SAE MINI BAJA PROJECT Suspension Design Analysis Engineering

SAE MINI BAJA PROJECT Suspension Design Analysis Engineering Technology 493 Mechanical Concentration Instructor: Dr. Koutsougeras Advisor: Dr. Ho-Hoon Lee Senior design project By: Ryan Schech Spring 2014

SAE MINI BAJA COMPETITION � Baja SAE® consists of competitions that simulate real-world engineering design projects and their related challenges. Engineering students are tasked to design and build an off-road vehicle that will survive the severe punishment of rough terrain.

OBJECTIVES � My objectives for this project is to study and analyze the methodologies taken, by former students, in the designing of the front suspension, frame, and steering designs. � I will need to modify the front chassis and suspension designs in order for commercially available parts to work on the mini baja.

CONSTRAINTS TO CONSIDER Ø Frame Design by Robert Goldmon

CONSTRAINTS TO CONSIDER � Steering Design by Alfred Showers ‘Rack and Pinion Assembly’

SUSPENSION DESIGN � Schematic diagram of the A-arm suspension design using Inventor 2012 software.

SUSPENSION DESIGN � From the calculations derived, a suitable option for the front shock assembly is one produced by Fox Racing, the ‘Emulsion 2. 0’ shock absorber. ‘Optimal Values’ • Static Ride Height – 16. 430 in • Max Compression -- 13. 550 in • Range of Motion -- 2. 88 in ‘Shock absorber Values’ • Stroke of 6. 5 in • Ext/Col 19. 35/12. 580 (in. ) • 5/8 shaft • MSRP $230

SUSPENSION DESIGN � Selection of the coil over spring will be one objective. Based on the proposed design calculations, ideally I need a spring rate of about 73 lbs/in. This is not a commonly produced spring and would cost too much to purchase a custom spring. I need to modify the design of the front chassis so that the design will work with a commercially available spring rate.

SUSPENSION DESIGN � Proposed suspension design

SUSPENSION DESIGN ØAn example of the A-arm design

DELIVERABLES � � Theoretical Part (spring semester) � Research � The methodologies used in designing the front suspension, frame, and steering system by former students. � Using differential equations to achieve a comfortable ride at a frequency around 1 Hertz. Application Part (fall semester) � Find what spring rates are commercially available � Adjust the front chassis design to allocate for the obtainable spring rate. � Form an equation to represent the relationship between the change in angles and lengths of the front chassis design. � Write a program in C that uses this relationship to determine the values of the variables that form the chassis design. � Construct a prototype of front chassis to test the results � Perform a cost analysis for the suspension

TIMELINE � Project selection and approval 3/14 � Perform the ideal calculations 4/14 � Compare results to what is commercially available 4/14 � Provide a research report on the design methodologies � Adjust the design to suit the available spring rate. 6/14 � Form an equation representing the relationship between the variables that describe the front chassis and suspension design. 8/14 � Construct a program in C that determines the variables 9/14 � Obtain the appropriate suspension components 10/14 5/14

QUESTIONS?