Abstract: A conveyor assembly including a conveyor defining a conveying direction and a carrier assembly operably coupled to the conveyor. The carrier assembly includes a carrier frame, a rotating mechanism coupled to move with the carrier and having a rotatable shaft with a rotary axis parallel to the conveying direction. The carrier assembly further includes a workpiece mounting frame coupled to rotate with the rotatable shaft. The invention is also directed to a workpiece treatment system having the conveyor assembly described above as well as a method of using the conveyor assembly to convey workpieces through a treatment system.