As part of my Design and Manufacturing II class I worked on a team of 6 to produce 50 yo-yos over the course of 1 semester.
The yo-yo consisted of 4 injection molded parts, 2 thermoformed parts, 2 vinyl cut stickers, 2 nuts, a threaded insert, a spacer, and a string.
Two sets of stainless steel molds were fabricated using CNC machining
Shallow cone spike geometry was chosen to minimize warpage and breaking
Spikes, fins, mouth, and body were all produced as one part to maximize consistency
Molds were sandblasted to produce smooth finish seen in final product
The nuts were insert molded into the inner bodies.
A threaded insert was screwed into the inner bodies to connect the two halves of the yo-yo
We checked the quality of our process by measuring the dimensions of each part we produced and analyzing the distribution of values. For consistency, each part was measured in the same 3 places and the average of those readings was taken. Every measurement is in inches.
Outer Ring + Inner Body
Interference Fit