A positioning device for positioning a movably mounted portion of a workpiece. The positioning device includes an attachment structure, a rod, a flange assembly and an engagement mechanism. The attachment structure includes a rod aperture and is coupled to a robotic apparatus. The rod is disposed within the rod aperture and is slidably positionable therein. The flange assembly is coupled to a distal end of the rod and includes a flange structure. The flange structure is rotatable relative to the rod and engages the movably mounted portion of the workpiece. The engagement mechanism is coupled to the attachment structure and is operable for moving the rod in an axial direction within the rod aperture. The engagement mechanism applies an axially directed force to the flange assembly to maintain the flange structure in a stationary position relative to the movably mounted portion of the workpiece when the movably mounted portion of the workpiece is moved relative to a remaining portion of the workpiece.