For the 2023 FSAE Competition I optimized and manufactured custom drive axles for our MK 8 vehicle, which achieved 10th place out of 120 other collegiate teams!!! The axles we had previously been using were purchased and designed to withstand a load of 1200 ft*lbs, which was well above the theoretical torque we had calculated and applied factor of safety. While this had not been an issue in the past, as we continue to strive to improve the performance of our vehicle it was clear that this component could produce significant results if optimized correctly. By reducing the mass and Moment of Inertia (MoI) of our drive axles, we can increase the acceleration of our vehicle by reducing the MoI of the system transfer the power from the engine to the wheels, thus more of the engine's torque will go into rotating the wheels than the system itself. 

In order to properly redesign the axles, my team and I used strain gauges to accurately measure the strain within the axles we were currently using. This allowed us to calculate the torque load being applied to the wall of the shafts. I then created a MATLAB script to iterate through different materials, outter diameters, and inner diameters to find the most optimal combination for the load case we had verified. After having considered several material and dimensions, we decided to use 300M steel with a 0.6" ID and 0.795" OD. This gave us a 29% decrease in the weight of each axle, a 20% decrease in the axles' MoI, and a 0.22% increase in acceleration, all while still achieving a Factor of Safety of 1.5.

After finalizing the design of the axle I was able to move on to manufacturing. The most difficult portions of manufacturing would be creating the spline sections, drilling the interior hole through the whole shaft, and heat treating the completed axles. I contacted several dozen manufacturers over the course of a few weeks, eventually finding enough for all three processes (Gear Hobbing: Gerhardt Gear, Gun Drilling: Gun Drilling Specialties, and Heat Treating: Continental Heat Treating). All of which I was able to get sponsored, allowing us to reduce the cost of the shafts by 40%.