A ceiling-mounted hardware assembly and related mechanical, electronic or software controls that form the structure used to mount, support and facilitate positioning of the x-ray tube assembly sub-system of either a diagnostic x-ray system, therapeutic x-ray system, or an x-ray system designed for use as a radiation therapy simulator. Some designs also support and coordinate the movement and positioning of a radiographic cassette or image receptor assembly with respect to the position of the x-ray tube, e.g., a C-arm assembly. This device is considered to be a component of an x-ray system.