A motor-driven machine-tool unit such as a multi-axis turning head or a motor spindle, having a stator unit and at least one rotor unit that is rotatable about a rotation axis, wherein the rotor unit comprises at least one tool receptacle unit having a tool clamping device that is adjustable in a longitudinal direction of the rotation axis and impingeable with a clamping force, for fixing and bracing a releasably fixable tool, wherein comparatively high requirements are met, in particular, in terms of the accuracy of the machining and/or the reliability in the machining. According to the present invention, this is achieved above all in that at least two clamping force sensors are provided for detecting the bracing of the tool clamping device, in particular the clamping force that is caused in the fixing and bracing.