Investigation on Laser Scanner Synchronization via Advanced Beam Path Analysis in 3D Additive Manufacturing Systems

In selective laser melting processes, the precise synchronization of mirror motion and laser illumination is one of the major influential factors, determining the quality of additively manufactured metal parts. Utilizing a novel laser beam diagnostic approach, we are able to determine timing errors on the scale of a few [micro]s. Since the method does not involve the structuring of test specimens with certain processing windows, the analysis is applicable over a wide range of power levels, allowing the direct observation of power dependent laser switching delays, and their influence on the aspired shape accuracy. We present investigations of power dependent start/stop-point displacement over a variation of 400 W and devised a quick and convenient calibration procedure.Keywords: additive manufacturing, 3D printing, selective laser melting, laser beam diagnostics, scanner synchronization