Final Project – Nancy Lindsey and Kenton Roberts
For our final project in ENGI 210, we chose to build a something fun using Mechanical Movement 158. We also took great inspiration from Mechanical Movement 223, though we took this in a different direction thanks to a suggestion from Dr. Wettergreen. Ultimately, we chose to use “nautilus gears,” which fit brilliantly with our underwater theme. When combined with two arms fitted onto the spinning gears, we envisioned a model that would depict a shark continually chasing a fish, but where the fish would always escape the shark’s grasp.
An early drawing of our “shark bait” idea.
Once we had laser-cut the nautilus gears and determined the proper distance between them, we were able to create a low-fidelity prototype. We used this to show the desired motion of the model and to estimate the ideal lengths of each wooden arm. In this prototype, we were successfully able to show the fish “dodging” the shark at each revolution.
Low-Fidelity Shark Bait Prototype
“aaaaah don’t eat me Mr. Shark!”
This proof-of-concept motivated much of our later progress. Once we felt the gears moving together and saw the inspiring struggle of our little fish, we were excited to further develop this prototype. From the beginning, we wanted our final prototype to be really solid and sturdy, so we started our medium-fidelity prototype by creating a base out of multiple layers of plywood. Then, we chose to cut our nautilus gears with three layers of laser-cut wood. We planned out how to put everything together using dowels and a crank on the right-hand gear.
The final prototype would prove to be the biggest challenge. This was a lot of painting, fitting things together, lubricating the rotating wood interfaces, and gluing things together. We also used the water jet cutter to create our beloved fish and the shark out of aluminum, and decorated our blue base with an ocean ecosystem using the vinyl cutter. With some careful planning, we were able to assemble everything without accidentally wood-gluing one of our rotating components, and we are extremely happy with how the final product looks.
Video: Shark Bait Demo
Despite our many challenges while creating “Shark Bait, Ooh Ha Ha,” we learned to just keep swimming, and this mindset brought us to a wonderful prototype that we can be very proud of, and which will hopefully stay in the OEDK for years to come.
Adobe Illustrator Files:
We have attached combined Adobe Illustrator files for the decorative flora and fauna seen in our prototype, as well as the laser cut components that make up our model.
OVerview Slides:
Cost Analysis:
Plywood (3/4 in.): ~1.9 square feet @ $1.59/square foot: $3.09
Laser-Cutter Wood (3/16 in. plywood): 2 sheets @ ~$5/sheet: $10.00
Wooden Dowels: ~$1.00
Aluminum: ~15 square inches @ $0.02/square inch: $0.30
Wood Glue and Epoxy: ~$3.00
Varied Machine Use: ~$30
Lab Assistant Aid: 45 minutes @ $11/hr: $8.25
Labor: 45 hours @ $10/hr: $450.00
Overall, the total cost of our final prototype was about $505.64. The vast majority of this was from our own personal time spent designing, planning, and building our prototype, so the cost was greater because it was a novel prototype. This is a surprisingly large amount, but it makes total sense after all of the time that we spent to create it.
-Kenton Roberts and Nancy Lindsey
