For industrial applications concerning the nondestructive characterization of the near-surface material condition in terms of residual stresses, work hardening, phase transformation and formation of reaction compounds there is a strong demand for X-ray diffraction measurements on large components with complex geometry. Because many regions of interest on these components are not accessible with conventional laboratory or even mobile X-ray diffractometers, a novel center-free diffractometer with two cooperating robots named "Charon XRD" has been developed at MTU Aero Engines, Using a special optical measuring system to synchronize the two six-axis robots it was possible to achieve positioning accuracies that are comparable to those of conventional stationary diffractometers. This paper describes the design and functionality of Charon XRD and presents calibration and reference measurements, along with first measurements on aero-engine components.