Project Number: ME-CAB-0914 Design of a Hands-Free Rotating Snowboard Binding Device A Major Qualifying Project Report Submitted to the Faculty of the WORCESTER POLYTECHNIC INSTITUTE in partial fulfillment of the requirements for the Degree of Bachelor of Science in Mechanical Engineering by Patricia Adamson ______________________ Marina Gurbanov ______________________ Whitney Rock ______________________ Date: June 11, 2007 Approved: _____________________________ Prof. C. A. Brown, Major Advisor keywords 1. Cam design 2. snowboard binding 3. rotation Abstract The goal of this project was to design, build, and test a rotating snowboard binding that allows a snowboarder to rotate their leading foot to a comfortable angle and that reduces the injuries due to torque from external forces to the snowboard. Currently, there are no snowboard bindings on the market that allow a user to rotate their feet hands-free and none that can prevent or reduce twisting injuries which are not releasable bindings. SolidWorks was used to create a 3D solid model of the design, which included a Cam and spring mechanism to allow rotation in 90-degree increments. A prototype was built using CNC machines and tested by using a torque wrench to determine the torque needed to twist the Cam into an adjacent position. The prototype was also tested at Wachusett Mountain to ensure normal snowboarding function while entering and exiting the ski lift and riding down the mountain. Since the prototype was successful, the team is seeking a patent or a company interested in purchasing the design. ii Table of Contents Abstract............................................................................................................................... ii Table of Contents...............................................................................................................iii Table of Figures ................................................................................................................. iv 1 Introduction................................................................................................................. 1 1.1 Objective............................................................................................................. 1 1.2 Rationale ............................................................................................................. 1 1.3 State-of-the-Art................................................................................................... 1 1.4 Approach............................................................................................................. 2 2 Design Decomposition and Restraints........................................................................ 4 2.1 FR 1 œ Attach Boot to Board.............................................................................. 5 2.2 FR2 Allow Rotation of Binding.......................................................................... 7 2.3 FR3 Adjustable Torque....................................................................................... 9 3 Description of Parts................................................................................................... 11 3.1 Base Plate.......................................................................................................... 11 3.2 Top plate œ Cam................................................................................................ 13 3.3 Spring Mechanism ............................................................................................ 15 3.4 Side plate œ Tightening Mechanism ................................................................. 17 3.5 Manufacture ...................................................................................................... 18 3.6 Hardware........................................................................................................... 19 4 Testing and Analysis................................................................................................. 20 4.1 Prototype Assembly.......................................................................................... 20 4.2 Modeling of Torques and Displacements ......................................................... 22 4.3 Mechanical Testing of Torques and Displacements ......................................... 23 4.4 On-Slope Testing.............................................................................................. 25 5 Iteration..................................................................................................................... 26 6 Discussion................................................................................................................. 27 7 Conclusions............................................................................................................... 30 References......................................................................................................................... 31 Appendix A œ Line Drawings........................................................................................... 33 Appendix B œ Brief History of Snowboarding................................................................. 39 Appendix C œ Poster ......................................................................................................... 40 Appendix D œ Calculations and Measurements................................................................ 41 Appendix E œ Maximum Torque by Weight œ Bally and Taverney................................. 46 Appendix F œ Ski Binding Release Values....................................................................... 47 iii Table of Figures Figure 2-1............................................................................................................................ 4 Figure 2-2............................................................................................................................ 6 Figure 2-3............................................................................................................................ 6 Figure 2-4............................................................................................................................ 7 Figure 2-5............................................................................................................................ 8 Figure 2-6............................................................................................................................ 8 Figure 2-7............................................................................................................................ 9 Figure 2-8.......................................................................................................................... 10 Figure 3-1 œ Assembled Design........................................................................................ 11 Figure 3-2 œ Base.............................................................................................................. 13 Figure 3-3 œ Top Plate/Cam.............................................................................................. 14 Figure 3-4 œ Spring Mechanism & Side Plate .................................................................. 16 Figure 3-5 œ Controller ..................................................................................................... 17 Figure 3-6 œ Side Plate...................................................................................................... 18 Figure 4-1 œ Photo of Assembly....................................................................................... 20 Figure 4-2 œ Spring Mechanism ....................................................................................... 21 Figure 4-3 œ Top plate/Cam.............................................................................................. 21 Figure 4-4 œ Theoretical Torque vs. Angle....................................................................... 22 Figure 4-5 œ Torque Wrench Attachment Piece ............................................................... 23 Figure 4-6 œ Measured Torque vs. Angle ......................................................................... 24 Figure 4-7 œ Maximum Calculated and Measured Torques ............................................. 25 Figure A-1 œ Cam ............................................................................................................. 33 Figure A-2 - Base.............................................................................................................. 34 Figure A-3 - Plunger ......................................................................................................... 35 Figure A-4 œ Controller .................................................................................................... 36 Figure A-5 - Side Plate ..................................................................................................... 37 Figure A-6 - Torque Wrench Adapter .............................................................................. 38 Figure C-1 - MQP Poster .................................................................................................. 40 Figure E-1 œ Maximum Snowboarding Torques .............................................................. 46 Figure F-1 œ Ski Release Value Selection........................................................................ 47 iv 1 Introduction 1.1 Objective The objective of this project is to design, build, and test a rotating snowboard binding that will