Abstract: The invention relates to a control system for setting the crown and/or steer on the rolls of a cluster mill such that the adjustment collars are all driven together but substantially in the desired final ratio to one another throughout the movement. The control system derives a separate control signal for driving each eccentric collar. The circuits for deriving the control signals include means for deriving from crown and steer magnitude signals, a series of crown and steer datum signals, one for each collar, which are proportional to the respective magnitude signals in selected ratios, the crown ratios being preselectable by a selection means and means for progressively increasing the magnitude signals from zero to the desired value.

Abstract: A milling machine for milling a face of a metal workpiece has a cutter positioned to act on the face of a workpiece passed through the machine. A control means is employed to ensure that the depth of cut on the face remains at its preset value regardless of variations in thickness of the workpiece entering the machine.In a preferred arrangement, the machine has a pair of cutters positioned to act on opposed faces of the workpiece. The control means then ensures that the depth of cut on each face remains at its preset value.This is different from known machines in which the cutters are arranged to cut the faces so that the outgoing thickness of the workpiece remains the same regardless of variations in thickness of the workpiece entering the machine.