A three DOF SCARA arm, adapted for transporting semiconductor wafers, includes an end-effector assembly at a distal joint of the arm. In one configuration, the end-effector turns a workpiece over. The arm includes a support column having an open column assembly that projects above a base. Within the assembly, a Z-axis drive energizes extension and retraction of a hollow tube carried by the support column. A shaft, rotatable about the Z-axis and having a distal end furthest from the support column's base, receives an arm assembly. An arm-assembly rotary-drive energizes the shaft's rotation. An arm base-plate, secured to the shaft's distal end, supports the arm assembly therefrom. The arm base-plate carries a wrist joint that is displaced from the Z-axis, and receives the end-effector whose rotation about a wrist-joint axis is energized by an end-effector rotary-drive.