My Journey

Competing in Electric Vehicle this year all started back when I was a freshman. I went to the Science Olympiad interest meeting because, in my 8th-grade engineering and design class, I had built a solar-powered sun hat that could help workers stay cool while also charging batteries that could provide electricity in their homes in areas without reliable electricity. When I heard I could build things like that in the Science Olympiad, I was all in.

Even though most people were told to only do one building event, I had no interest in memorizing different types of trees or rock classifications, so I took on two—Air Trajectory and Scrambler. I had a partner for Air Trajectory, but I was solo for Scrambler, so I spent most of my time on it.

Scrambler is where you have to build a car that travels a distance between 7m and 10m and stops on a dot before the car crashes into a wall cracking the egg it's carrying and is powered by a falling mass—no electronics allowed. My propulsion system was decent; I watched a video and copied it as best as I could. But the car itself? A complete disaster. I had no power tools, didn’t understand the importance of exact measurements, and by the time I finished my first test, I had already put 20 hours into a car that was completely lopsided. Every piece was glued together five times over.

The one thing I was proud of was my wingnut braking system, which used a wingnut moving along the axle to stop the car when it hit a lock nut. But in my first test, my car immediately hit a wall, and my front wheel broke. While fixing it, I realized that three wheels would balance better than four, and I added washers to the back axle to even out the weight. After more testing (and breaking the car five more times), competition day arrived.

The night before, my egg contraption broke, and since I had already glued it so many times, nothing stuck anymore. I threw together a last-minute fix and prayed it would hold. Spoiler: It didn’t. On the way to the competition, I was literally holding the dowels in my hands, piling Gorilla Glue onto them. The guys running the event were cool (I’ve seen them at every competition since) and let me use a little extra tape to keep the egg from falling off.

First run? The hook didn’t unlatch—car didn’t move.
Second run? Car tipped over and moved an inch.

I was frustrated but determined. Immediately after failing, I went back, fixed the weight issue, and watched my car go the full distance. Even though my actual runs were terrible, I had followed every single rule to the letter, so I still placed higher than 50% of the competition. Despite the frustration, I couldn’t wait to do it again.

My sophomore year I stuck with Scrambler and Air Trajectory, but this time, I had no partners. The rules changed too—now they added a random sand bucket somewhere between the start and the finish, meaning I had to adjust my wheels’ angle on the spot to go around it. They also allowed a spring in the propulsion system, but the car still had to be powered by a falling mass. Obviously, I wanted to make the best design possible despite how complicated the build so I incorporated the spring.

But the competition was a month earlier, and I mismanaged my time horribly trying to juggle two events. This led to me pulling an all-nighter the night before the competition. I was camped out in my dad’s storage room, knees and back killing me, and I made the critical mistake of assuming my weight would always fall perfectly straight. It didn’t. I didn’t realize this until the night before the competition, and since it was 2 AM, Home Depot and Lowe’s were closed. Lesson learned: NEVER test the night before competition.

I spent the entire night trying to build something that worked like a PVC pipe to guide my weight, all while still finishing my other build. Nothing worked. At 4 AM, I had to completely redo my propulsion system to work like it had the year before.

Luckily, my car itself was way better this time, but it was too heavy because I had designed it with way more power in mind. I got to the competition running on adrenaline, barely thinking about anything except how I was going to set my wheels’ angle. The moment I read the rules about the random sand bucket, I got the idea to rig my axle through a sliding ruler so I could just move the slider to adjust the angle.

Somehow, everything ended up working—not amazingly, but well enough to get around the bucket—and I placed 5th. After that second run, the exhaustion hit me hard, but even through the frustration, the stress, the chronic pain, and the lack of sleep, I loved every second of it. That was the moment I knew I wanted to be a mechanical engineer.

It wasn’t about the placing or the medals—it was the process that I loved. I knew that next year, I’d come back stronger, dominate Scrambler, and finally make it to states.

When I looked at the events list for junior year, Scrambler was gone and it was replaced with Electric Vehicle. I knew it would be completely different, but I was excited.

