Marble-powered phone charger built by Engineezy uses falling steel marbles and a stepper motor to charge a phone, but only for about 30 seconds.

[Martin] of the band [Wintergatan] is on his third quest to build the ultimate musical marble machine, and that means dropping marbles with maximum reliability and precision timing. Working through ...

Marble machines are a fun and challenging reason to do engineering for the sake of engineering. [Engineezy] adds some color to the theme, building a machine to create 16×16 marble images automatically ...