[patrickk]

Coin sorting via weight or size would also be cool.

[aubreykilian]

Technically something with just different sized slots for the coins will work, and let gravity take care of the rest...

[obitoo]

Indeed, I had these as a kid in the 80s. Coins are simply inserted in the top right and roll down before falling into a stack. Hours of fascination! https://uk.pinterest.com/pin/303781937345711623/