Second Round of Manufacturing and Redesigns

Happy (Hopefully) Election Day! Please go vote if you have not. We've been busy at work working out the kinks of the Pian-Yo-Yo design. For the white keys snap ring, we reversed the core and cavity to allow us to eject the part rather have it stuck in the mold. However, the new problem we ran into is that four ejector pins is not enough to properly eject the part. The pins that are not as close to the edge are not able to push the snap lip out of its channel, and cause the part to warp and crack as seen in the picture (red piece). We have added more ejector pins to provide more, balanced force. Also, we are thinking about adding magnet slots so we can overmold carbon shims into the snap ring in order to add weight and make the yoyo more stable.

We have solid body injection molding parameters on the BOY machine (RIP Engel, you will be missed). However, the ball bearing press fit stud is slightly too big for the bearing ID, so we have fixed that dimension and plan to re-machine the cavity with a smoother finish. Also, there is a small area in the snap right lip that is consistently short, seen in the picture as the whiter area. We do not think that this will affect the snap function and it will be covered up. To fix it we could add another gate to the part, but this might be unnecessary given the time left.

For the black keys part, we experienced significant flash even when we were at minimum shot size on the BOY. To counter this, we added a riser to the mold and will re-machine and test to see if this helps.