Final Product! (BD #4)

Photographs of Components and Assembly

One of the big success of this yoyo is the attention to detail given in accordance to the theme. The small additions of embellishments added to the Mad Hatter and the Red Queen as well as the elegant wording on the snap ring and the smooth deliberate curves of the base. The spinning heads of the Red Queen and the Mad Hatter were the key features which drove a lot of the design. Unfortunately the added details of the Red Queen with the adjustments made cause the head to get stuck a bit. Changing the thickness of the Red Queen head would be a main adjustment. Additionally, adjustments to the fit between the snap ring and the base would be ideal in trying to make assembly a bit more manageable. The yoyo as a whole turned out excellently.

Specification Table

Update on Inner Silhouttes

Summary of Findings

The inner silhouettes are a conglomeration of pieces but after the final production run, all the pieces fit together beautifully! In the deliverable we only really had time to measure key features from each mold with the time limits but every piece was of the right size and width to sit comfortably on the spacer. We had some issues with the pieces being over constrained between deliverables but once that was rectified, there were no other serious issues with fit for the inner silhouttes. The color contrasts and depths turned out great (as can be seen in the pictures above).

Link to Paper Deliverable

Link to Video

Cost Analysis

Material and Labor costs (Yo-yo prototype)

Reflections

We considered our equipment from the very beginning of the design process so we ended up not having machinery as our main constraints, for example, we need that we did not have access to three-axis milling so we kept most of our geometries relatively simple. The lettering on the snap ring had to be made big enough or the machinery to be able to trace the details of the lettering. For mass production, higher volume-capacity machines with shorter lead times that yield higher quality finishes would be necessary. The number of molds may also be altered to allow for easier and quicker assembling time. Automation of some of the manufacturing process would reducing production time since the assembly of smaller parts, as well as the removal of excess material, were time-consuming by hand. This would require more reliable design. We were having trouble with parts sticking on certain molds for the heads, so having a design where the runners and ejector pins are able to eject the parts out smoothly and consistently would definitely help for mass production.

Recommendations for Improvement

The entire course was really interesting to be a part of. The most useful and intriguing parts of the course was definitely the time spent in lab and the lectures that we had specifically on manufacturing systems. When looking to improve the class, I’d suggest having shorter tests and PSETs. Preparing for and completing both was difficult in conjunction with the deliverables. They were definitely helpful but the shorter PSETS were best. I’d really like to see more time spent on additive manufacturing and on the breakdown of histories of machining. We spent a lot of time specifically with understanding and using thermoforming and injection molding and not as much understanding machining (outside of heating, cutting, and chips). I’d also suggest getting into the lab earlier and working with the machines earlier. The paperweight was a good first project but the setup is difficult for the beginning of the semester. Overall, the class was a great experience. I learned a lot from all of my team, Professor Chun, all the guest lecturers, both Anne and Ian, and Dave and other Dave. Thanks for a wonderful semester.

I’d recommend the spring course staff confer with the fall course staff on the way the class is taught and structured. Most feedback I’ve heard from both fall and spring 008-ers is that the fall class is better structured to set the students up for success (or at least to not set us up for failure), especially in terms of the pset and exam structure/schedule. I’d also strongly recommend not requesting this feedback as part of a deliverable that affects students’ grade, but making it an anonymous survey sent out separately from assignments.