A soap bubble blower entirely made from LEGO parts.
The machine was built on top of a LEGO boat hull, which was used in a somewhat reversed fashion, that is for holding fluid inside rather than floating in a fluid. There was a LEGO track acting as a conveyor belt, motorized with a PF M motor and pulling a number of empty LEGO 3×3 wedge belt tires in and out of the fluid. Once out of the fluid, the tires would pass in front of a fan driven by a 2838 motor. The whole thing proved reasonably efficient at generating bubbles.