Formula 1: Formula 1 Group Members: Quinn Collett Steve Godlewski Tobiah Halter Jeff Swanson Academic Advisor: Dr. Chien Wern June 4, 2003


Introduction: Introduction Formula SAE is a competition focused on the design and fabrication of an affordable, weekend racecar. Performance and reliability are necessary attributes. As a Senior Project group we chose to design three major components of the car.


Project Scope: Project Scope Design, fabrication and testing of the three design components: Hub Assemblies Drivetrain Aerodynamics


Decision Process: Decision Process Product Design Specifications External Search Internal Search Concept Evaluation


Presentation Outline: Presentation Outline Rear Hub and Upright Design Front Hub and Upright Design Differential Housing and Drivetrain Design Aerodynamics Design


Rear Hub and Upright Design: Rear Hub and Upright Design


Components: Components Bearing Housing Flanges Connection Points Angle Bracket Bearings Fasteners


Analysis of Hub: Analysis of Hub Material: 6061-T6 Aluminum Yield Strength: 40 ksi Factor of Safety: 3 Design Stress: 13.3 ksi Results of FEA Analysis: Max Von Mises Stress: 14.5 ksi Maximum Displacement: 0.002 in


Analysis of Upright: Analysis of Upright Material: 6061-T6 Aluminum Yield Strength: 40 ksi Factor of Safety: 3 Design Stress: 13.3 ksi Results of FEA Analysis Max stress: 16.3 ksi Max Deflection: 0.004 in


Verification: Verification PDS Criteria Weight: The hub assembly will weigh less than 17 lbs. Hub=2.5 lb, Upright=4.5 lb, Total = 7 lb Size/shape: Components will fit within an 13 inch wheel. It does fit. Maintenance: 2 hour yearly overhaul Maintenance free: sealed bearings, locktite on all screws Installation: Install in less than 120 min. Can be done inside of an hour: press in bearings, 3 bolts per side Cost (materials, bearings, bolts): less than $400 Housing: $54.00, Hub: $186.94, Flange: $65.20, Connectors: $50.54, Angles: $1.34, Fasteners: $8.61, Bearings: $18.80 Total Cost of Materials: $385.43 Dynamic Testing Has performed properly to this point


Front Hub/Upright: Front Hub/Upright Design Criteria PDS 30%-40% weight reduction over last years car Ideal weight of 14 lbs. Assembly fit within a 13 in. dia. Wheel Handle loadings in race conditions Incorporate connecting points for suspension and steering systems Component Selection Suspension Geometry Steering Positioning Brake Components Bearing Selection


Front Hub/Upright: Front Hub/Upright Analysis Calculations Track Conditions Top speeds 60 mph/ Avg. Speed 30 mph Safety Factors


Front Hub/Upright: Front Hub/Upright


Front Hub/Upright: Front Hub/Upright Materials 6061-T6 Aluminum 304 Stainless Steel Manufacturing CNC Mill Lathe Press


Front Hub/Upright: Front Hub/Upright Verification Weight Last years 32 lbs. This year 11.4 lbs. 64% weight reduction Under Ideal weight of 14 lbs. Track testing Handles loads under acceleration, deceleration, and cornering Problems/Improvements Two Piece Separation Spacers Further Advanced Optimization Weight reduction Cost reduction


Drivetrain: Drivetrain Use of Common Parts Honda CBR 600 F1 Limited Slip Differential Use of Common Materials 4140 Steel 6061-T6 Aluminum


Rear Differential: Rear Differential Aluminum Housing Zexel Torsen Limited Slip Differential Sealed Bearings Retain Gear Oil Check Valve Roll-Over and Tilt Protection


Power Transmission : Power Transmission Axle Shafts 4140-3/4” Steel U-Joints Drive Shaft Splined Drive Chain and Sprocket Rear Mono-Brake


Drive Train Verification: Drive Train Verification Performance Dyno-Testinig Road Testing Weight Target 50 lbs Manufacturing Time Target 15 hours Production Cost Target $2000 Failures Drive Axle Welds Shielded Bearings Changes?


Acceleration Torsion Testing: Acceleration Torsion Testing


Aerodynamics & Body: Aerodynamics & Body Modeled using 3-D software package, SOLIDWORKS® Forms CNC machined Allowed for precision forming and exact fit Material: 1/8” fiberglass mat w/ fine mat finish Light weight and durable Total Weight: 8.5 lbs. Significantly below PDS target


Body & Aerodynamics con’t…: Body & Aerodynamics con’t… Estimated drag coefficient (CD), front lift coefficient (CL), drag force (D) and lift force (L) CD = 0.14 D = 1.950 lbf CL = 0.15 L = 0.910 lbf © 1992 SAE


Body & Aerodynamics con’t…: Body & Aerodynamics con’t… Estimated skin drag coefficient (CF) and surface shear force per unit surface area (τ) (friction resistance) CF = 4000 τ = 901.87 lbf/ft2 Source: Race Car Engineering, Katz


Body & Aerodynamics con’t…: Body & Aerodynamics con’t… Overall Performance Evaluation Overall weight of car significantly minimized PDS projected weight = 30 lb Actual weight = 8.5 lb Dimensions of car w/in 2% of desired Drag force minimized as specified in PDS Typical F-1 CD = 1.07 PSU Formula CD = 0.015 Lift force acceptable but could be further minimized by introducing further down force components which were sacrificed to make room for critical components (i.e. intake apparatus, radiator) Typical F-1 CL = -0.99 PSU Formula CL = 0.015 Cooling performance maximized by channeling air over water-cooled components average engine temperature w/o channeled air over radiator = 220°F average engine temperature w/ channeled air over radiator = 200°F


Performance in Action: Performance in Action