Abstract: 3D metrology techniques are disclosed for determining a changing topography of a substrate processed in an additive manufacturing system. Techniques include fringe scanning, simultaneous fringe projections, interferometry, and x-ray imaging. The techniques can be applied to 3D printing systems to enable rapid topographical measurements of a 3D printer powder bed, or other rapidly moving, nearly continuous surface to be tested. The techniques act in parallel to the system being measured to provide information about system operation and the topography of the product being processed. A tool is provided for achieving higher precision, increasing throughput, and reducing the cost of operation through early detection and diagnosis of operating problems and printing defects. These techniques work well with any powder bed 3D printing system, providing real-time metrology of the powder bed, the most recently printed layer, or both without reducing throughput.

Abstract: To improve the operation of 3D printing systems, techniques are disclosed for a rotary 3D printer comprising: a main rotating support table rotating about a first axis and one or more secondary support tables rotating around a non-coaxial secondary axis; a powder supply assembly for distributing powder onto the tables; and an energy system for directing an energy beam at the powder to form a part. The main support table and secondary support tables can rotate in the same or opposite directions. Disclosed techniques include: grooved support table surfaces for improving stability of applied powder; reciprocating bellows for controlling a differential load on actuators that move the support tables; high temperature bearings or bushings for supporting rotary motion at high temperatures; and a mechanism for counterbalancing a weight of the part being built.