the machine tool comprises a vertical support with a guide arranged thereon for vertical movement of a workpiece carrier holding a workpiece along an x - axis . two headstocks are each movable along horizontal guides in the y - direction . the guides form a frame , with its window closed by a louver provided with passage openings for the headstocks . this arrangement creates a laterally closed machining chamber which comprises vertical walls and does not present any obstacles to falling chippings . since the chippings need not be washed off , spray cooling may be used for minimum - quantity lubrication . in this manner , the liquid acting on the chippings is reduced .