Formula SAE

TM02's chassis was being designed alongside my components, but its geometry was driven by rule compliance and strength to weight optimization rather than component mounting. I had to fit the seat, firewall, and electrical hardware around the selected layout while meeting the requirements of the 2026 Formula Hybrid + Electric Handbook. Reconciling that layout with the interfaces to other components was the project's hardest design challenge.

The tractive system was the car's electrical propulsion system. Its status indicator (TSSI) communicated the electrical state, while the ready to move light (RTML) signaled that propulsion was enabled. I packaged both on a shared bracket near the top of the main roll hoop, locating the TSSI above the RTML and within 150 mm of the hoop's top to be rule compliant. This arrangement had to preserve visibility and helmet clearance while remaining inside the rollover protection envelope, the space protected by the roll hoops and bracing.

I designed this bracket as one bent sheet metal part so its profile could be cut on the waterjet. Four bends formed the flat sheet into a bracket with opposing indicator faces; I welded the finished bracket directly to the chassis. The sheet included bend reliefs where the bends terminated to limit tearing and distortion. I also accounted for bend allowance, the material needed to form each curved corner, so the finished bracket had the correct dimensions.

I designed the cockpit bracket around the shutdown and start buttons and two fault indicators, with the shutdown button positioned for a belted driver to reach at any steering angle. The indicators displayed faults detected by the accumulator management system (AMS), which monitored the traction battery, and the insulation monitoring device (IMD), which checked electrical isolation between the tractive system and chassis.

The car had separate master switches for its low voltage electronics and tractive system. I placed both on a shared plate to the right of the main roll hoop, the best location that satisfied the rules and accommodated the surrounding components. Height and external access requirements set the switch positions; I shaped the plate to connect that layout to the chassis. Each switch had a central clearance opening and two fastening holes, keeping the mounting interfaces in one flat part for straightforward waterjet cutting.

The rules required the side shutdown buttons, or big red buttons (BRBs), to be accessible from outside the car. I mounted them facing outward behind the driver at approximately head height. Each plate had a keyed switch cutout to fix the button orientation and an extended attachment area that connected it to the chassis.

Last year's simple metal seat accommodated all our drivers, but it was their main complaint: poor visibility forced them to crane their necks, compromising comfort and racing performance. Our drivers ranged from 5 feet to 6 feet 4 inches and varied in width, so the replacement had to accommodate different body proportions without repeating those compromises.

I used a PVC cockpit rig with a wooden backrest to measure driver seating positions, reach, and sightlines before fixing the seat contour. The seat angle also had to work beneath the main roll hoop, the protective structure behind the driver. The rules required at least 50.8 mm of helmet clearance from the hoop and bracing lines for every driver and a 95th percentile male template.

I recorded hip to foot distance, knee height and angle, and steering wheel position alongside a side view of the seated driver. The shaded region in the sketch estimates the forward blind spot, where the cockpit obstructs the driver's view of the road. Raising the driver could reduce this blind spot but consumed helmet clearance, while changing recline also changed reach and knee position. These dimensions had to be evaluated together, rather than choosing seat angle for comfort alone.

I translated the fitting measurements into a common seat contour, then fabricated a fiberglass shell over a 3D printed mold. Custom foam inserts for each driver, combined with an adjustable pedal box, accommodated the height differences without separate shells. Each seating position had to retain the required helmet clearance with the inserts fitted. This arrangement was intended to improve comfort and racing performance at this year's competition.

I mounted the seat on the two support crossmembers beneath the pan and behind the backrest, tying the chosen recline to both chassis supports. I also positioned openings for the 6 point harness to minimize interference with driver comfort.

The firewall separated the driver from the accumulator, the car's traction battery pack, and other tractive system components. I designed its outline, angles, and mounting locations around the chassis, with coverage determined by the tallest driver and the components behind it.

I cut the panel and mounting holes from sheet metal, then fitted it to the cockpit before sealing its perimeter against the sides and floor. The mounting interfaces had to preserve that continuous barrier.

I designed a shared flat backing plate for both rear brake lights near the car's rear centerline, between wheel centerline height and driver shoulder height. The plate fixed the lamps relative to each other and was cut from flat stock without the forming operations required by the status indicator bracket.

The ready to drive buzzer provided an audible warning when the car could respond to accelerator input. It came with a right angle bracket, which I welded directly to the chassis without an additional custom mount.

The printed duct connected the radiator at the larger rear opening to the fan at the smaller front opening. Foam end pieces and duct tape sealed the interfaces so air passed through the core rather than leaking around the test section.