This package introduces one of the first invented machines, the Pulleys. Pulleys have been around for centuries, originally for transferring force with reduced friction and later for increasing force at amazing levels. Two pulleys combined with a belt create a belt drive that can reduce or increase speed and power. Cams and Cranks are used to convert reciprocal to linear motion. Learn all about these incredible Machines that even today are crucial components of most mechanical devices. Build an oil drill, a stationary bike, cranes, a moving figure, a machine blender and much more. Detailed instructions for 10 models are included.