CatMobile Front Suspension
Daymon Fritz
Abstract
The Central Washington University (CWU) Mechanical Engineering Technology (MET) program owns an electric vehicle called the “Cat-Mobile” designed to be entered into an Electrothon America race. The Cat-Mobile is a collaborative project, various aspects of which are built by CWU MET students in the capstone sequence of the senior year. For the Cat-Mobile to operate safely and effectively, it was necessary to design and build a proper front suspension system. The suspension needed to meet Electrothon America Handbook rules dictating a minimum ground clearance of 2” and optimize material usage to keep added weight at or below 20lbs. Loading and stress analysis was used to design the suspension system, and FEA analysis assisted with optimization. The final design modeled a typical “double-wishbone” or “double A-arm” style suspension. A spindle assembly was mounted between the A-arms with the use of ball-joints. The spindles included provisions for steering, and potential mounting locations for braking components. A coil-over style shock absorber is used which can allow for height and dampening adjustments. The total mass of parts added to the Cat-Mobile was just 12.7 lbs. The ground clearance of the Cat-Mobile can be adjusted and at minimum height adjustment, conforms to the Electrothon America requirement of 2”.
Keywords: EV, Electric Vehicle, Electrothon America, Suspension