A stud positioning tool includes an elongated bar that has a first end, a second end, a front side, a back side, a top side and a bottom side. The assembly and method includes a vacuum manifold having a cavity which is connected to an evacuation source for drawing a vacuum on the cavity, and an opening on the manifold of a given size and shape and communicating with the cavity. The fiber also includes at least one longitudinally extending region having a thermal coefficient of expansion that is different from the thermal coefficient of expansion of the cladding.