Baja SAE
Baja SAE
As the chief engineer of the 23XT, I am leading the top-level design of the entire vehicle, defining suspension hardpoints and overall architecture while balancing packaging, vehicle dynamics, manufacturability, serviceability, and the constraints of each subsystem. My role is to ensure that the frame, suspension, steering, drivetrain, brakes, and ergonomics are developed as parts of one integrated system rather than optimized independently, as well as tracking the design cycle of each component and providing input when needed to ensure overall vehicle sucess
I am also developing and maintaining several spreadsheet tools to improve the design workflow. For example, I reworked a 6 degree of freedom suspension loads solver for a new suspension geometry. This allowed applied wheel loads to be transformed through the suspension linkage and drive design of inboard components, such as the frame mount points and the rear gearbox case (due to our loaded rear axles). I also added several features to the drawing tree system that I developed last summer, allowing individual parts to have manufacturing operations tracked in a central location, as well as tracking the parts themselves and ensuring everything we need to build a car gets purchased and manufactured on time
For the JH22XT, I owned the suspension system from initial architecture through detailed design, analysis, manufacturing, and validation. I took in vehicle hardpoints and developed and optimized each part of the suspension. This required treating the suspension as an interconnected vehicle system rather than optimizing each component independently.
Within the larger system, I owned the complete design and analysis cycle for the control arms. Starting from the suspension hardpoints and available packaging space, I developed the control-arm architecture, created the welded assemblies in SOLIDWORKS, determined the governing load cases, performed hand calculations and FEA, and iterated the geometry to minimize mass while maintaining structural integrity. I also designed around real manufacturing constraints, including tube geometry, weld access, fixturing, tolerances, rod-end interfaces, and final assembly.
To develop realistic design loads, I collected wheel-force-transducer and strain-gauge data during vehicle testing, processed and filtered the results, and used them to establish a standardized set of suspension load cases.
I carried the resulting designs through release, fabrication support, assembly, and physical testing, using the results to validate both the individual components and the overall suspension architecture. The completed system experienced zero structural failures through more than 35 hours of testing and competition.
Control Arm FEA Example
Linear Potentiometer Calibration
Top Level Assembly CAD
Control Arms in welding jigs
In the summer of 2024, I designed the front upright for the JH21XT, Blue Jay Racing's vehicle for the season. This was an extremely fun challenge, because while I had to connect four points in space (the upper A, lower A, and tie rod mounting points and the wheel bearing location) to a high degree of accuracy, I had significant freedom in how I went about it.
Because of this freedom in form, I was able to design an upright in SOLIDWORKS and use Ansys to optimize it to be less than half the weight of the previous year's upright, all while making sure it didn't interfere with the rest of the front suspension, was able to take the loads applied to it by a Baja competition, and could be manufactured out of billet aluminum using a 5-axis CNC.
I also learned a lot about proper CAD practices and making the upright as parametric as possible during this design cycle, as whenever the suspension hardpoints were updated, the upright had to change. So, to minimize friction in these updates, almost everything critical on the upright is defined relative to the complex 3D sketch that is the suspension hardpoints.
FEA of one load case
In progress CAD
CAD in assembly context
Last year's upright
On last year's vehicle, the JH20XT, we expanded our custom data acquisition system significantly. One data point that we wanted to track closely to improve future cars was the torque applied to the drive axles. So, we decided that the best way to collect this data was to apply strain gages to the axles and measure it directly. However, this meant that we somehow had to get data off of a live, spinning axle.
To solve this problem, I designed a custom watertight enclosure to securely hold a custom PCB and battery and securely clamp to the axle. While these requirements seem simple, coming up with an enclosure that seals for hours at thousands of RPM was much harder than expected. For example, the plan from the beginning was the 3d print the enclosure, but when we submersion tested an FDM part, it leaked straight through the part, so the final version had to be SLA to eliminate this failure
I learned a lot about proper testing procedures during this project because of this. I went through several iterations to ensure that the enclosure would perform as needed, and that it would clear the suspension assembly as the drive axle rotated.
WSG box mounted to a front axle
Early CAD
The only box failure we saw
Clean interior after a day of competiton
In addition to wireless strain gauges, we also had linear potentiometers (linpots) on the 20XT. They were mounted between the frame and the upper control arm, and let us track the position of all four suspension linkages over the course of an entire competition, giving us more information on the state of the car and the loads it sees across the entire suspension, allowing future designs to be lighter and more optimized.
Because much of our data acquisition system is custom, we had to develop firmware and validate sensors ourselves. This rig that I designed and manufactured allowed us to develop this firmware off of the car, speeding up the development process and freeing up the car for maintenance or other testing.
The system was designed to closely mirror a suspension linkage. While it looks completely different, all the parts that matter for the sensor are there. It mounts one end of the sensor rigidly, and the other end to an arm with the same maximum and minimum angles as the linkage, making it look fairly similar to a full linkage to the linpot, while using significantly less material and greatly simplified construction methods.
Final CAD
Fishing for parts in the waterjet
Another type of sensor that we had on the 20XT were hall effect sensors that we used to measure speed. To accomplish this, we cut ridges into the outer profile of all of our brake rotors, then were able to use the frequency that they passed the sensor to directly measure speed of each of our four wheels and collect information on the state of our drivetrain over the course of a competition.
Similar to the linear potentiometer development rig, this allowed for firmware development off of the car. It uses a mock brake rotor with the exact same outer profile as the actual rotors, but with a different inner profile, allowing it to be spun with a shaft that can either be spun by hand or with a cordless drill instead of a full drive axle assembly. This simplified what was needed to test the sensors, making firmware development faster and cheaper.