Abstract: A rotary cutter in which a bed knife is displacably mounted with relation to the rotary knife so that the bed knife, when actuated, travels a path between an operative position adjacent the rotary knife and an inoperative position remote from the rotary knife. An extendable linkage connected to the bed knife defines the operative position of the bed knife at the point of maximum linkage extension. Adjusting means connected with the linkage enable precise determination of maximum linkage extension which thereby insures precise setting of the bed knife and prevents bed knife travel beyond the operative position.