This project was the first large-scale project done in the semester, from designing the mechanisms, creating models and prototypes, revising and changing the design based on the performance of the low and high-fidelity prototypes, and finally creating the final product to be post processed. All in all, although there were some stressful and frustrating times, this group project was a great learning experience that was overall fun to complete.
Initial Designs
With the initial idea for our project to be the man who teaches Link the Song of Storms from the Legend of Zelda: Ocarina of Time, we tried many different mechanisms from the 507 Mechanical Movements to give him some life. For our idea, we wanted to incorporate his music box attached to the front of him, having the user’s movement of the crank to cause him to move his crank. This would be done by the use of many gears to translate the rotational movement of the user’s crank to a rotational crank of the man. This “crankception” idea was further expanded upon, using a sliding crank mechanism (Movement #92) to move music notes around the music box. These were the first drawings of how we expected our project’s inner mechanisms to work.
Using advice from the Teaching Team, rather than utilizing a bevel gear mechanism as our primary movement, simplifying the design to only include same plane gears (Movement #24) would make the construction of the model much easier as well as perform much more reliably.
Cardboard Model
With the simplified model, we progressed and built our first low-fidelity model to test if the mechanisms worked as intended. Using the laser cutter to print out the external body as well as the different gears, we were able to tape together the outside pieces, since the cardboard’s thickness could not support the finger joints of the design, and affix the gears using 3/8” wooden dowels. Printing out the gears in wood to simulate a smoother motion, our prototype was able to properly move the man’s crank as well as provide a rotational motion for the music notes on top of the box. For a low-fidelity prototype, the movement is what we intended, giving us confidence for a higher fidelity model.
Wood Model
Unfortunately for our team, translating our success in our low-fidelity model to a fully wooden model was more difficult.
The first issue we came across was our gears. When printing out another set of gears for the wooden model, a slight mishap in our sizing of the gears caused major misalignment between them, producing a very unreliable and janky movement. Having to fix this issue, the ultimate size of our gears for the wood model failed to fit our previous intended positions for them, having them either too close or too far from one another, producing a clunky motion or no motion at all. To fix this issue, we measured the distance between each gear using digital calipers and modified the distance to the best fit. Once we made this change to the positions of the gears, the movement of the gears was much smoother. Additionally, we doubled up our gears in order to keep the movement consistent.
Another issue that arose while making our wooden model was the inconsistent smoothness of the movement of the user’s crank. We noticed that the constant rotational movement of the user’s crank when testing would wear down the sides of the hole holding the connected axle. This would eventually erode the sides, causing the gear hole to be looser. To fix this, we utilized a bearing in place of a bare hole. This would require measurement of the bearing to be tightly snug inside a new, bigger hole in the side of the torso and the shaving down of the axle to fit within the bearing, but the result is a much more reliable and smoother motion from the user’s inputted motion.
Final Touches + Post-Processing
Once our model’s functionality was working as desired, the next steps were adding the finer details to the project to make it more aesthetic. Printing a smaller box to affix to the top surface of the man’s torso, we also included engravings of the man’s face and ears on the left and right sides. To achieve this, we converted a .jpg file of the man’s face and converted it to a .svg file that could be read in Adobe Illustrator and engraved using the laser cutter. Additionally we added the cutting of music notes for the music box, cutting out acrylic faces of the model, creating a metal handle for the user’s crank, creating the man’s arm connected to the music box crank, creating a vinyl pants sticker. Additionally, aside from additional parts, post-processing included the sanding of the final model.
Similarly, we engraved images of a measure of music notes in a circular shape with a hole in the center to attach to the end of the sliding crank mechanism. With this attached, it looks as if the cranking of the music box causes music notes to fly out of the top of it.
Because much of the mechanisms are within the torso of the man, we decided to print out acrylic faces of the torso and music box so that the user could see the insides of the man as they were cranking. This was a simple replacement, reprinting out the desired faces with acrylic.
With different iterations of the handle, we decided to cut out a 0.5” thick aluminum plate as the handle for the model. Using the waterjet cutter, we cut out a square piece with the same music engravings as the music notes and affixed it to the dowel connected to the main mechanism of the model.
To create the man’s arm connected to the music box crank, utilizing a similarly cut piece to the sliding mechanism, we were able to affix the arm joints of the man to the side of the box and the outside crank of the music box. Now, as the music box cranks, the man’s arm will move as well.
Lastly, we used the vinyl cutter machine to produce a blue sticker to attach to the bottom of the man’s torso, mimicking the look of blue pants.
Tidying up the look of the model as a whole, to rid the man of any laser burns caused by the laser cutter and any roughness around the edges of the model, we sanded the external portions of the man.
Finished Product + Reflection
With the final touches done, we are really happy with how the final product looks and functions. We are super proud of how much effort our group put forward to produce this final product.
If we were to do a similar project, we would improve:
- Post processing – perhaps spending some time staining the wood
- Change the finger joint spacing – using less finger joints
- Spend more time on low-fidelity models before attempting to create higher-fidelity models – working out any kinks before progressing
Cost Breakdown
- $45 for 3 square yards of 1/4″ thick plywood
- $15 for 160 square inches of 1/4″ thick acrylic
- $10 for 3″ by 3″ of 0.5″ thick Aluminum plate
- $7.50 for 18 oz of wood glue
- $3 for three 3/8″ by 12″ wooden dowels
- $1.50 for a vinyl sheet
- $0.50 for one 3/8″ steel ball bearing
- $900 for 3 laborers x 30 hours of labor each at $10/hr
- $0 for equipment usage (Thank you OEDK)
Total Cost: ~$982.50
