Science Olympiad
I have been competing in Science Olympiad for the past seven years, in a mix of engineering design events. My journey started in sixth grade at Winston Churchill Middle School, and over the years, I have developed valuable skills in manufacturing, physics, and more. Currently, I am a member of the Mira Loma Science Olympiad team, and coach Flight and Roller coaster for Winston Churchill Middle School. This page highlights some of my favorite build events.
Wright Stuff is the culmination of my work with model aeronautics. Using a wound rubber motor, the propeller enables it to take flight. Beyond just balancing the center of gravity, there were a number of factors that I had to carefully adjust to ensure that the plane performed at its maximum capacity. Because I planned to fly indoors, I had to structure my plane so that it would climb very slowly in a circular path, take a few laps close to the ceiling, and come down in a very slow descent. To achieve this flight behavior, I had to warp the surface of the wing by 2 degrees using a carbon fiber spar (tuned through too many hours of flying). This incorporated a curve that would result in more drag on the left half of the plane, enabling a counterclockwise turn. I also designed an adjustable wooden post mount for the wing so that I could adjust the angle of incidence of the plane as I tested. This allowed me to adjust the climb and fall rate until it was perfect
Flight
The Science Olympiad Elastic Launched Glider was my first exposure to model aeronautics. It took a while to find my footing in gliders: I spent over half a year failing to make the plane glide for more than a few seconds. It seemed like each time I shot my plane into the air, it failed to catch air and fell down just as fast. I knew that I couldn’t simply rely on the design from the kit. To help my plane catch air, I used foam flaps that would blow back during the high speed vertical launch, but would then pop down and cause drag for the plane, inducing stable flight. In order to prevent the fuselage from snapping, I reinforced it using carbon fiber tow. To trim the weight of the plane further, I cut out the center of the wooden wing and replaced it with a foam filler piece. This reduced weight, without compromising performance. By venturing into model aeronautics, I was able to gain a better understanding of aerodynamics and how to balance center of gravity for optimal performance.
The model helicopter pictured right is eight grams, and can fly for 2 minutes and 30 seconds. I designed it to fly straight upwards, balancing itself against the ceiling through the rotating contact disk. The upper and lower propellers are linked with a wound rubber motor to store energy and move the propellers. Why the different number of blades between the upper and lower propellers? Well, I experimented with a variety of blade counts, and implemented a 4-2 combination for balance. With the upper propeller generating more lift, the lower end of the helicopter would in effect behave as if it had more mass, creating a stabilization effect similar to that of a pendulum. To optimize the energy storage capacity of the motor, I explored rubber elasticity and hysteresis properties, and determined the optimal winds and thickness for the propellor. To brace the tension of the motor, I used kevlar thread in a truss formation to prevent the motor stick from bending on itself and snapping.
Mission Possible
My Science Olympiad Mission Possible is a Rube-Goldberg machine consisting of 27 tasks. Using various energy transfer reactions, the Mission can run from anywhere from 30 seconds to 2 minutes, adjusted by the sand and pendulum clocks incorporated into the device. Due to the connected nature of Mission, its consistency was incredibly hard to tune, especially due to the large numbers of “energy jumps” (tasks where a very light trigger released a disproportionately large amount of stored energy). To prevent tasks from activating out of sync, it was necessary to construct balanced transfers that would only trigger when they were supposed to. The capstone of the mission is definitely the tee deposit system, in which the golf ball that was initially dropped in to kickstart the pendulum rolls down the ramp, knocks the steel ball bearing off, and lands on the tee, with the entire ramp the ball traveled on then retracting to clear a 20 cm radius around the ball.
My device was designed to be as modular as possible. This was for two main reasons: firstly, I would need to be transporting my mission across the country for competitions, meaning that it needed to fare well on the plane. If I could decompose it into specific components, I could package and ship it easier. The second reason was tied to the theme of consistency that is the backbone of my build: by having modular connections, each task could be removed and debugged, easily rearranged for a more optimal order. Moreover, this gave me the opportunity to standardize energy triggers between tasks. Since the Inclined Plane, Pulley, Wheel & Axle, and Tee deposit all trigger in the same way, refining the transferring mechanism benefits all of the tasks. To manufacture most parts, I mixed wood and plastic building pieces to create each assembly, and learnt 3D printing to create more precise components.
Wifi Lab
My Wifi Lab Antenna was my chance to get back at the horrible Wifi in my room by building its replacement. Unlike the isotropic monopole typically used for Wifi, I focused on a more directive design for a focused signal. I built my antenna based on the design of a disk Yagi-Uda antenna, using a copper coated driven element connected to an SMA source, with three directors and a reflector to minimize the side and rear lobe levels. However, my handcrafted disks were not yet precise enough.To ensure that my spacings gave the optimal Front Lobe Level, I used my 3D printer, and I used a CNC machine to fabricate thick aluminum and copper disks that precisely matched the necessary impedance profile that I calculated. I also used glue instead of solder to make the electrical connection to reduce unwanted capacitive effects between the driven element and the directors. Through careful design, my antenna had a working range (dBm > 70) over 3x that of a typical home antenna.
It’s About Time
My Science Olympiad It’s About Time build is a timekeeping device designed to sound a signal three times with intervals between 10 to 90s with a precision of 0.05s. In developing the timekeeping mechanism, I struggled with a variety of escapement designs, from lever to deadbeat to anchor. However, they were inconsistent and unsustainable. After I switched to a spring-based swiss lever escapement, I studied models online before starting my own design. After months of calibration of the 3D printed rebound spring and its inertial damper–adjusting elasticity and mass through infill, thickness, and filament–until it worked perfectly with my pallet fork for smooth timekeeping. To sound the signal, I used a carriage rotating with a velocity set by the escapement. Over time, the lever on the carriage would encounter a peg, and would strike the bell after it passed below. By adjusting the position of the three pegs along the rail, I was able to adjust the time to a precision of 0.05s.