A positioning device that is ideally suited for the assembly of optical components, particularly fiber optic components utilizing small-core single-mode optical fiber. The invention teaches a structure that can be used for 3 axis positioning and alignment wherein all of the control actuators are located on a common axis to improve operator adjustment efficiency and reduce repetitive motion strain. The device uses flexible elements to connect relatively movable parts, including parts which move orthogonally relative to each other. The device also has a lever arrangement which provides a mechanical advantage for the control actuators.