Abstract: The present invention is directed to an apparatus and method for determining the center axis of the largest solid of rotation obtainable from an irregular, elongated object such as a log or veneer block. The object is rotatably supported by two pairs of opposed wheeled supports positioned inward of the ends of the object. A motor-driven press roller maintains the object in contact with the wheeled supports and causes it to rotate thereon. The motion of the ends of the object as it rotates is used to define a locus of points at each end of the log. The centers of the largest circles which fit within these loci define the desired center axis.