Abstract: An object transport apparatus (10) is provided for the purpose of transporting an object (19), usually a semiconductor wafer, to various points within a planar circular zone (Z). The transport apparatus (10) includes a motive power subassembly (12) for generating rotational motion and delivering it to an arm subassembly (14) rotating about an elbow axis (20) and, through an eccentric drive subassembly (110) to a hand subassembly (16) adapted to support to wafer (19). The hand subassembly (16) rotates about a wrist axis (21) which is parallel to but displaced from the elbow axis (20) in an independent fashion from the rotation of the arm subassembly (14). The eccentric drive subassembly (110) incorporates complimentary pairs of cam drivers (111, 112) connected by cam linkages (120, 122) to deliver rotational motion from the elbow axis (20) to the wrist axis (21).