Final Project

In our final design, we added some final touches and worked to find solutions to the issues from prototype 2. First, since our mechanism involving the servo motor tipping a book and releasing a ball was warped as a result of painting it, we decided it was necessary to remake that section of our RGM. Additionally, since our pulleys had a tendency to come loose, we decreased the amount of excess string we were using in hopes of making them more consistent. Given that a major issue we faced in our second prototype was the tap missing the limit switch, and therefore not setting off the second set of electronics, we added a small piece of cardboard to the limit switch to increase the chances of the tape successfully hitting it. For aesthetic purposes, we changed out the brown fabric for red fabric and added sticky notes around the board. Finally, we powered the picos via an outlet instead of using a computer to save space. These alterations can be seen from the pictures below.

The final design of our RGM, complete with labels, hidden lines, center lines and dimensions can be seen in the technical AutoCAD drawing below:

During the Expo, the majority of our machine demonstrated its repeatability through its consistency over three consecutive runs. Difficulties during previous prototypes, including the tape missing the limit switch and the book landing in an inconvenient location proved to be lessened through the alterations made between the last prototype and our final design. However, our first pulley, which also served as the transition point between our group and the group before us, gave us some difficulty. The ball from Group B’s ramp, while it was aligned with our cup, missed the transition on every single run. Therefore, the ball unfortunately had to be placed into our cup in order to trigger our machine instead of operating with a seamless transition. Additionally, the platform that prevents the sticky notes from falling (and is triggered by the same pulley) also didn’t always operate as intended, likely due to some misalignment as a result of mishaps with the pulley. In the end, our first run had 2 interventions, our second run had 1 intervention (video below is from the second run) and our final run had 0 interventions. In comparison to the previous prototypes, this final version was definitely more independent and reliable, demonstrating improvement and the learning curve associated with building a Rube Goldberg Machine.

Overall, our group is extremely satisfied with how our project turned out and its relative consistency. We knew that our design was ambitious, so being able to execute our plan and overcome the electronic and mechanical difficulties that we faced along the way was extraordinarily satisfying. We are especially proud of how our recursive/most complex element turned out, along with our integration and coding of our electronic components. If we had more time, based on our performance at the expo, we would’ve devoted more energy to frequent and effective communication with Group B in order to develop a more successful transition between our machines. Withstanding this transition, our machine operated relatively well as we were able to transform our original sketches and ideation into a functional product.