1. Design Review
Off-Road Wheelchair
Project

2. 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

3. 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.

4. Deliverables A customized off-road wheelchair Design Drawings
Assembly instructions
Engineering Analysis

5. 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

6. Wheelchair Experience
Quickie 2
Special Needs Baby Jogger

7. Off-Road Wheelchair Models
Quickie XTR
Natural Access
De-Bug

8. Available Accessories
Wheel Rims
Quick Release Hubs
Castors
Seating Upholstery
Mountain Bike Tires

9. Design Philosophy: What drives the design? Safety and Stability
Overall Convenience
Cost

10. Design Method
Modeling

11. Wheel Sizes

12. 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

13. Design Evolution Design #2 Features: Folding X-Member
16’’ Rear Castors
16’’ Front Tires
Problems:
Rear Castors
Steering Difficulty
Curb Navigation
Difficulty Collapsing

14. Design Evolution Design #3 = Frozen Design Features: Seatback Folds
Elevated Footrest
20’’ Rear Tires
12’’ Front Castors
Quick Release rear tires

15. Design Evolution
Moving
Stationary for Transfers

16. Design Evolution
Wheelchair Folded
Castor Wheel

17. Frame Material - Aluminum 5052
Corrosion Resistant
Weldability
Availability
High Strength-Weight Ratio
Tinius Olsen Tension Test
Su = 24,000 psi
Sy = 16,000 psi

18. Determining Design Load
Static Load = 150 lbs
Shock Load
Worst Case Amplification Factor = 2
Results in 300 lbs Dynamic Load

19. FEM - Loads and Displacements

20. FEM – Max Stress

22. FEM – Deflection and Contour Stress
s’ = 5,700 psi
F.S. = 2.8
Points of
Max Stress

23. 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

24. Schedule Followed

25. 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

26. Spring Semester Team Timesheet
Week Hours
Total Weekly Avg: 41.8

27. Bill of Materials and Cost Estimate

28. 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

29. Summary Design Finalized Ready to Begin Manufacturing
Funds are in Place
Wheelchair Delivered May 2

30. Questions?