What I Contributed:

I worked with a machine shop to build the enclosure, using my drawings for custom cutouts. I designed a light fixture with a built-in fan in SolidWorks and cut aluminum parts with a waterjet, which were then spray painted black. Soldered all the ESC, fan, and LED connections to keep things waterproof and worked with a breadboard to connect all the electrical components. I 3D-printed mounts for the breadboard and enclosures for the motor, shaft coupler, and bushings to hold the rotating shaft. Since no propeller fit, I waterjet aluminum, which I bent and sharpened to make rotors. Lastly, I laser-cut Delrin parts to finish the enclosure, making everything come together smoothly.

Build Requirements:

• We aimed to keep costs low by minimizing the purchase of new parts, but we still wanted a polished look to give the lab a clear sense of the final design. 

• The setup required five motors, an LED light, and a fan to cool the LED. The motors needed a burst mode to "blend" the kelp into finer particles, with each motor controlled by a separate button for burst activation. 

• To ensure durability, we focused on making the enclosure as watertight as possible, keeping all electronics safely enclosed since this would operate in a wet, refrigerated environment. Any metal used needed to be rust-resistant to prevent corrosion over time.

Challenges Encountered and Solutions Implemented:

• The rotors initially hit the glass test tubes, causing the electrical system to brown out. While the 3D prints already included a bushing, I found that adding a second one gave the rotors extra stability, allowing them to spin more smoothly and straight. 

• During testing with three motors, each motor spun at a different speed despite receiving the same PWM signal from the same microcontroller. We discovered this was due to the ESCs being overly customizable; they didn’t come pre-configured with a PWM range, so each ESC had slight signal variations, affecting motor speed. To fix this, we chose a single speed that all motors could reliably achieve and built a linear model to set a consistent PWM range in each ESC, standardizing their output speeds.

• Additionally, the plastic rotors we used had a high angle of attack and didn’t fit well in the test tubes. Since suitable small rotors weren’t available, I created a basic rotor design, cut it with a waterjet, sharpened it, and attached it to the shaft. Although these rotors weren’t aerodynamically optimized, they effectively served the purpose.

Lessons Learned:

• Asking questions to more experienced engineers has been really helpful—they understand things I’m still figuring out and can steer me in the right direction. 

• I also need to work on clearly explaining the issues I encounter. Sometimes I have trouble finding the right words, which can lead to confusion. If I can’t communicate my ideas effectively. Even the most interesting design won’t make much impact if no one fully understands it.

What I Contributed:

I used a laser cutter to create motor patterns on the Kelp Kube lids and collaborated on designing a motor attachment that locks to a PVC pipe. I improved the initial design by replacing o-rings (which require specific tolerancing) with a more compatible clip system to accommodate varying PVC dimensions. I soldered electrical enclosures and collaborated with the machine shop to cut rods to specific lengths and modify enclosures. I programmed in CircuitPython to control motor speed at 7 cm/s, translating speed to PWM frequency. I chose compatible electrical components which I wired and coded per spec sheet requirements. A soldering lesson with Brian Kelly enhanced my soldering skills, including Molex connections. I utilized MarkForged Mark 2.0 3D printers to produce the motor attachments. For the air interface, I employed a WaterJet to fabricate custom rubber gaskets, ensuring secure sealing for consistent air flow control. 

Build Requirements:

• All components within the Kelp Kube needed to be made of plastic or rust-resistant metal to prevent corrosion.

• The system was intended for use in a high-moisture environment, so the electronics had to be shielded to protect against accidental splashes.

• The motor casing/air tube needed to be removable in case a specific experiment did not require a motor/aeration.

Challenges Encountered and Solutions Implemented:

• Kelp requires saltwater to grow. However, aerating saltwater leads to salt formation, which caused problems as salt accumulated on the motor, prompting us to put standoffs to allow more airflow between the motor and Kelp Kube, and also to make the hole in the top of the Kelp Kube smaller to allow for less salty air to come out. 

• The electronics box we initially purchased was slightly too small for the components we needed: a microcontroller, a voltage step-down, and a stepper controller. We had to rearrange the components to make everything fit.

• The aeration plate at the bottom presented issues because each Kelp Kube had slight size variations. We initially planned to laser cut the plates to reduce costs, but each plate didn’t fit each Kelp Kube consistently. Ultimately, we opted to 3D print the plates with a rubber gasket, allowing them to fit different Kelp Kubes.

• The aeration plate also posed challenges because it was difficult to keep it completely flat. If it wasn’t level, bubbles only emerged from one side. To solve this, we placed the bubble holes around the middle to achieve more even distribution.

