Team P09009 One-Arm Wheel Chair System Level Design Michelle Allard Sean Bodkin Deborah Chen Nicholas Rehbaum Bradley Stroka Alex Vogler

Final Specifications EDGE Website and View “Final Specifications” under Week 4

System Designs Evaluation EDGE Website and View “System Designs Evaluation” under Week 4 Zip Tie and Lever Differential were highest rated systems Highest rating among the highest weighted specifications were used as a tie-breaker for the systems Chosen system: Lever Differential

Risk Assessment Risk Assessment Lever Diff. Concept Risk Item Level Owner Status/Contingency Plan Decision Date Folding Chair [Performance/Schedule] High ME's with IE contribution Solution of this issue is integral to this concept design / Possibly chose different design 1/16/2009 Orientation of Braking Handles [Performance] Low Team Possible design sketched/ should be able to solve through design and brainstorming 1/30/2009 Lever Height [Performance] IE's with ME contribution Power vs. Ergonomic issue with shoulder angle / solvable with design 1/31/2009 Lever Interaction with Differential [Performance] Med ME's Mechanical issue / solved through design and force analysis Material Selection [Cost/Performance] Weight and cost will be affected by material selection 2/13/2009 Levels: High Critical needs to be addressed in the near future, jeopordizes progress Medium Impacts project not an immediate deterent to progress Low smaller component issues needing solutions but in no way jeopordizes short or intermediate progress Risks: Performance Schedule Cost

FMEA Subassembly Part/Function Failure Mode Failure Cause Failure Effect Risk Assesment Remarks Severity Prob. Wheelchair Frame Frame Bending Overloading (>250lbs), Improper Use Wheelchair is less durable. Seat may be uncomfortable. 2 4   Weld Failure Overloading (>250lbs), Weak weld Wheelchair is less durable. User can fall off. 6 3 Larger welds, no voids Braking System Manual Breaks Wear/ Tear Break pads are worn (bad contact with wheel) Cannot maintain stationary on level surface or ramp, possible injury Brakes seize or drag Misalignment/ corrosion One or both wheels would require more force to propel. 5 Wheel System Wheel Wheels are worn from normal use or use on rough terrain. Difficult to maneuver Durable wheels Flat (material) Object puncturing tire. Assumes an inflatable tire.

FMEA (Cont’d) Subassembly Part/Function Failure Mode Failure Cause Failure Effect Risk Assesment Remarks Severity Prob. Drive System Chain Misaligned Object gets caught in chain. Wheelchair unable to be propelled by lever. 7 2 Design so chain not low to ground.   Chain breaks Extreme force applied. Wear-resistant material Point between Lever and drive system Bending Seat Seat Fabric Torn/ Frayed Normal wear and tear, overloading (>250lbs) May not be able to handle as much weight as specified, possible injury. 8 5 Durable fabric

Design Review (What do we want to get out of our review?) (From Ryan: A specific summery of what you want to get out of your design review, or what questions/weaknesses you want feedback on. An agenda for design review, with invitees who will be able to provide the subject matter expertise you need.)

Design Review Agenda Attendees: Guide: Matthew Marshall Project Manager: Bradley Stroka Lead Engineer: Alex Vogler Team Members: Michelle Allard - ME Sean Bodkin - IE Deborah Chen - IE Nicholas Rehbaum - ME