This time, I had three building events—Helicopter, Electric Vehicle, and Wind Power. The only event I had a partner for was Wind Power. After barely surviving last year’s all-nighter, I knew I couldn’t afford to procrastinate, so I started immediately after varsity soccer ended in October.

I built my first version of my Helicopter over winter break, but I wasn’t satisfied and planned to make two more versions. Then junior year hit full force—four AP classes, ACT studying, and suddenly, my free time disappeared. By spring break, I had Helicopter 95% finished, but Electric Vehicle? I had barely started.

The only thing I had done was teach myself enough C++ from YouTube and online courses to code theArduino. I might have a problem with striving for perfection and never settling, but that meant I needed to fully plan my car before I built anything. I spent an entire Friday through Monday doing nothing but researching, problem-solving, and designing my build.

AP Physics helped a ton—especially since we had just covered rotational motion and torque. I had to figure out:

The size of the wheels
The weight of the car
The power from the motor
The type of motor

But during my planning I made a huge error that massively impacted my car. Starting on Wednesday I started to build and I stopped at 8 am the next morning, got 4 hours of sleep and started building again till 4am, got another 4 hours of sleep, and then built till the competition started pulling yet again all nighter before the competition. Smart? No. Luckily, the team made states so I am completely rebuilding the car based on what I learned. How do you not repeat the same mistakes and build the best car possible without using a kit? Look below

First Design - Materials and Design Explanation

When designing my electric vehicle, I carefully selected each component to optimize speed, control, and efficiency. The 1000KV brushless motor and 30A ESC provide the power needed to propel the car. Well actually too much giving the wheels a speed of 15000 RPM while the desired time which was to be able to travel 10 meters in under 3 seconds only required 980 RPM. In order to increase torque and maintain a controlled acceleration I used a 5 to 1 gear ratio with the 13T-48 pitch-3.175mm gear on the motor connected to the 62T-48 pitch-5mm gear on the rear axle. The rear wheels are 80mm, which not only increases torque but also ensures a smoother transfer of power to the ground due to having more contact area with the ground. In contrast, the front wheels are 65mm, designed to have more grip, which increases stopping power when the braking system is activated.

The M6 1mm pitch threaded rod was chosen specifically for the front axle because it allows the M6 wing nut to travel precisely as the car moves. As the wing nut moves along the rod, it eventually reaches a stopping point, applying pressure against a wooden dowel to bring the car to a complete stop. The axle is held in place using M6 lock nuts, M6 washers, and 6mm flanged ball bearings, ensuring smooth rotation while keeping the braking system functional and reliable.

For the rear axle, I used a 5mm stainless steel rod, supported by 5mm flanged ball bearings to reduce friction. The axle is secured with 8 shaft collars, preventing any unwanted movement while allowing the gear system to work efficiently. The carbon fiber plate serves as a lightweight yet strong base to mount all components, supported by ceiling beams which serve as a lightweight, yet sturdy structure for the chassis of the vehicle.

Powering the entire system is an 8x AA battery pack, which supplies 12V of power to ESC which then distributes 5V to the Aurdino, but 12V the motor. The electrical connections are made using jumper wires, keeping everything organized and functional. To properly mount the motor a small piece of wood is used.

Jumper Wires
1- M6 1mm Pitch Threaded Rod
1 - 5mm Stainless Steel Rods
6 - 5mm Flanged Ball Bearings
2 - 6mm Flanged Ball Bearings
1 - M6 Wing Nut
8 - M6 Lock Nuts
2 - M6 Washers
2 - M5 Washers
1 - Carbon Fiber Plate
2 - Ceilings beams
1 - Arduino Uno
1 - Arduino Uno Data Sync Cord
1 - 8x AA Battery Pack
2 - 80mm Wheels
2- 65mm Wheels
1000KV Brushless Motor and 30A ESC
62T-48 Pitch-5mm Gear
13T-48 Pitch-3.175mm Gear
8 - 5mm Bore Shaft Color
Wooden Dowel for Wingnut System
Wood To Mount Motor and Intermediate Shafts

