Experimental sampling of the Z-axis error and laser positioning error of an EOSINT M280 DMLS machine

The Z axis table motion errors and laser positioning errors an EOSINT M280 were evaluated using a set of standard metrology techniques and instrumentation. While the linear displacement error of the table is quite low (4.5 μm), straightness, yaw and pitch errors on the other hand were significantly higher and may contribute from 20 to 30 microns of form and orientation tolerances over a large size build. The performance of the laser positioning system was much worse. The system consistently positioned the beam short by a significant amount at the edges of the workspace. A designed artifact was produced, and used to evaluate the laser performance against a set of tolerance controls extracted from the ASME Y14.5-2009 Standard. The largest scatter of values was observed on the position of small circular features located over the working area. The largest tolerance magnitude (239 μm) was calculated as the combined effect of location, orientation, size and form errors in the trace of a large quadrifolium etched over the working area of the laser. The errors measured in this research are substantial.