The Formula Society of Automotive Engineers challenges college teams nationwide to design, build, and drive single-person race cars. Mercer University is set to compete, however, their FSAE car lacks a pedal system. As part of my Senior design project, I undertook the task of fully designing and manufacturing an adjustable pedal system tailored to Mercer's FSAE car.
The design I created was a thread and carriage based design which has a threaded rod down the center attached to the main carriage. As the carriage is adjusted the threaded rod will rotate until the occupant releases the adjustment handle which will then lock the threaded rod in place. When completed all the subassemblies will be assembled then welded to the frame of the FSAE car.
The main structure uses four steel mounts that will be welded to the chassis of the car. These mounts hold up two steel connecting rods as well as two bearing housings which hold the central steel threaded rod
The carriage use a half inch aluminum plate with bearing mounts attached underneath to slide on the support rods. Underneath the plate the thread carriage is attached to the central threaded rod. This stops the carriage whenever the rod is locked. The gas pedal stopper and rubber bumper will be added on top to stop the pedal assembly from over rotating as well as supporting the throttle cable. Holes are drilled into the plate for mounting points as well as a spot to adjust the assembly with your foot.
The key lock is made up of two separate parts that are bolted together, since machining the part alone would be to complex. These two parts together house the spring loaded locking pin which will interlock with the connecting rod inside the assembly to lock the the rotation of the threaded rod.
The gas pedal is made up of the pedal arm, pedal axle, and the connecting brackets. The pedal itself is tensioned by a spring held down by two bolts. Additionally, the pedal has a connection point for the throttle cable at the back of the part. The brake pedal has already been purchased and will be mounted to the carriage assembly with bolts and locknuts.
During manufacturing this project, I spent around 70 hours working in the Mercer University machine shop for 10 weeks. During machining a few pieces needed to be redesigned due to not having the right tools on hand, however, once redesigned they fulfilled their intended purpose.
With only being allowed in the shop twice a week, the time allowed to manufacture this project was far less than I expected. To meet the deadline I had to scrap the gas pedal and wasn't able to weld the assembly together. For the future members of the FSAE team, I would recommend them to purchase a premanufactured gas pedal and mount it on the plate.
What I Learned
This project helped me to develop my CAD, manufacturing, and time management skills as well as understand the roles between designer and manufacturer. It also gave me more experience with shop machines such as bandsaws, mills, lathes, and CNC machining.