Final Design

After 12 weeks of lab and countless hours of zoom meetings and extra shop time, we're proud to present our final yo-yos!

Our 50 yo-yos

Exploded view of our final design

Our yo-yo is made up of 6 parts, the body, PCB, pyramid, thermoformed letters, cover, and rim. Our custom PCB screws into the yo-yo body, and an extrusion inside the pyramid sits around the button. Ledges on the sides of the pyramid catch on the white cover and prevent it from falling out. The thermoformed letters press into the hole in the white cover which sits on a lip inside the body. The rim forms a press fit with the body and holds all of the pieces in. Because of budget constraints, we were limited to 18 PCBs, so, in the remaining yo-yos, we replaced the PCB and buttons with a foam piece to support the pyramid and mimic the button pressing motion.

Manufacturing Overview Video 

When assembling our yo-yos, we noticed a couple of things that we would want to change to make it easier to mass manufacture. First, the pyramids and PCBs both have a direction that they must be in to fit with the other components. The pyramid is an isosceles triangle and the extrusion is closer to one side, so we needed to pay attention to this when placing it into the white cover. For the PCBs, one of the screw holes is closer to the edge, so for each yo-yo half we had to ensure that LED1 was positioned away from the gate on the yo-yo body. Making the screw holes an equal distance from the center and the pyramid an equilateral triangle with the center directly over the button would make the assembly process go faster. For the pyramid, which is a smaller part, we could also design a multi-cavity mold to make the injection molding process quicker. In an ideal future design, the CITGO thermoformed letters should most certainly be cut to the right diameter to they are supported by the lip of the body. additionally, the mold for the lettering should include its own small lip so that way it clicks up into the white cover securely.

Overall, our finished yo-yos look great, stay together when spinning, and are fun to use. Special thanks to Professor Chun, Paul, Alex, Jenny, Dan and Kiely for helping us along our yo-yo making journey.

Link to final presentation slides.