In Fall 2014, I took the class 2.008 (Design and Manufacturing II) at MIT. In a team of five, we created 50 yoyos over 10 weeks, using high-volume manufacturing processes like injection molding and thermoforming. We optimized the process to account for shrinkage, flash, and maintain specs for critical dimensions.
- Yo-Yo Design
- Preliminary Mold Design: Retaining Ring
- Manufacturing Molds: Thermoform
- Process Optimization: Machining
- Process Optimization: Thermoform
- Process Optimization: Retaining Ring
- Production Runs
- Cost Analysis & Recommendations
Design: We used Solidworks to CAD the parts and their molds to look like the Wheel of Fortune. We designed an overmolded game board.
Manufacturing: We used Mastercam to create toolpaths needed for machining on the CNC mill and lathe. The free spinning Wheel of Fortune spinner, overmolded game board and retaining ring are all injection molded. The plastic yoyo cover is made from thermoforming.
Optimization: I worked on optimizing the thermoformed plastic cover. This required changing input parameters while measuring diameter over multiple runs, to track how the output parameters changed over a production run.
Improvements: We would like to design for robustness of manufacturing, needing more tuning to get the overmolding right, since the letter grid is so thin compared to the large disk. In addition, we’d like to change the gate location on retaining ring and body to ensure a better fit.