Olin Electric Motorsports

Olin Electric Motorsports MK6 Car Drawing

Olin Electric Motorsports is a student-run team where we develop an electric racecar from the chassis up to compete in the Formula SAE Electric competition. I have been on the team for 3 years where I have taken on a variety of roles and projects. As the team's current mechanical design lead, I oversee the core development across the suspension, drivetrain, accumulator, and cockpit subteams of our latest car revision.

Eccentric Tensioner

The passive chain tensioner is a critical component in the car's drivetrain to ensure proper power delivery between the Emrax 228 motor and Drexler differential while eliminating shock loading in the chain. The tensioner relies on an eccentric bearing block to make fine adjustments to the distance between the differential and motor.

Olin Electric Motorsports MK6 Car Drivetrain Olin Electric Motorsports MK6 Car Drivetrain



I performed hand calculations to justify a bolt pattern that would meet the static loading requirements. I also checked that my design still had positive margins under the worst-case dynamic shock load arising from exsess chain slack. To gain insight into the strength of my part, I ran a structural simulation in Ansys Mechanical and used frictional contacts and pre-loaded bolts to produce a refined model of the mechanism interactions.



After reaching a design lock on the system, I machined the parts on a CNC mill. After removing the pedestal, I used a boring head on the mill to bring the bearing hole to its final dimension for a locational clearance fit with the bearing.

Chain tensioner being made on Tormach CNC machine

Fusible Links

Our MK-VI car runs on a custom 400-volt electric battery made up of 510 individual lithium-ion cells. The cells are connected with spot-welded nickel tabs which are carefully designed to melt at a certain fuse current. This safety measure is used to isolate a cell in the case of a thermal runaway scenario.

Nickel battery tab with integrated fusible links

I derived a 1st-principals thermal model to guide the design of the "fusible links". The model considers steady-state conduction, convection, and radiation to predict the temperature profile in the link for a given current. I then used a thermal FEA simulation to generate a compensation factor to account for complex geometric effects not accounted for in the analytical model.

Fusible link glowing red-hot duing a test FEA results showing fusible link temperature

The model was validated with experimental data where we measured the current required to melt a series of test-links. The data showed impressive agreement with the model across a range of link sizes and currents. In the future, this model will accelerate fusible-links design by automatically proposing a suitable link geometry for a given fuse current requirement.

FSAE accumulator assembly processes



Once the link design was finalized, I helped to create the manufacturing tools and processes for welding the battery segments. I designed a sheet-metal stamp to bend the nickel tabs into shape with accuracy and speed. I also made a multifunctional alignment jig to constrain the tabs during welding and provide insulation to the cells for added safety.

Nickel battery tabs cut using a water jet Nickel battery tabs spot-welded to cell terminals



Gokart Steering

I worked with another student to redesign the steering system on the electric go-kart test platform vehicle. I used Euler beam equations and FEA simulations to design a mounting bracket for the new rack and pinion system. I went on to fabricate the brackets and install the new steering system on the vehicle.



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