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

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

3. 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

4. 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

5. 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.

6. 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

7. 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.)

8. 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