on the fact that 1.5 million bikes are stolen every year. Standard locking mechanisms, such as U-locks, cable locks, and chains face tradeoffs between strength, weight, cost, and ease of use. Integrating locking mechanisms into bike racks will allow for optimizations in lock strength and security. By discouraging bike theft, bikers will feel better about locking their bikes in public places. Social benefits of this initiative include promoting healthy transportation, decreasing city traffic congestion, minimizing pollution, and reducing bicycle related crime.
The final product protects the frame, front, and back wheel of almost any sized bike. The user rolls his or her bike into a vertical bike rack, shaped to secure the wheels. A locking claw grasps the frame on contact, securing the bike. The rider then inputs a password onto the attached keypad, finalizing the locking process. A solar panel keeps the entire system off the grid. A foot pedal allows the user to lock their bike while stabilizing it with both hands. Creating such a stationary locking system will decrease bike theft and improve lock security compared to current market options.
The team was successful in creating a proof of concept, full scale prototype. Tradeoffs were made between cost, manufacturability, and security in order to keep the project within scope. Tested around the Carnegie Mellon campus, students were able to lock bikes with a 100% success rate. Users found the vertical locking motion simple and intuitive; the motion needed little practice to perfect. Future work includes preparing design for manufacturability and confirming security with a professional locksmith.
My project responsibilities included
- Analyzed product opportunity gaps to identify the need for a more secure bike rack
- Interviewed stakeholders and studied use cases to create product requirements
- Used rapid prototyping tools to test design concepts
- Modeled bike rack in Solidworks and optimized components through FEA studies
- Manufactured prototype using mills, lathes, laser cutters, and other shop tools
- Designed system using motor controllers, buttons, a keypad, and an arduino
- Tested device around Carnegie Mellon campus with 100% success rate
- Managed budget of $750