First Design - Challenges and Solutions

The previous page outlined the final design I used for regionals. However, one major flaw in my build was that the 5:1 gear ratio only reduced the motor speed to 3,000 RPM instead of the ideal 980 RPM. The biggest challenge was finding the right gears to achieve this ratio. A 195T, 48-pitch gear with a 5mm bore simply wasn’t available on Amazon, and I didn’t have enough time to source a custom-made gear before competition day. My solution was to use two intermediate shafts, each with two gears, to achieve the correct reduction.

This was by far the most difficult part of the build, and unfortunately, I assumed that with all my planning that during assembly everything would work as planned while building which was finishing up the day before the competition all I had left was to assemble the gears and test (a horrible assumption). When I assembled the system, the intermediate gears didn’t mesh properly. The motor spun, but only three of the gears engaged, meaning the power transfer failed before reaching the rear axle. With just three hours left before competition, I had no choice but to rip out the intermediate shafts and directly connect the motor to the rear axle gear resulting in the 5 to 1 gear ratio. This last-minute fix completely changed the intended design.

Since the motor was flipped in the process, it powered the car in the wrong direction, causing me to have to flip the direction of the car meaning the car was now front wheel drive and had rear wheel breaking. The advantage of having larger rear wheels for increased torque and stability was lost. To make matters worse, the motor wasn’t securely attached due to time pressure, so it lacked proper friction against the gear. In a desperate attempt to fix this, I wedged a small block into the mount to force more contact.

With limited time and drying glue, I couldn’t test the final code properly. As a result, my car was too heavy, too slow, and lacked the efficiency needed to compete at states. The only part that worked as intended was the braking system, but unfortunately, a car that stops well doesn’t mean much if it never reaches the finish line in time. This experience, while frustrating, pushed me to refine my problem-solving process, and I knew that my next version had to be more precise, better planned, lighter and built with enough time for testing.

Second Design - Materials and Design Explanation

When redesigning my electric vehicle for competition, I knew I needed to focus on reducing weight, improving efficiency, and maximizing control while still ensuring the car could reach its target distance quickly and stop accurately. One of the biggest changes from my previous design was switching to a 3D-printed chassis made from eSun PLA. This material is not only lightweight but also strong enough to handle the stresses of the race while allowing for easy modifications. Also, with 3D-printed parts, the axles will be perfectly level, and the wheels will be perfectly in line with each other. Unlike my previous build, where excess weight slowed the car down and caused stability issues, the lighter chassis significantly reduces inertia, allowing for faster acceleration and more precise stopping.

A major area of improvement was the axle design. To minimize energy loss from friction, I incorporated a threaded rod modifier so a flat surface, like the steel rod on the back axle, will be in contact with the flanged ball bearings that are now 10mm to fit the flat circular modifier. In doing so, friction is significantly reduced compared to my last build, where the threaded rod was in contact with the flanged ball bearing. Less friction means less energy is lost from the system, and more of the motor’s power is transferred directly to the wheels instead of being wasted. Both axles and the wingnut system worked well in the last car, so I haven't made any adjustments to them.

To keep the axles secure, I used M5 bore shaft collars for the non-threaded axle and M6 lock nuts for the threaded axle. They are both small but essential components that prevent any unwanted shifting of the axles during motion. By firmly locking the axles in place, the shaft collars ensure that power from the motor is delivered smoothly, preventing misalignment that could lead to efficiency loss or instability.

For the wheels, I opted for four 65mm rubber tires. These wheels are the same wheels I used for the front (which ended up being the back) wheels in my first vehicle. They are far lighter than the back wheel in the original design and are a good size. I am prioritizing weight in this vehicle, so rather than getting some increased torque by differentiating the size in the front and back wheels, I am sticking with these wheels for both the front and back. Furthermore, the wheels provide good grip for fast stopping without skidding. I believe increasing the overall grip of the car, as well as reducing weight, will be crucial in increasing both speed and accuracy.

