A workpiece support assembly includes workpiece supporting roller assemblies each including a roller rotatably attached to an end of a swing arm. The roller assemblies are mounted to a frame forming a space between the rollers. A workpiece is positioned within the space and is supported in rolling contact by the rollers for rotation about its long axis. The space between the rollers is increased or decreased to support workpieces of various diameters by rotating the swing arms. The position of the rollers, and thus the distance therebetween are maintained or held by a swing arm lock that engages each swing arm and restrains the swing arms against rotation.