This paper introduces a novel method for the non-destructive inspection (NDI) of 3D printed parts using a millimetre- wave (mmWave) synthetic aperture radar (SAR) technique. A 15 GHz bandwidth radar is proposed to achieve high-resolution inspection, capable of reconstructing components with near-millimetre accuracy. The proposed technique integrates a state-of-the-art cooperative robotic arm to accomplish a parallel track pattern. The different measured perspectives of the component are fed to the SAR algorithm to report defects of the fabricated part. The radar employs a time-gating technique during data acquisition while the SAR post-processing algorithm uses a matched filter to enhance the target response, also known as pulse delay profile (PDP).