Replies to post #34903 on Sigma Labs Inc (SASI)

[jpi]

Looks like Godfrey is going it alone...

Wednesday, August 5 10:50 AM - 11:20 AM
Part qualification and validation are essential for industrial AM adoption. This session will highlight the new in-process monitoring and post process inspection technologies that are being developed for AM applications to overcome the time and cost constraints of traditional methods.

In-Process 3D Geometry Measurement and Reconstruction for Direct Metal Laser Sintering

AM3D2015-1513
Donald Godfrey
Engineering Fellow / AM Lead, Honeywell Aerospace
Despite the significant promise of 3D Printing technologies such as Direct Metal Laser Sintering – DMLS – three problems still remain that inhibit further adoption of the technology: metallurgical quality, geometric accuracy, and production speed / productivity. Measuring the geometry of a part during the direct metal laser sintering additive manufacturing process is a major challenge of in-process quality monitoring. This paper describes a novel technique based on well-known image processing algorithms to extract calibrated geometry information from a photograph of each layer of the part. The technique provides near real time geometry information during the DLMS process. The resolution and measurement error of this method are discussed. This paper will also demonstrate that the technique is analogous to standard measurement techniques such as optical or mechanical coordinate measuring machines (CMM) or X-ray computed tomography (CT). The technique described here is advantageous over standard techniques for several reasons. It provides data as the part is being manufactured and reduces the need for a separate geometry inspection step. Part support structure does not interfere with geometry measurement as it would in CMM or CT measurements. The technique also allows for measuring internal geometries not accessible with a CMM. Lastly, validation with respect to other measurement techniques is discussed. The path to incorporate such inspection technologies into final production is also shown.