Cool Way To Sort Coins

That's really interesting.

Very cool. I've been working on the same project for detecting silver coins. I have constructed a slide from the rare earth magnets, which I have covered with some cardstock material. I can race a silver quarter vs clad quarter, silver dime vs clad dime, and the silver will generally slide slower. However, I have not been able to make it accurate and repeatable probably due to variables like friction, coin surface, etc. It would need some further work to be able to accurately identify the silver content. I don't know how much further I will pursue it, but it has been a fun experiment.

My next step was to place opposing magnets in a vertical orientation to eliminate friction, which is what he did with the vise. I may try that.

My current apparatus: