The shaft was the vertical axis that transmitted power from the cartridge to the grinding stone.
This device consisted of a lower timber and an upper iron frame. At the top we find the iron neck, a metal part that crossed the stationary stone base which, together with the hub, transmitted the force to move the stone. The hub was a metal part placed horizontally and which held the grinding stone.
The filoseta, at the upper end, hit the gutter and allowed the grain to fall between the stones.