Metrology: NVision HandHeld Scanner Drastically Cuts Engine Modeling Time

(NVision: Coppell, TX) -- Cameron Compression Systems used NVision HandHeld laser scanners to produce a solid model of an existing large engine in one-tenth of the time that would have been required using conventional methods.

“It would have taken several years to re-engineer the large diesel engine block pan and heads using a coordinate measuring machine (CMM),” says Greg Obets, manager of engineering systems for Cameron. “Instead we scanned these components, converted the resulting point cloud into a solid model, and made the tweaks necessary to prepare them for production in only two months.”

Cameron Compression Systems provides reciprocating and centrifugal compression products, systems, and services to oil, gas, and process industries. The company also previously built a line of 12 to 16 cylinder two-stroke diesel engines to power its compressors. The company discontinued these engines about 10 years ago but customers have been asking Cameron to bring them back and recently the company agreed.

Engine parts being scanned at Cameron

The engines were designed using paper drafting methods and several of the paper drawings had disappeared. The engines worked well so there was no need to redesign them from scratch. “What we needed was a way to reverse engineer the existing engines to create solid models that could serve as the basis for manufacturing,” Obets says. “It would have very difficult to reverse engineer these parts using a CMM. Collecting one point at a time with a CMM, we would only have been able to capture a rough outline of the geometry. So we would have had to redesign most of the details from scratch.”

Cameron decided to investigate laser scanning and looked at several different scanners. The company selected the NVision HandHeld scanner because of the 8-inch laser stripe width, which is four times faster than small-stripe technology. The HandHeld scanner is a portable device that is capable of capturing 3-D geometry from components of virtually any size. It is attached to a mechanical arm that moves about the object, freeing the user to capture data rapidly and with a high degree of resolution. An optional tripod provides complete portability in the field. Intuitive software allows real-time rendering, full model editing, polygon reduction, and data output to all standard 3-D packages.

“NVision developed a training program specifically for our people, tailored to our unique parts,” Obets says. “Before the training ended, they had begun scanning the parts. There are many closed internal passages so we scanned the outside first and then cut away the exterior as needed to expose the interior. It took only two weeks to completely scan all three parts.”

Cameron used the integrated HandHeld software to reassemble the point clouds in a single file for each component. Reference points included in the original scans made it easy to re-assemble the different point clouds in their proper relationship. Then the company used XOR software to convert the point clouds to a solid model.

Screen capture of scanned engine pan

“We imported the solid model into Siemens PLM NX software where we tweaked a few things, such as thinning out or beefing up surfaces,” Obets says. “In only two months, we were ready to turn the solid models and drawings over to manufacturing. The NVision HandHeld scanner yielded enormous time-savings for us on this project.”

For more information, visit www.nvision3d.com.

About The Author

NVision Inc.

Established in 1990, NVision Inc. provides customers with the highest accuracy noncontact optical measurement systems and services for reverse engineering and inspection. Focusing its expertise on the aerospace, power generation, and oil/gas industries, NVision provides both contract scanning services and systems sales to companies throughout North America. Its team of engineers provides customers with an unmatchable level of experience and is able to advise and assist with the most difficult engineering challenges.