Non-Slip Prosthetic Surf Foot QL+ Project 174A1 CP
Total Page:16
File Type:pdf, Size:1020Kb
ENGR 459-461 Interdisciplinary Senior Design Project Fall/Winter/Spring 2019-2020 Non-slip Prosthetic Surf Foot QL+ Project 174a1 CP Sabrina Nelson - [email protected] Ryan Monjazeb - [email protected] Gerrit Sperling - [email protected] Luis Mata - [email protected] College of Engineering California Polytechnic State University, San Luis Obispo 2019 - 2020 ENGR 459-461 Interdisciplinary Senior Design Project Fall/Winter/Spring 2019-2020 Statement of Disclaimer This project is a result of a class assignment, and it has been graded and accepted as fulfillment of the course requirements. Acceptance does not imply technical accuracy or reliability. Any use of information in this report is done at the risk of the user. These risks may include catastrophic failure of the device or infringement of patent or copyright laws. California Polytechnic State University at San Luis Obispo and its staff cannot be held liable for any use or misuse of the project. ENGR 459-461 Interdisciplinary Senior Design Project Fall/Winter/Spring 2019-2020 Table of Contents List of Tables 1 List of Figures 2 - 3 List of Nomenclature 4 Executive Summary 5 Introduction 6 Background 7 - 12 Objective 10 Design Development 13 - 17 Final Design Concept 16 Detailed Description of Final Design 18 - 25 Material Selection 20 Coefficients of Friction Test for Polyurethane Samples 20 FEA Analysis Results 21 Cost Breakdown 23 Safety Considerations 25 Maintenance and Repair consideration 25 Product Realization 26 - 27 Design Verification 28 Conclusions and Recommendations 29 Acknowledgements 30 References 31 Appendices 32 - 70 Appendix A. Comparison of surf waxes 32 Appendix B. QFD and Decision Matrices 33 - 35 ENGR 459-461 Interdisciplinary Senior Design Project Fall/Winter/Spring 2019-2020 Appendix C. Final Drawings 36 - 50 Appendix D. List of vendors, contact information, and pricing 51 Appendix E. Vendor supplied component specifications and data sheets 52 - 54 Appendix F. Further FEA Analysis 55 - 56 Appendix G. Initial Rubber Pour 57 Appendix H. Detailed Manufacturing Plan 58 - 59 Appendix I. Detailed Test Plans 60 - 66 Appendix J: Images of 3D printed molds 67 - 68 Appendix K. Gantt Chart 69 Appendix L. Safety Checklist 70 List of Tables Table I: Surf Foot Formal Engineering Requirements 12 Table II: Measured Coefficients of Friction 21 Table III: Breakdown of Total Project Funds 24 Table IV: Tests and Inspections to be Completed on Assembled Prosthetic 28 Table V: Quality Function Development (QFD) 33 Table VI: Pugh Matrix to Compare Concepts 34 Table VII: Foot Sleeve Decision Matrix 35 Table VIII: Vendor Information 51 1 ENGR 459-461 Interdisciplinary Senior Design Project Fall/Winter/Spring 2019-2020 List of Figures Figure 1. Photo of where Dana’s slipping problem occurs 7 Figure 2. Rush Foot Rogue, available for purchase 8 Figure 3. Assembly of last year’s Senior Project design for Surf Leg 9 Figure 4. Current modified prosthetic leg used by Dana while surfing 9 Figure 5. Fillauer All Pro Foot, the prosthetic Dana currently has 10 Figure 6. Flat edge design 13 Figure 7. Curved edge design 13 Figure 8. Modified Rush Foot design 14 Figure 9. Spring design 14 Figure 10. Ankle adapter design 15 Figure 11. SolidWorks model of design presented to Dana (curved edge) 16 Figure 12. Titanium Foot Pyramid Adapter 18 Figure 13. Isometric view of prosthetic design 19 Figure 14. Front view of prosthetic 19 Figure 15. FEA for stresses on Surf Foot with 100 lbs applied 21 Figure 16. FEA for stresses on Surf Foot with 600 lbs applied 22 Figure 17. FEA for deflection on Surf Foot with 100 lbs applied 23 Figure 18. Solid model of mold for foot component 26 Figure 19. Set up of heel-side rubber mold before pouring liquid urethane 27 Figure 20. Final rubber components prior to post-processing 27 Figure 21. Comparison of three different surf waxes 32 Figure 22. Detailed Drawing of Assembly with Bill of Materials 36 Figure 23. Detailed Drawing of Foot Part 37 Figure 24. Detailed Drawing of Pylon Part 38 2 ENGR 459-461 Interdisciplinary Senior Design Project Fall/Winter/Spring 2019-2020 Figure 25. Detailed Drawing of Rubber Toe Part 39 Figure 26. Detailed Drawing of Rubber Heel Part 40 Figure 27. Detailed Drawing of Bottom Mold for Foot 41 Figure 28. Detailed Drawing of Top Mold for Foot 42 Figure 29. Detailed Drawing of Outer Mold for Pylon 43 Figure 30. Detailed Drawing of Inner Mold for Pylon 44 Figure 31. Detailed Drawing of Bottom Outer Mold for Rubber Toe 45 Figure 32. Detailed Drawing of Top Outer Mold for Rubber Toe 46 Figure 33. Detailed Drawing of Inner Mold for Rubber Toe 47 Figure 34. Detailed Drawing of Bottom Outer Mold for Rubber Heel 48 Figure 35. Detailed Drawing of Top Outer Mold for Rubber Heel 49 Figure 36. Detailed Drawing of Inner Mold for Rubber Heel 50 Figure 37. FEA of deflection on Surf Foot with 600 lbs applied 55 Figure 38. FEA of stresses at the adapter of Surf Foot with 300 lbs applied 55 Figure 39. FEA of bolt stresses on Surf Foot 56 Figure 40. Toe-side result of initial pour 57 Figure 41. Heel-side result of initial pour 57 Figure 42. 