This is a double Helical Gear set (also known as a Herringbone gear set) that is designed in order to learn more about the equations involved in creating gear sets (specifically helical and herring bone gear sets).

The model itself is really fun/addictive to play around with as a fidget toy and is a great way to demonstrate to children how gears work. In the future I plan to make more models like this with the purpose of demonstating how different gear ratios affect the power and speed outputs of a force. 

Happy Printing!