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Systems Level Design Review. Jib Transfer Bench – P13031 1/11/2012. Agenda. Problem Definition Customer Needs / Specifications Functional Decomposition Benchmarks First CAD Design Concept Generation Selection Criteria Matrix Preliminary Calculations Budget Estimate Project Plan.
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Systems Level Design Review Jib Transfer Bench – P13031 1/11/2012
Agenda • Problem Definition • Customer Needs / Specifications • Functional Decomposition • Benchmarks • First CAD Design • Concept Generation • Selection Criteria Matrix • Preliminary Calculations • Budget Estimate • Project Plan
Project Definition • Task is to design a mechanical solution to move a disabled jib trimmer from side to side so they can perform their crew function
Customer Needs & Specifications SEE METRICS CHART
Individual Specific Customer Needs • Gary & Zak • No leg mobility / core support • Desires to be fully secured • Cindy • Partial leg & core strength • Desires freedom to exit seat • Limited footprint available due to Richard’s chair • Height differences to consider
Method of Motion Across Boat • Must be able to translate AND rotate independent of each other (i.e. not fixed)
Seat Bracket Top Travel Bars Bottom Travel Bar Seat Traveler Support Bar Platform
Handhold locking mechanisms • Handhold mechanisms on the previous team’s captain’s chair
Handhold locking mechanisms • We plan to use something similar to secure our device to the front handholds to the boat
Concept Generation • Brainstormed ideas for each main component of our assembly: • Seat • Method of motion (translation and rotation) • Method of propulsion • Harness • Locking mechanism • All must fall within our size constraints for Richard’s boat and without extending into the other team’s footprint
Method of Motion (cont.) • Concept: Chair that can rotate on a pair of rails spanning the boat • Problem: With full 180° rotation, legs will smack
Method of Motion (cont.) • “Seat-Within-A-Seat” initial sketch • Swivel chair on rails that span the boat One bar w/ bottom support Two bar w/o support
Method of Motion (cont.) • Telescoping arm anchored on the boat floor (platform) • Seat mounted on top of arm
Method of Propulsion • Jib trimmers with limited core strength • Propel themselves linearly • Rotate themselves • No electrical solution, 100% mechanical
Method of Propulsion • Settled on a purchase system • Pulley system that will allow the user to pull themselves with a mechanical advantage
Locking Mechanism (Chair) • Currently, not settled on a specific lock. • Fence lock, pin lock, friction plate • Cleating purchase system lines to lock chair • Check prices • Check compatibility of what we want to do
Seat Concepts • Must support jib trimmer’s • Torso • Legs • Should have capability to accept and secure a user’s wheelchair cushion should they wish to use it.
Benchmark - Team Paradise’s Seat • Lazy Susan design
Seat Designs • Swivel Stool Go-Kart Seat Racecar Seat
Harness • 5-point harness • Secured Double-Velcro vest • Lap Belt
Selection Criteria Matrix Compiled all ideas, determined the best: • “Seat-Within-A-Seat” Chair • Harness or double-Velcro vest • Purchase system for motion • Undetermined locking mechanism • See Excel file
Selection Criteria • Two separate systems based on individual customer needs
Zak & Gary • Go-Kart Seat
Cindy • Stool
Preliminary Calculations • Calculations to prove the design: • Using aluminum traveler bars • Box tube deflection – 7075 Aluminum • Weight sitting on • Deflection: -0.0000131 inches • Shears at 19.9° • Box tube shear strength • Looking at smaller, cheaper, lighter materials
Drawing • Assuming 260-lb human
Sailboat Installation • Drop platform onto floor • Lock into first handhold (using similar locking device from Gold Medal Chair) • Jib trimmer sits in chair and straps in • Sail away!
Budget Estimate • Based on the Gold Medal Chair: • $1,658 • Based on research of components that we are looking at: • $2,000
Project Plan Summary • Continue with design phase • CAD Modeling • Create Bill of Materials • Prove Design • Detailed Design Review in 3-5 weeks • Order parts • Build, install, sail!