Grilled Cheese, the YoYo

This is a fixed axle (no bearing) square yoyo. It has been designed to be printable in one piece with no assembly required, just need a yoyo string. 

Inside the gap, not visible from the outside are 6 holes that serve as the yoyo's response system (what makes it go back up the string when you tug)

The dimple is there for pull starts and other tricks. 

Recommended to print it in as thin a layer lines as possible (.05, .07 etc) in order to not wear down strings and have best playability. Ideal weight varies person to person but I found 56 grams to be idea, so slice accordingly with extra perimeters.