The MACRO-SK is a grinding machine especially designed for machining the internal contours of stators, and it sets new standards in efficiency and precision for machining the internal diameter of stators. The machine concept of the Macro-SK enables the user to grind various types of stators on the machine, e.g. Gerotor and Geroller. The machine has two spindle arms when fully equipped. During grinding, these spindle arms are lowered in a vertical direction into a stack of stators that are clamped in a fixture. The vertical grinding direction proves to be a major advantage in this regard compared to other machine concepts, because the cooling lubricant is channeled specifically into the grinding gap, thus achieving larger grinding feed values. The grinding time, and thus the entire cycle time of the process are reduced by having higher grinding feed rates.