SAE MINI BAJA Front & Rear End Rear End: Jacob Ruiz Front End: Will Preston Lucas Cramer Jacob Grudynski Aaron King Jesse Summers Michael Edirmannasinghe Proudly Sponsored By:
Project Description • SAE Baja is a collegiate competition in which teams design, build, and test off- roading vehicles • Vehicles are presented in competition to a fictitious firm for possible manufacturing • Designs must abide by Baja SAE competition rules in order to compete • Must be able to perform well in Dynamic and Static events o Acceleration Test o Braking Test o Hillclimb o Endurance • Sponsors include W.L. Gore, NAU and SAE International Jesse Summers/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Black Box Model - Rear End Aaron King/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Detailed Decomposition Model (Rear End) Aaron King/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Black Box Model - Front End 5 Will Preston/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Detailed Decomposition Model (Front End) 6 Will Preston/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Concept Generation – Rear End Advantages: • Increases travel • Lower unsprung weight • Better ride quality • Independent suspension Figure 1: Tailing Arm with Links Disadvantages: • Long rear links • Hard to manufacture Figure 2: Tailing Arm with Links from Rear Jacob Ruiz/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Concept Generation (Double Wishbone) - Rear End Advantages: • Allows movement only in vertical direction to fix the toe Angle Disadvantages: • Requires a change to the frame • Heavy Figure 3: Double Wishbone Aaron King/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Concept Generation (Single Part Trailing Arm) - Rear End Advantages: • Lightweight • Easy Mounting • Durable Disadvantages: • Any failure leads to full system failure • Difficult hub/axle connections (manufacturing) Figure 4: Tailing Arm Single Part Figure 5: Tailing Arm Single Part Only Lucas Cramer/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Decision Matrix – Rear End Decision Matrix Single Piece Trailing Arm Trailing Arm Two Lateral Weight Double Wishbone CN's Links Score(1 -5) Weighted Score(1 -5) Weighted Score(1 -5) Weighted Safe 15% 5 0.75 2 0.3 4 0.6 Durable 15% 3 0.45 2 0.3 4 0.6 Lightweight 20% 1 0.2 5 1 3 0.6 Ease 10% 2 0.2 3 0.3 3 0.3 of Production Cost 15% 2 0.3 5 0.75 3 0.45 Performance 25% 4 1 3 0.75 5 1.25 Totals: 100% 2.9 3.4 3.8 Table 1: Decision Matrix (Rear End) Lucas Cramer/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Concept Generation – MacPherson Strut Advantages : - fewer number of parts Disadvantages : - not used for off-road platforms - not easily mounted to tube frames Figure 6: MacPherson Strut model [1] 11 Jesse Summers/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Concept Generation - Double Wishbone A Advantages : • Maintains desired alignment specifications Disadvantages : • Limited space between components, restricts maneuverability • Difficult to repair 12 Figure 7: Double Wishbone A Will Preston /10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Concept Generation – Double Wishbone B Advantages : • Consistent alignment • Allows space for steering, drivetrain components Disadvantages : • Requires high upper shock mounting point Figure 8: Double Wishbone B 13 SAE INTERNATIONAL Michael Edirmannasinghe/10-8-19/SAE Baja/F1908
Decision Matrix – Front End Table 2: Decision Matrix (Front End) Jesse Summers/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
CAD – Rear End Figure 8: Rear End Back View [2,3] Figure 9: Rear End Isometric View [2,3] Figure 10: Rear End without Tire [2,3] Jacob Ruiz/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
CAD – Front End • Rack and Pinion Steering System • Aluminum components. • Expecting Aluminum Steering Column. • Track Width • FE – 55 in • RE – 58 in • Wheelbase – 60 in • Ackermann angles • L – 48.72 degrees • R – 28.28 degrees Figure 11: Rack and Pinion Steering • Mounting angle • 24.62 degrees 16 SAE INTERNATIONAL Michael Edirmannasinghe/10-8-19/SAE Baja/F1908
CAD – Front End Figure 12: Front End CAD Isometric View Figure 13: Front End CAD Top View Figure 14: Front End CAD Hub Jake Grudynski/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
