Abstract: A calender especially suitable for use with rubber and plastic material. One of two opposed rolls is movable toward and away from the other through direct action of long-stroke fluid actuators that move the bearing boxes on opposite ends of the movable roll. Roll spacing is directly sensed by position-sensitive transducers acting between opposed bearing boxes and responsive to the relative roll positions. The transducers signal changes and initiate correction to retain roll spacing at a set distance. The fluid actuators are controlled to separate the rolls upon power failure and to prevent roll contact in the event work product is not between the rolls.