Yoyo

This yoyo works quite well. Shiny surfaces touching the string make it more efficient than wooden toys. With less energy loss it can roll almost forever!

How to assemble? Use thin, strong synthetic string. Make figure 8 and a self tightening loop to make it not slip when the toy rotates. You can put a drop of oil on it. and the sides of the gap.
The inside pin can be superglued, or use bluetack, chewing gum, or just press it firmly to make it stay put.