CAD – Front End 18 Figure 15: Front End CAD Jake Grudynski/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Bill of Materials – Rear End Ball Joint Rod Ends Tube Mounting tabs 5% 1% Table 3: Rear End Bill of Materials [3,4,5,6] Mounting Tabs Tires Qty Description Cost Total Cost 2% 13% Super-Swivel Ball Rear Hub 8 Joint Rod Ends $ 21.94 $175.52 Rim 9% 6% Rod Ends 1 Steel Sheet $ 47.53 $47.53 2% 1 Steel Bar Stock $ 57.94 $57.94 4 Polaris Rear Hub $ 75.99 $303.96 Trailing arm Tubing 10% 4 Steel Tubing $ 77.59 $310.36 2 Aluminum Rod $ 40.63 $81.26 Rear Links Fox Factory Series 3% 1 Float 3 Evol RC2 $ 1,595.00 $1,595.00 1/2" Ball Joint Rod 8 Ends $ 7.08 $56.64 Rear Shocks 2 Rim, Flat Black $ 92.80 $185.60 49% 2 Rear Tire $ 205.99 $411.98 Total $3,225.79 Figure 16: Rear End Budget Breakdown Jacob Ruiz/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Bill of Materials – Front End Table 4: Front End Bill of Materials 20 Michael Edirmannasinghe/10-8-19/SAE Baja/F1908 SAE INTERNATIONAL
Questions? SAE INTERNATIONAL
References [1]P. Czop, "Application of an Inverse Data-Driven Model for Reconstructing Wheel Movement Signals", Research Gate , 2019. [Online]. Available: https://www.researchgate.net/figure/A-schematic-view-of-a-McPherson-front-strut-suspension- system_fig1_273249518. [Accessed: 07- Oct- 2019]. [2]B. Koubaa, "Grabcad," 10 May 2012. [Online]. Available: https://grabcad.com/library/bicycle-shocks-burner-rcp. [Accessed 7 October 2019]. [3]McMaster-Carr. [Online]. Available: https://www.mcmaster.com. [Accessed 6 October 2019]. [4]A. Marketplace, "Polaris New OEM Bearing Ball Sealed," [Online]. Available: https://www.amazon.com. [Accessed 6 October 2019]. [5]Fox, "FACTORY SERIES FLOAT 3 EVOL RC2," [Online]. Available: https://www.ridefox.com/product.php?m=atv&t=shocks&p=1149&ref=family. [Accessed 6 October 2019]. [6]Partzilla. [Online]. Available: https://www.partzilla.com/product/polaris/1520263- 463?ref=d5473e3fd0ef85e6063d67b2d931889e5ebdedca. [Accessed 6 October 2019]. [7] Dixon, Suspension geometry and computation , 1st ed. Chichester: John Wiley, 2009. SAE INTERNATIONAL
SAE MINI BAJA FRAME & DRIVETRAIN Frame: Jacob Kelley Drivetrain: Tye Jorgenson Riley Karg Jacob Najmy Kaleb Brunmeier Proudly Sponsored By:
Project Description General: • Design and build a single-seat, all-terrain vehicle to compete in the SAE Baja Collegiate Competition • Entire vehicle built within the limits of the official rulebook • Performance measured by success in the static and dynamic events at competition in April Frame: • Cage designed and fabricated to withstand critical failure during normal operation, collision, or roll over • Interfaces with all other sub-teams • All welding done in-house Drivetrain: Figure 1: 2018-19 NAU Baja [1] • Responsible for transmitting engine power to vehicle propulsion • Up to 150 bonus points for operational 4WD/AWD system Tye Jorgenson SAE INTERNATIONAL
Black Box Model Weight of Driver and Drivetrain Withstand Applied Forces Forces From Suspension Hold Component Positions Frame and Drivetrain Throttle Position Forward Acceleration Electrical Input Noise and Heat SAE INTERNATIONAL Tye Jorgenson
Detailed Decomposition Model Forces Weight of Driver Withstand Applied Elastic and Drivetrain Forces Energy Convert Forces into Convert Potential Forces Potential Elastic Energy Elastic Energy into Opposing Forces Forces From Hold Component Suspension Positions Electrical Input Chemical Mechanical Condition Mechanical Convert Convert Chemical Energy Energy Force Mechanical Energy Mechanical Energy Release into Forward Energy into Throttle Position Force into Mechanical Energy Acceleration Useful Form Chemical Energy Release Losses Noise and Heat SAE INTERNATIONAL Tye Jorgenson
Drivetrain Concept Generation (ECVT) Generation Type: Gallery Method, Directed Search Generation Type: Gallery Method, C-sketch Figure 2: Spring 2019 Linear Design [1] Figure 3: Fall 2019 Design Iteration Advantages: Advantages: ✓ ✓ Lower initial cost User Input or automatic mode ✓ ✓ Robust Design Different modes based on terrain ✓ Disadvantages: Centralized Design (No moment on stepper motor) × Hard to Manufacture Disadvantages: × Large Moment on Stepper Motor Bracket × Battery reliant × Heavy Design with Solid Shafts × Possible stepper motor overheating SAE INTERNATIONAL Jacob Najmy
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