Mechanical Engineering Department
BS in Mechanical Engineering
James Widmann, J. Kevin Taylor
The RAPD program is a federal organization funded by the National Science Foundation that supports the development of technologies for new and improved devices or software for persons with disabilities; in the case of our project and our fellow classmates, the program provided grants to student projects that are designed to help persons with disabilities in participating and enjoying physical activity. Our project is directed with the help of Dr. Widmann and Dr. Taylor of the Mechanical Engineering and Kinesiology Departments respectively, at California Polytechnic State University, San Luis Obispo. Three students from the Mechanical Department and one student from the Kinesiology department have been tasked with the design of this unique mobility walker to assist a local 8-year old Special Olympian. The walker makes use of lightweight materials, specialized balloon beach tires, and a very rigid frame to ensure safety, longevity and overall aesthetic appeal.
This report details the idea generation, concept selection, calculations and design of a mobility walker for traversing the beach environment. The design that the team implemented is a direct influence from Sean’s current beach walker, his general purpose walker and other existing designs that were researched. Our final design was fabricated at a total cost of approximately $850, which was significantly reduced due to generous donations from multiple suppliers. Despite the success of our final product, a few minor improvements could be made to the design. The pipe fittings used to connect the various components of the frame are slightly too big and result in a loose fit with the tube. A new clamp could be selected to help eliminate any clearance that may affect the overall function and strength of the walker. In addition, the weight could be reduced through the use of thinner wall aluminum tube and the caster could be fabricated by bending thicker aluminum as opposed to the welded design we produced. A final recommendation for improvement is making the foam padding more secure by fastening it directly to the frame to eliminate chances of slipping while Sean is in the water.
The primary features of the final design include:
1. High surface area, low pressure, polyurethane balloon tires that are specialized for beach environment are used to allow easy traverse across sand and other comparable terrain. In addition, they provide significant stability and buoyancy while in the water.
2. The handlebars can be adjusted to accommodate Sean’s growth.
3. The frame is powder coated and fastened using corrosive resistant hardware to prevent rust from developing, increasing the life and overall functionality of the walker.
4. The front wheels utilize a caster and bushing assembly that makes turning and maneuvering through the sand easier.