Stair Caddy Carries items up to 50 lbs up and downstairs 2.009 Blue - PowerPoint PPT Presentation

Sketch Model Review Stair Caddy Carries items up to 50 lbs up and downstairs 2.009 Blue B

Stair Caddy Design For the 36+ million senior citizens

Existing Products AATA International SR 450 AATA International SR 1750

Comparison SR 450 SR 1750 Stair Caddy Mass of 49 kg 175 kg 25kg Cart Power 375 W 500 W 400 W Battery 3.5 hours 3.5 hours 5 hours Life Speed .15 m/s .05 m/s .31 m/s (7.9 in/s) (5.9 in/s) (12 in/s)

Testing for Consumer Needs n Safety - Slip n Not ruining floor material n Items not falling out n Items not squished n Storage

Other Issues Learned n Need more testing with treads n Turning Radius n Force applied to handle n Safety n Storage Size n Driving Downstairs

Appendices

Additional Calculations Total Steps 50 Steps Total Operation Time 50 sec Mass of Front Treads 3 kg Ang Speed .5 rad/sec (~30 deg/sec) Coefficient of Friction of Floor .3-.5 Motor Torque for Main Treads 20 Nm

Size Narrow Staircase 3 Contact Points Staircase 30 ” 30 ”

Stair Data n Building Codes (Public Areas) ¡ Tread length: 9 ” ¡ Riser: 8.25 ” n Measurements (Residential) ¡ Tread length: 7 ” ¡ Riser: 8 ”