Abstract: An x-ray unit is provided which includes an x-ray device for producing x-rays. A base holds the x-ray device, which comprises an x-ray source for positioning over an area of concern, and a rotatable x-ray source support column for allowing movement of the x-ray source. The total rotational motion of the support column is greater than 360.degree. relative to the base. Mechanical end of rotation stops mechanically defining total rotational motion of the support column. The x-ray source is capable of clockwise and counterclockwise movement from a parked position.