3D printed foot mold 67 Figure 43. 3D printed pylon mold 67 Figure 44. 3D printed toe-side rubber mold 68 3 ENGR 459-461 Interdisciplinary Senior Design Project Fall/Winter/Spring 2019-2020 List of Nomenclature CES database: Virtual library that contains important technical data on thousands of materials COMSOL: Multiphysics simulation software Dorsiflexion: Movement of raising the foot upward toward the shin FEA: Finite element analysis Liquid urethane: liquid material that becomes rubber (polyurethane) once cured ksi – kilo pound per square inch Plantar flexion: Movement of the foot when it is bent at the ankle away from the body Socket: Connects the residual limb to the prosthetic SolidWorks: Solid modeling computer-aided design (CAD) and computer-aided engineering (CAE) program Transtibial: Below-the-knee 4 ENGR 459-461 Interdisciplinary Senior Design Project Fall/Winter/Spring 2019-2020 Executive Summary The Surf Foot project was created to resolve the challenges faced by Dana Cummings, a former Marine and transtibial left leg amputee, while surfing. Dana is a competitive surfer who first picked up the sport after he lost his leg. He currently utilizes a carbon fiber prosthetic leg when surfing. However, this prosthetic is not ideal for Dana as he often slips while standing up on his surfboard. As such, Dana would like a new non-slip prosthetic leg so that he can further pursue his passion of competitive surfing. Our team, which consisted of four engineering students attending Cal Poly, San Luis Obispo, was sponsored by the QL+ organization. Over the course of three quarters, we worked to research, design, manufacture, and test a prototype that would meet Dana’s requirements. After several months of brainstorming and conceptualizing, we designed a prosthetic leg made from five main components. These components include two pieces of carbon fiber which together serve as a leg, two rubber components intended to serve as a non-slip sole for the prosthetic, and an adapter that would allow Dana to attach the prosthetic to the socket he uses when surfing. Unfortunately, due to the closure of on-campus facilities that resulted from the COVID-19 pandemic, our team was unable to complete the manufacturing and in-person testing of the prosthetic we designed. Instead, we compiled a list of in-depth instructions regarding the planned manufacturing process and testing of our design so that a future QL+ team could complete our project once campus facilities reopen. Although we were unable to produce a final product, our team is confident that our design will eliminate Dana’s problem of slipping while surfing, thus enabling him to further pursue surfing as a competitive sport. 5 ENGR 459-461 Interdisciplinary Senior Design Project Fall/Winter/Spring 2019-2020 Introduction Dana Cummings is a below-the-knee left leg amputee who lost his leg in a vehicle accident after serving in the United States Marine Corps. Dana didn’t allow his circumstances to stop him from living an active lifestyle and following the accident he began to learn how to surf. As he progressed in surfing, he founded the organization AmpSurf in an effort to bring the joys of surfing to others with disabilities. AmpSurf aims to promote, inspire, educate, and rehabilitate disabled veterans, adults, and children by showing them what they are capable of doing as opposed to focusing on their disabilities. They offer surfing clinics to hundreds of these individuals “to bring the healing power of the ocean for an experience that is both mentally and physically one of the best forms of rehabilitation on the planet” [1]. The more advanced Dana’s surfing became, the more he recognized the limitations of surfing with his prosthetic. He went to QL+, an organization committed to bettering the quality of life for those with physical disabilities, with an idea to minimize the challenges associated with surfing while utilizing a prosthetic leg. He requested a non-slip surfing foot that would allow him to stand up while catching a wave, prevent his foot from slipping toward the back of the board, and provide him with more points of contact with the surfboard to assist him in doing more complex maneuvers. Our team, appropriately named “Surf Foot”, consists of two Biomedical Engineering students, Ryan Monjazeb and Sabrina Nelson, a General Engineering student, Luis Mata, and a Manufacturing Engineering student, Gerrit Sperling. As a team, and with the help of our advisor Jim Widmann, we plan to realize Dana’s dream of a non-slip prosthetic surfing foot to enhance his surfing experience.