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

 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.

 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.

 Frame Design by Robert Goldmon

 Steering Design by Alfred Showers ‘Rack and Pinion Assembly’

 Schematic diagram of the A-arm suspension design using Inventor 2012 software.

 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 – in Max Compression in Range of Motion in ‘Shock absorber Values’ Stroke of 6.5 in Ext/Col  19.35/ (in.) 5/8 shaft MSRP $230

 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.

 Proposed suspension design

 An example of the A-arm design

 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

 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 5/14  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 components10/14  Perform cost analysis of new commercially available suspension design. 11/14