Alternative Terrain Wheelchair

Team # 1: Team ARROW

Brent Fischer

Mitchell Kane

Eric Goyette

Brennan McVeigh

Chris MacKenzie

Outline

Current Wheelchairs Design Requirements Considered Designs Selected Design Frame & Drive Budget & Schedule

2

Current Wheelchairs

Indoor Use Favored No Suspension No Gearing Soft Tissue Damage

3

[Clipart] - Wheelchair

Alternative Terrain Wheelchair

Braking Capabilities Gearing Suspension Repairable With

Bicycle Components

Ability To Reverse

4[SolidEdge] – Full Wheelchair

Considered DesignsOff-Axle Crank Drive

Advantages

Proven concept [VarnaHandcycle.com]

Fluid Hand Motion Constant Propulsion

Disadvantages Smaller Moment Arm Accessibility Issues Snag And Pinch Hazard

5

[SolidEdge] – Off-Axle Crank Design

Considered DesignsSame Axle Wheel Drive

Advantages No Learning

Curve Familiar Design

Disadvantages Too Many Chains Snag Hazard Unnatural Motion

6[SolidEdge] – Same Axle Wheel Drive

Considered DesignsGears with Lever Drive

Advantages Ease of Reverse Many Gear Ratios Large Moment ArmDisadvantage Complicated

Design Difficult to

Manufacture Difficult to Repair

7[SolidEdge] – Gears with Lever Drive

Selected DesignChains with Lever Drive

Advantages Easy to Repair Ergonomic

Controls Low CostDisadvantages Reverse has No

Mechanical Advantage

Requires Clutch

8

[SolidEdge] – Chains with Lever Drive

Selected DesignFeatures: Roll Bar Adjustable Legs Rests Bench Press Style

Motion Many Standard Bike

Components Geared Drive

9[SolidEdge] – Full Wheelchair

Suspended Rear Wheels 29” Treaded Tires Mountain Bike

Suspension Independently

Driven Wheels Outer Hand Rims

10[SolidEdge] – Rear Suspension Picture of Shock-absorber

Frame Details Collapsible, Two

Folding Cross Members

All Aluminum Construction

1” Square Tubing

11 [SolidEdge] – Frame

Picture of Tubing

Calculations - FEA

Safety Factor of at Least 5

Impact Load Factor of 3

Bending Side Loading Angled Loading Design

Considerations

12 [SolidEdge] – FEA

Removable Seat

Two Piece Seat Aluminum Framed Weather Resistant Locks on Frame

13[SolidEdge] – Removable Seat

Adjustable Foot Rests

Removable Adjustable Independent Convenient for

Amputees

14

[SolidEdge] – Foot Rests

Safety System

Waist Restraint Roll Bar Suspension Reflective Tape

15 [SolidEdge] – Center of Gravity

[SolidEdge] – Roll Bar

Drive System

Front Castor Wheels

Suspended Rear Wheels

Chain Lever System

Accessible Brakes, Gearing, Clutch

16[SolidEdge] – Full Wheelchair

Chain Lever System

Five Gears Available Parts Clutch to Reverse Chain Tensioner 0.79 to 2.45 Gear

Ratio

17[SolidEdge] – Chain Lever System

Clutch Assembly

Located Centrally Non-Standard

Clutch Easy to Assemble

18

[SolidEdge] – Clutch Assembly

Calculations – Gear Ratios

45.2368

900

mm

mm

r

r

w

a

79.034

1145.2

a

w

V

V

45.211

1145.2

a

w

V

V

19

2

1

n

n

r

r

V

V

w

a

a

w

Max Ratio

Min Ratio

Build Report Budget

Many off the Shelf Items

Standard Metal Sizes

Sponsorship Search Ongoing

SubTotal $1,877

Tax $263

Contingency (5%) $94

Total $2,234

Outside Donations $1,000

ME Departmental Donation

$1,000

Total $2,000

Net -$234

20

Schedule

Construction to Start After Exam Period Aluminum Welding in Question Testing by February 1 Completion by March 1

21

Conclusions

Design Requirements Met Design Essentially Completed Structural Materials Purchased Building and Testing March First

22

Special Thanks

Mechanical Engineering Faculty

Dr. Georgiades

Pam MacDougall

ME Class of 2007

23

Questions

24