SAE Mini Baja: Drivetrain By: Chris Gilson & Spencer Suggs Advisor: Ho-hoon Lee Instructor: Cris Koutsougeras ET493

What is Mini-baja? The SAE mini-baja is an international engineering challenge to design and build an off-road vehicle This vehicle will go through many stress tests: Acceleration Off-road terrain Steep incline Endurance

CVT Transmission & Differential Main components CVT Transmission & Differential Engine

Engine The engine is a Briggs & Stratton 10HP OHV Intek, Model 19 Cost: $250.00 We will need to work with the framing team to locate the position and design a mount to hold the engine in place with minimal movement

CVT Transmission The continuously variable transmission is an automatic transmission that can change seamlessly through a range of gear ratios Commonly used in ATV / off-road utility vehicles

Differential Options: (SRA) solid rear axle suspension (IRS) independent rear suspension SRA IRS

Solid rear axle (SRA) suspension PROS: Greater power transfer Better straight line performance Less chance of mechanical failure More cost efficient CONS: Less suspension travel Rougher ride quality Less ground clearance

SRA

Independent rear suspension (IRS) PROS: Greater suspension travel Better ride quality Greater cornering performance Higher ground clearance CONS: Less power transfer Higher cost Higher chance of mechanical failure

IRS

Deliverables Chris Gilson Spencer Suggs Both Design of engine mounting bracket Engine mounting bracket stress analysis Analysis of available gear ratios Power loss through the power-train Spencer Suggs Design of CVT mounting brackets CVT mounting bracket stress analysis Mounting bracket bolt analysis Mounting bracket bolt grade selection Both Ideal position of power-train Computation of the max torque of the wheels

timeline Week 1 – Week 2 Week 3 – Week 4 Week 5 – Week 6 Find the ideal position for the drive-train Week 3 – Week 4 Drive-train mounting bracket design Drive-train mounting bracket stress analysis Week 5 – Week 6 Mounting bracket bolt stress analysis Mounting bracket bolt grade selection Week 7 – Week 8 Analysis of available gear ratios Power loss through drive-train Week 9 Final Presentation

Going forwrd Begin to order parts needed Machine parts to spec Begin Assembly Test

References http://forum.longevity-inc.com/showthread.php?3371-SAE-Mini-BAJA-Project https://www.briggsandstratton.com/na/en_us/product-catalog/engines/racing-engines/model-20.html https://www.youtube.com/watch?v=uCEvBGT8twM