Systems and methods for separating harvested crop product from twigs, dirt, dust, and other debris. A disk to be used in a harvester includes a first segment and a second segment and is configured to cooperate with adjacent disks axially mounted on a common rotational shaft, and radially cooperate with disks mounted on a parallel rotational shaft. The disks are used in a roller assembly or a harvester, and gaps between cooperating disks remain effectively constant during operation.
