US Patent 10112260 Aligning lasers of laser additive manufacturing system

Methods for aligning a pair of calibrated lasers of a laser additive manufacturing system in an overlap region in which the pair of calibrated lasers selectively operate are provided. Respective first and second plurality of layers of a test structure are formed in the overlap region of the pair of calibrated lasers solely using a first calibrated laser of the pair of calibrated lasers and then solely using a second calibrated laser of the pair of calibrated lasers. The test structure forming creates an outer surface of the test structure corresponding to the overlap region. A dimension(s) of an offset step(s) created between the first plurality of layers and the second plurality of lasers in the outer surface of the test structure is/are measured. The lasers are aligned by applying the dimension(s) of the offset step(s) as an alignment correction(s) to at least one of the pair of calibrated lasers.