I'm actually SUPER excited to bring this model to you! I really wanted a 3D printed yoyo because I have been doing yoyoing for about two and a half years and I love 3D printing. I watched some videos on it and decided that I would design my own, so I set to work. I printed this out at 90% infill and it was actually still very light for a yoyo, so I recently changed it to some thicker parameters to make it heavier. You need 19mm pads for the response and a Size C bearing. This one plays unresponsive, but sometimes it just comes to your hand randomly( I don't know why, but I think it's because of print defects). I don't think you need supports and I don't know what side nut and bolt I used, but the diameter of it is 8.5mm and you can just get the nuts and bolts at the hardware store. The bolt length doesn't matter because you can just cut it off carefully( I did this and It was kind of hard to put on, but I was able to get it with a hacksaw). I really hope you like this and it's actually one of my favorite projects so far! :)
P.S. If all of this yoyo stuff doesn't make any sense to you, I'll put in some links to yoyo websites and the differences between unresponsive to responsive yoyoing.
YoyoTricks https://yoyotricks.com/ YoyoExpert https://yoyoexpert.com/ How To Yoyo https://yoyotricks.com/yoyo-tricks/beginner-tricks/