Method of friction welding workpieces by adjusting a sweep length

A method of friction welding a first workpiece to a second workpiece, includes the first workpiece with a first faying surface having a first faying length, the second workpiece with a second faying surface having a second faying length, the second faying length greater than the first faying length; positioning the first workpiece adjacent the second workpiece; reciprocating the first workpiece and the second workpiece against one another, the first faying moves relative to the second faying by a sweep length, a temperature at the first and second faying surfaces increases to create a weld interface; each of the first and second workpieces are consumed into the weld interface, adjusting the sweep length the sweep length remains equal to a difference between the second and the first faying lengths; and stopping the reciprocating and allowing the first and second workpieces to cool to weld the first and second workpieces together.