HUMAN POWERED TRACTOR Team Members: Ethan Harris: Team Leader/Design Engineer Matthew Burtis: Team Reporter/Design Engineer Brandon Roberts: Design Engineer Charles Ogden: Design Engineer Sponsor: Mr. Morton Advisor: Dr. Erikson

Safe and effective Payloads up to 1000lbs Human powered Third world countries Street vendors Dangerous environments Purpose

Economics

1. Steel Tube Frame 2. Articulated Steering 3. Rotary Crank input 4. Planetary Ball CVT 5. Transaxle 6. Hydraulic disc brakes 7. Adjustable Seating Overall Design

Payload of 1000 pounds Reverse Lock wheels on asphalt 19 foot turning radius 0.17 horsepower per person steady state input Climb up to 7 percent grades Design Specifications

Design Considerations Human input Articulated steering Two handed input Calculations Input forces Component sizes Steering Solution Dual lever input Combining gear box Adjustable tie rod Articulated via hitch

Design Considerations Hydraulic disc brakes Wheel lock up 2000 pound vehicle weight Calculations Human input Line pressure Brake force Cylinder sizes Brake Design Solution inch bore master cylinder Lateral movement of steering arm 2000 Ford Taurus parts

Results of test Lock up attained Moderate brake heat Empty trailer tipping Causes of tipping Excessive front end weight Solutions Reposition of Center of Gravity Trailer (rear) brakes Brake Testing

Drivetrain Design Design Considerations Human Input Speed ratio range Power combination Final output Calculations Input power Torque required Component sizes Solution Bicycle crank input Planetary ball CVT Jackshaft Final transaxle

Design Considerations Reverse Speed ratio reduction Differential Calculations Shaft torques Baseline gear calculations Bearing loads Transaxle Design Solution Oil bath transaxle Reversing gear set 3:1 speed ratio reduction

Results of test Failure of gear teeth Cause Movement in system Proposed Solutions Mount carrier to case bearing Upgrade case bearing Investigate increased gear size Transaxle Testing

Temporary solution Chain set Forward only operation #40 Roller Chain 2.4:1 reduction Allowed operation Transaxle Modification

Optimize transaxle Reposition COG Improved ergonomics Wider gear ratio Lighter construction Additional implements Future Improvements

Thank You!