ME 489 Formal Design Review

September 22nd, 2004

Garrett DavisMatt MoodyArnar Thors

Background Info

• The Great Moonbuggy Race– NASA/Marshall Space Flight Center– US Space & Rocket Center– University of Alabama

• High School Student Customers– Vinemont High School

What is GMR?

• Human-powered

• 2 passengers – female & male

• Must collapse into 4’x4’x4’ volume

• 15” from ground

• 20 ft vehicle carry

• 20 ft turning radius

Customers

• Vinemont High School• 15 high school

physics students

• Political Implications– UA Recruitment– Vinemont HS Involvement– NASA Awareness

Customer Req’ts

• Adjustable Seat• Suspension/Stability• Lightweight• Rear Steer/Front

Drive• Comfortable Seats• Colorful• Single-gear drive

• One-Steer/One-Brake• Steering Wheel Type

(Primary)• Tires – Hoss-Daddy

Side-by-Side Seating

Concept #1

• Front/Rear WB• Cam-style Steering• Rear Drive/Derailleur • Triangle cross-section

frame

Concept #2

• Front WB/Rear Swingarm• Cable/Pulley Style Steering• Rear Drive/CVT Gearing • Square cross section frame

Concept #3

• Front Swingarm/Rear WB• Rear Rack & Pinion Steering• Front Drive/Derailleur w/ rev• I-Beam, T-shape frame

Concept Evaluation

Criteria Weighting Concept #1 Concept #2 Concept #3

Weight 20% 0.4 0.2 0.6

Safety 20% 0.2 0.2 0.5

Manufacturability 15% 0.23 0.23 0.45

Ergonomics/Comfort 5% 0.15 0.1 0.05

Size 10% 0.1 0.25 0.25

Simplicity 10% 0.1 0.25 0.25

Maneuverability 10% 0.2 0.1 0.3

Gearing 10% 0.3 0.2 0.1

Total 100% 1.98 1.53 2.5

Concept #3

Concept #3 Development

• Concept deviations– Change of frame cross-section– Derailleurs ditched for single speed– Reverse undecided– Independent swingarms changed to solid

• Further Development– All aluminum frame/suspension comp.– Adjustable seating position refined– Main frame structure reinforced

Concept #3 Development

• Major Areas of Concern:– Main Frame Member– Swingarm– Front Axle Sizing– Sustainability (common replacement parts,

fatigue analysis)– Shock/Spring Choice– A-Arm Geometry/Size– Balance/CG (ride height/weight distribution)– Cost Effective Material/Parts Choice– Cost Effective Fabrication Techniques

Future Plans8/29/04 9/5/04 9/12/04 9/19/04 9/26/04 10/3/04 10/10/04 10/17/04 10/24/04 10/31/04 11/7/04

Planning Meeting

Team Organization

Concept Generation

Customer Meeting

Concept Evaluation

Design Development

Formal Design Review

Parts Gathering

Design Review #1

Construction

Design Review #2

In-House Testing

Customer Testing

Final Adjustments (Repairs)

Design Review #3

Final Presentation

Future Plans

• Construction– Group-Wide Limitations– Intentions to Build Separate from UA

Engineering Machine Shop• Student Projects Building• Access to Shelton State facilities• Access to privately owned businesses/shops

– Individual Construction Schedule

Future Plans

• Procured Parts Listing:– Major Aluminum Frame Members– Minor Suspension Members– Tires/Wheels– Rack-n-Pinion – Steering Column & Wheel– Brake Caliper– Steering Linkages– Shock/Spring Selections– Seat Material

Conclusion

• Questions?