Design Review Off-Road Wheelchair Project
Mobility Solutions Team Scott Turnbull - Team Leader Brett Bonner - Assistant Team Leader Roy La Barbera – Treasurer Joey Speigl – Communications Dr. John Tester - Advisor Our Clients Carol Seumptewa Toni Seumptewa
Problem Statement Clients enjoy the outdoors Current wheelchair unsuitable Past search was unsuccessful Our objective is to design and build a safe and reliable off-road wheelchair.
Deliverables A customized off-road wheelchair Design Drawings Assembly instructions Engineering Analysis
Functional Requirements Safely, Easily Traverse Dirt Trails Facilitates Passenger Pivot Transfers Comfortable, Upright Seating Position Passenger Restraint System Braking System Low Maintenance Lightweight and Fit Into Client’s Truck
Wheelchair Experience Quickie 2 Special Needs Baby Jogger
Off-Road Wheelchair Models Quickie XTR Natural Access De-Bug
Available Accessories Wheel Rims Quick Release Hubs Castors Seating Upholstery Mountain Bike Tires
Design Philosophy: What drives the design? Safety and Stability Overall Convenience Cost
Design Method Modeling
Wheel Sizes
Design Evolution Design #1 Features: Folding X-Member Swinging Arms w/ Castors 26’’ Rear Tire 12’’ Front Castor Problems: Too many moving parts Questionable reliability
Design Evolution Design #2 Features: Folding X-Member 16’’ Rear Castors 16’’ Front Tires Problems: Rear Castors Steering Difficulty Curb Navigation Difficulty Collapsing
Design Evolution Design #3 = Frozen Design Features: Seatback Folds Elevated Footrest 20’’ Rear Tires 12’’ Front Castors Quick Release rear tires
Design Evolution Moving Stationary for Transfers
Design Evolution Wheelchair Folded Castor Wheel
Frame Material - Aluminum 5052 Corrosion Resistant Weldability Availability High Strength-Weight Ratio Tinius Olsen Tension Test Su = 24,000 psi Sy = 16,000 psi
Determining Design Load Static Load = 150 lbs Shock Load Worst Case Amplification Factor = 2 Results in 300 lbs Dynamic Load
FEM - Loads and Displacements
FEM – Max Stress
FEM – Deflection and Contour Stress s’ = 5,700 psi F.S. = 2.8 Points of Max Stress
Fatigue Analysis Weight Estimate Stability Analysis 25 Degree Slopes Sf = 16,000 psi (500 million cycles) F.S. = 2.8 Weight Estimate 20 – 30 lbs Stability Analysis 25 Degree Slopes
Schedule Followed
Where We Are Behind Schedule Approximately 1.5 Weeks Behind Locating Vendors (Mostly Complete) Order Ready-Made Parts Weld Frame Use of Time and Manpower Assigned Design and Analysis Tasks Manufacturing Tasks To Be Assigned
Spring Semester Team Timesheet Week Hours 1 20.3 2 50.6 3 36.1 4 45.7 5 71.0 6 36.8 7 51.7 8 22.0 Total 334.2 Weekly Avg: 41.8
Bill of Materials and Cost Estimate
Fundraising Cost Tracking ASNAU - $360 DDD - $300 Doney Park Water - $700 Cost Tracking CET Account Setup Receipts to Treasurer and Reimbursement Notify Client to Write Check
Summary Design Finalized Ready to Begin Manufacturing Funds are in Place Wheelchair Delivered May 2
Questions?