Although they may look alike to us, each machine has different functions: some cylinders grind the wheat, some break it down, and others press the meal.

The mills have four cylinders that allow two batches of wheat to be ground independently. The wheat is placed in the top, and a set of two parallel rollers work to ensure the wheat falls evenly between the two grinding cylinders. These cylinders move in opposite directions and at different speeds, which means that the slowest cylinder holds the wheat in place while the faster cylinder grinds it.

The resulting product is collected at the bottom, via a lifting bucket that is sent to the "pansichters", which then separate out the flour.