As part of a manufacturing class I worked in a team to design and manufacture a production run of 50 yo-yos using thermoforming and injection molding processes. The aim was to produce a high-quality yo-yo with repeatability in the manufacturing process.
One of Dieter Rams' 10 Principles is "Good design is aesthetic." Only well-executed objects can be beautiful. The design eliminates the addition of electronic components so most time was spent on the physical parts: their material properties, manufacturability, and aesthetic design.
The key motif of the yo-yo is a trident symbol made from a copper plate, using a water-jet machine. Poseidon is the greek god of the ocean who is classically depicted as carrying a trident as a weapon. The symbol is elegant, clean, and aesthetically appealing.
For more details about process optimization and a peek inside the yo-yo, visit team's website is here.