Introduction

Welcome to another edition of a Jonah and Erick collab. For this midterm, we wanted to make something interactive and satisfying for the user. Taking inspiration from the “Unnamed Project” (what we called the OG, sometimes called the water drop project) and the Whack-A-Mole project, we set out to create a path through music. This project was difficult, time-consuming, anxiety inducing, and took every ounce of creativity from us and then some. However, it worked marvelously, and we could not be prouder of our finished product.

Process

The first part of the journey involved general sketching and choosing our mechanism. The mechanism that was chosen from 507movements was #138.

Our drawings planned around a square structure that would mimic a sound wave. The square on top would signify music notes and flow in a purposeful pattern. The shafts would move up and down at certain positions, which we achieved by having a teardrop shape around a square axle that was laser cut into 6 different positions.

After finishing the drawings and fleshing out the concept, we moved onto cardboard prototyping. Very quickly, friction became a problem, as the prototype would not move. We also learned that the way we had designed our squares to move up and down was fragile and would break instantly. This marked the emergence of the redesign of the squares and their necks, as well as the introduction of the stoppers that would prevent the cams from sliding.

Afterwards, we made a model fully of wood. This was where friction really played a role as the project did not move even a single inch. We considered using graphite and wood lubricant, but found a better alternative. ACRYLIC. The movements were working well soon after.

After printing our guide plates and cams in acrylic, the model moved well. As the cams slid more, we added stoppers to the axles. The square axles proved to help us develop the key positions. After seeing that one layer stoppers slide too much and did not stop anything, we doubled up the layers to have them fulfill their purpose. The guiding plates allowed the squares and their necks to stay straight and not fall off the cams. Overall the structure stayed strong and was actually surprisingly rigid.

Successes and Failures

Throughout this process, our biggest enemy was battling friction. The initial prototype made out of cardboard demonstrated the overall structure of the device, but it did not move properly, which was to be expected with a cardboard prototype. As we began substituting cardboard parts for wooden ones, we quickly became aware of the fact that the friction was going to be too much to function. We ended up testing a prototype made entirely out of wood, and sure enough, the device struggled to turn, with the key friction components being the individual tear-drop cams and the guide rail of the axial rods. To mitigate this, we designed our final prototype guide rail and cams out of acrylic and prepared to use some kind of lubricant to help with any leftover friction. Much to our satisfaction, the acrylic substitution alone was all that was needed to make the device functional, and to help ensure the longevity of our device, we chose to leave it as is instead of adding any sort of lubricant to the moving components.

Another key barrier in our design was the overall size of the device. We chose to have nine mechanisms arranged in a 3×3 square grid. Due to the alignment, this arrangement severely limited the size of our cams, which in turn limited the range of motion of the axial rods attached to the moving squares. This meant that the vertical height traveled by the squares had an upper bound, which was a little disappointing. Solutions included expanding the width of the box or coming up with a creative way to offset the axial rods, but the former threatened to impede the visual appeal of the device while the latter had the potential to introduce a number of design challenges that we did not want to dive into. With that in mind we chose the maximum size that could still comfortably be used. As you turn the device, you can see that the tear drop shaped cams come close to coming in contact with one another, but do not actually interfere.

Overall, we were incredibly pleased with the performance of the device. Mostly to the versatility of the design. Much like the water drop device, from which this project was inspired, the device seems unlikely to break because the forces at work are relatively small compared to the critical loads of the components, and the lack of lubricant suggests that the device will not require maintenance to remain functional. With that in mind, we are confident that the device will continue to be a success, assuming that it is treated with care by its users!

 

Costs
Plywood (2 sheets at $5/sheet): $10
Acrylic (1 sheet at $8/sheet): $8
Adhesives: Negligible
Machine use: Shared resource
Time (25 hours at $15/hr): $375
Total: $393