One of the biggest challenges in the design was determining the optimal gear ratio to balance speed and torque. After experimenting with different configurations, I decided to use a 70T steel spur gear on the rear axle paired with a 13T motor pinion gear. This setup provides a 5.38:1 gear reduction, meaning the motor’s high RPMs are stepped down to a more manageable speed while significantly increasing torque. By increasing torque, the top speed is lowered; however, this gear reduction perfectly balances the needed torque while still maintaining a high top speed. Also, the steel construction of the gears ensures durability, as plastic gears tend to wear down quickly under the high forces generated by the motor.

The Arduino Uno serves as the brain of the car, allowing for precise control over motor speed, braking, and data collection. To manage power delivery, I used a Mini Simple DC Brushless Motor Driver Board, which efficiently regulates the 1000KV brushless motor to ensure smooth acceleration without sudden jolts that could cause instability. Using a simple motor driver is crucial because, in my last design, I used a top-of-the-line ESC, which had tons of different safety requirements that caused the car to spend time calibrating each run. I was able to reprogram the ESC to disable the rest of the safety regulations, but using this simple motor driver will do the same thing to the motor without requiring a couple of seconds of motor calibration. The 1000KV motor is equally compatible with the motor driver so their is no need to change the motor for now.

Powering everything is an 8x AA battery pack, which provides a 12V supply for both the Arduino and the motor. Using Duracell AA batteries is the best option within the constraints of the rules, as they provide a consistent and stable voltage output for the longest duration compared to other allowable battery types. Maintaining high voltage throughout the run is crucial for ensuring maximum motor efficiency, as voltage drops can lead to slower acceleration and reduced performance. While speed and distance are important, adhering to competition regulations takes priority, making Duracell AA batteries the most reliable and rule-compliant choice for optimal performance.

A breadboard and jumper wires are used to wire the entire system together, allowing for quick modifications and troubleshooting without the need for permanent soldering. This flexibility was important as I continued refining the control logic and wiring layout.

To further improve control and performance, and with more time and a ton more familiarity with the event, I knew I could get a lot more complicated with this design and incorporated two key sensors: an accelerometer-gyroscope sensor and an encoder module. The accelerometer-gyroscope sensor helps track the car’s orientation and acceleration, providing real-time data that can be used to adjust speed, monitor handling, and detect any instability. The encoder module measures wheel rotations, ensuring that the car accurately calculates distance traveled. With this data, the Arduino can make precise adjustments to the motor output, helping to improve stopping accuracy and overall consistency. With the wingnut braking system, user control introduces potential human error. However, by combining the wingnut system—which stops both front wheels—with the encoder, which precisely halts the motor at the exact distance every time, the car should stop perfectly at the finish line without skidding while maintaining the highest possible speed throughout the run.

The entire system is activated with a simple on/off button, making it easy to start and reset before each run with the vertical pencil push required. This streamlined control ensures that everything is operational with minimal setup. By combining a lightweight chassis, low-friction axles, a powerful but controlled gear system, and real-time sensor feedback, I’ve significantly improved efficiency, precision, and reliability compared to my previous designs. As I test this car, I will be updating this website to follow the continued journey of my build and my solutions to the problems that might arise. I have provided a sketch of what the car will look like without the addition of the econder module or the accelerometer-gyroscope sensor.