Lessons Learned:

• Design first, build second. If we had measured the electronics first and then selected a suitable box, our work would have been much easier. The components would have fit more comfortably, and soldering would have been simpler too.

• Communication is key when working for a client. The lab we handed this off to had a clear vision of what they needed. If we hadn’t communicated regularly, we might have delivered a product that wasn’t useful to them.

What I Contributed:

I developed and integrated several advanced systems for the AuxROV, beginning with programming a Feather Adalogger to log voltage and current measurements to an SD card and perform power calculations. I set up and wired the electrical system, diagnosing and resolving a voltage drop issue by installing a suitable capacitor. Additionally, I soldered a surface-mount resistor for higher voltage tolerance and specced a new current sensor to manage increased current demands. My work included a comprehensive torque and force analysis to achieve balanced buoyancy, where I strategically added custom-cut foam and ballast weights for enhanced stability. I calibrated sensors to ensure accurate performance in stability and depth modes, refined PID control settings, and tested in both freshwater and saltwater environments. I vacuum tested the ROV before each test. I also resolved a compass calibration issue affecting navigation by recalibrating all sensors. Lastly, I wrote a guide for building the AuxROV, detailing electrical setup, wiring diagrams, assembly, and software integration.

Build Requirements:

• The mechanical assembly was not supposed to change significantly. Any additions had to fit within the existing electrical tube, and any external mechanical components had to attach to the ROV frame without modification. 

• Completing this project needed to be extremely low-cost, as funding was nearly exhausted.

• ROV needed to be able to hold depth.

Challenges Encountered and Solutions Implemented:

• The current sensor I initially acquired was unreliable, working only about half the time for reasons I couldn't determine. Eventually, I purchased a better sensor that functioned correctly on the first try.

• The ROV requires neutral buoyancy, but as previously mentioned, I couldn’t adjust the foam’s placement or purchase additional foam due to cost constraints. To achieve better buoyancy, I reshaped the existing foam into a parabolic form and attached more foam to the front. I also adjusted the weights to account for these modifications. A torque analysis helped me determine how to modify the foam and position the center of buoyancy on the ROV.

• We needed to attach a hook to the front that would remain open initially, then close and detach once it hooked onto an object, allowing a human to tow it. I designed a device that performed flawlessly in the test tanks; however, it failed completely in the ocean. 

• When the ROV was set to depth-holding mode, it would unexpectedly shoot upwards, flip upside down, or crash at high speed into the concrete side of the saltwater tank. I identified that part of the problem was due to an incorrect compass calibration, which I adjusted. Additionally, the PID controls were oddly configured, so I reset and customized them to better suit this ROV. After these adjustments, the ROV successfully held its depth.

Lessons Learned:

• When something doesn’t work despite thorough troubleshooting, it often makes more sense to invest in a better solution—such as using the budget to buy a higher-quality current sensor—instead of spending time trying to make an unreliable component function.

• As I learned, 3D-printed parts without modifications don’t withstand ocean conditions—the ocean always wins. Designing for a pool, as I frequently did with the NUWave robotics team, is vastly different from designing for the ocean. A device that performs flawlessly in a pool will likely fail in the ocean unless it’s designed with durability in mind.

• Keep detailed notes on debugging and logging throughout the project. Not every step needs documentation, but having a record can be invaluable if you encounter a similar issue later, allowing you to review your previous solution.

What I Contributed:

When I started this project, most of the parts for the line seeder system were already on hand. My goal was to assemble a working system from these spare parts and document the process as I went. I laser-cut electronics plates from DXF files in SolidWorks and soldered all the components onto the plate. I tested the system to ensure it worked as expected, with a magnetic switch to power it on and another switch at the front to control the motors. I also verified that the motors spun in the correct direction. For an initial trial, I tested it in a small freshwater tank, where it performed beautifully. Beforehand, I did a vacuum test to confirm it was watertight.

Build Requirements:

• The line seeder had to function based on the limited documentation I had and needed to look professional, as it was intended for handoff to another company for testing.

Challenges Encountered and Solutions Implemented:

• Limited documentation meant I primarily relied on pictures for the mechanical assembly, with no clear instructions on attaching components or placement. I reached out to a previous engineer who clarified the assembly process, helping me move forward confidently.

Lessons Learned:

• Always include thorough documentation for projects. Even simple designs need explanations to preserve knowledge for future users.

• Asking for help is a strength, not a weakness. When you're uncertain, seeking guidance is far more productive than guessing your way through.