A fun demonstration of Bernoulli’s Principle. You've probably seen someone using a straw and blow at a ping pong ball and it would magically float in mid air. Well, who wants a cheap straw that you can just get off McDonalds when you can print your own? And this HAS A HOOP! You can even print multiple and try passing the ping pong midair!
Disclaimer: this is not my original design, just making toys for my kids. if you like it enough, please get it from https://www.geekslop.com/product/wooden-floating-ping-pong-ball-gadget . I am sure theirs work miles better and look much nicer.
*picture from geekslop.com