2 - 10mm Flanged Ball Bearings
2 -M6 Threaded Rod Modifiers
1- M6 1 mm Pitch Threaded Rod
1 - M5 Solid Steel Rod
8 -M5 Bore Shaft Collar
2 -5mm Flanged Ball Bearings
1- 70T 48P Steel Spur Gear
1 -13T-48 Pitch-3.175mm Gear
M3 Threaded Screws and Hex Nuts
Jumper Wires and Breadboard
Arduino Uno
1 - 8x AA Battery Pack
Arduino Uno Data Sync Cord
4 - 65mm Rubber Wheels
Mini Simple DC Brushless Motor Driver Board
1- On and Off Button
eSun PLA
Accelerometer Gyroscope Sensor
Encoder Module
AA Duracell Batteries
1000KV Motor

Second Design - Challenges and Solutions

One of the biggest challenges I’ve faced is powering a brushless motor with AA batteries, which isn’t exactly recommended. Brushless motors pull a lot more current than alkaline AAs are really designed to provide, and in most cases, you’d expect major voltage sag or the batteries just not being able to keep up. But, interestingly enough, my previous car, which actually had an even heavier load, ran just fine on AAs, so I know it’s possible. All of the battery holders on Amazon use thin wires (usually 22–24 AWG), which adds even more resistance and limits the current flow. To work around this if necessary, I am looking at building my own battery pack using 18 AWG wire, which would reduce resistance and deliver power more efficiently. If the setup has connection issues or proves unreliable, I would 3D print a custom battery holder to keep everything solid and secure and incorporate it in 18 AWG. Another option I considered was switching to brushed motors, which would be way easier on the batteries since they draw less peak current—the brushed motor that would apply enough speed requires 5 amps, only one amp less than the batteries would provide compared to the brushless motor which requires 12 amps—but I ultimately ruled that out for now because brushed motors are heavier and less efficient, which would hurt performance more than it helps.

As for the ESC issue, I know I talked about how many ESCs have built-in soft start features in their safety regulations, which was a problem since I need instant throttle response. The fix? Ditching the ESC altogether and using a simple motor driver instead. Unlike ESCs, motor drivers don’t have all the built-in safety regulations like soft start, power ramping, or current limiting, which means as soon as I send a signal, the motor gets whatever power I need at that moment with no delays.

Then there’s the braking system, which is another thing that needs to be carefully planned. I’m going with a wing nut braking system, meaning I need a threaded rod for the braking mechanism and a non-threaded rod for the main drivetrain. This setup ensures the braking system is independent of the drive system, which is a huge benefit in terms of control and reliability. I also considered whether it would be worth achieving all-wheel braking using a timing belt and two timing pulleys, but that would add weight and make the design way more complicated, especially when it comes to figuring out how the gears would attach to the front axle. For now, that extra complexity just doesn’t seem worth it.

Another challenge was finding a way to allow the 6mm threaded rod to spin freely with minimal friction while maintaining a compact and lightweight design. The issue arose when I realized that standard 6mm ID ball bearings were not designed for threaded rods, as the threads would create unwanted friction and wear. I explored several potential solutions to address this problem. One option was to use a 6mm to 10mm sleeve adapter, which would fit over the threaded rod and create a smooth surface for the bearing. However, finding an off-the-shelf sleeve with the exact dimensions proved difficult, and custom machining a perfect fit would add unnecessary complexity. I eventually ran with the solution by finding an M6 threaded coupling nut as an adapter. This nut naturally fits onto the 6mm threaded rod, and if its outer diameter is close to 10mm, it will act as if it were a non-threaded rod rotating inside the 10mm flanged bearing. To optimize this setup, I considered minor modifications such as sanding the nut down slightly for a better fit, lubricating it to reduce friction, or even securing it inside the bearing with Loctite. This approach eliminated the need for complex adapters while ensuring a low-friction, stable rotation system.

Second Car - Results

Results from States Coming Soon - April 26th

Overall Suggestions

Coming soon after more testing.

Contact Information

When I first started researching for this event, I came across a website that was essentially similar to this one. It was created by someone who had previously competed in the competition, where he discussed his vehicle and the series of designs he went through. He provided his LinkedIn, and, of course, I recognize that he now has a job at Tesla and is very busy. Still, I reached out, hoping for some advice, but I never received a response. In the spirit of my passion for Science Olympiad and this event—as well as knowing how helpful specific advice would have been—I am providing my email and promise to answer every single question sent to me to the best of my ability.

Email - lucasjacobs711@gmail.com