It's Cheap But Not Cheaply Made A Unique Coffee Timer, A Real Working Engine, A Novelty and A Great Gift Option!
This engine is driven by the temperature differential between the top and bottom plates. To create enough temperature differential, simply put it on a cup of hot water.
When in good condition, that is, after working for a while and being lubricated, it can reach a speed around 220-250 RPM driven by boiling water. Please refer to the video attached to learn how to operate and lubricate.
It can run for a long time providing there are continuous heat supply.
The flywheel is made by metal too.