Abstract: A routing machine for routing a non-linear groove in a flat extensive workpiece having a pattern in the form of a curved rib temporarily secured to the underside thereof. A reference roller in alignment with the routing tool engages a reference surface on the pattern while a cooperating roller is biased against the opposite surface, the rollers being driven so that the pattern is advanced to move the workpiece relative to the tool. The cooperating roller is mounted upon a table which is freely rotatable about the axis of the reference roller so that when the rollers encounter a portion of the pattern which changes direction, the cooperating roller is free to change its orientation with respect to the reference roller thereby enabling the workpiece to retain its initial orientation regardless of changes in direction taken by the pattern.