Cookie Monster Yo-Yo Manufacturing
Yo-Yo Design
Design Overview
Press Fit and Thickness
Mold Designs
Face Mold
Top Ring Mold
Body Mold
Cookie Molds
Milling and Injection Molding Difficulties
Long Machining Time
Press Fit dimensions require long machining time
Need to optimize machining operations
Utilize different tool sizes to minimize tooling time
Debugging CAM
Determine errors that are causing molds to be defective
Manage quality control
Injection Molding and Draft Angle Issues
Ejection Issues in IM process due to multiple factors
Too small of draft angle, no ejector pins, lack of mold release, incorrect IM settings, etc.
Fine-tune IM parameters to eliminate flash, short shot, and other issues
Data Collection
At the end of the project, we collected the 50 yo-yos we produced and measured them to see how closely they aligned with our initial design specifications. Throughout the term, our press fit spec changed from 0.010” to 0.0145” because we had not accounted for enough shrinkage in our initial calculation. In the end, we found that the “Ring Inner Diameter” and the “Body Outer Diameter” were both larger than our design specification but both had good distribution. The interference fit was smaller than expected but all yo-yos did have an interference fit which was encouraging. Moving forward, we will most likely mess with the cooling time, packing temperaturepacking pressure to help optimize the interference fit.
