Systems, methods and devices for implementing automatic control of focal spot Z axis positioning are disclosed for use with an x-ray device having an x-ray tube positioned within a housing and configured for thermal communication with a temperature control system. Control circuitry, and a position sensing device configured to determine the distance between the focal spot and a reference point related to the x-ray device, are coupled with a control module. The position sensing device sends information concerning the relative distance between the focal spot and the reference point to the control module which compares the received information with a predetermined desired distance. If the received information varies by an unacceptably large margin from the desired distance, the control module sends a corresponding signal to the control circuitry which causes the temperature control system to implement an appropriate change to a heat transfer parameter associated with the x-ray device.