Technology on Tour: The Great American Metrology Road Trip
Jeff Moore loaded up his Dodge Ram Van and set out on a road trip across North America. Mojave. Bryce. Zion. Carlsbad. Mesa Verde. From Coronado Island to Ontario, Canada…he zig zagged across the country to visit his foundry friends. In addition to hiking boots and binoculars, Jeff loaded his Dodge van with an automated metrology inspection system, dreams of his own company, and a mission to educate aerospace casting manufacturers on the future of First Article Inspection (FAI).
Prior to his epic road trip, Jeff spent more than three decades in the castings business as a producibility engineer and senior quality assurance manager, including jobs with aerospace industry giants Hamilton Sundstrand and Pratt & Whitney. As a result, he recognized the shortcomings of casting inspection methods and set out to improve it.
Traditional coordinate measuring machines (CMMs) and mechanical inspection systems using height gauges, surface plates, and rotary tables have been the primary inspection tools for cast parts. These tools are slow and subject to human error or deviation. Due to the tediousness, many casting companies restrict measurement to first article inspection.
While traditional methods met ISO 17025 regulations and gave a good idea of how the first part met requirements, it didn’t provide feedback on all parts cast afterwards. It also led to a higher potential for errors and scrap, which is especially expensive for aircraft components such as engine front frames, pumps, and gearboxes. Moreover, deviations aren’t immediately obvious.
The Digital Way To address these problems, Jeff started his own business, The Layout Source, in 2015 to create a better option using 3D automated “blue light” scanning and traditional methods. Blue light technology recognizes part contours by triangulating two camera lenses and a beam of light that projects a pattern on the part surface. Software then compiles and converts millions of images into a point cloud, creating a 3D representation. Blue light is more precise than white light, and it has shorter wavelength which works better with reflective surfaces.
Jeff knew skeptics would resist changing traditional inspection methods, so he had the unusual idea to take his show on the road. In order to equip the Dodge van, Jeff contacted Paul Oberle, director of business development for 3D Infotech, a metrology 3D systems integrator.
Based on Jeff’s requirements for mobility, speed, and accuracy, 3D Infotech designed a self-contained system that fits a 2 ft. by 4 ft. table, calling it the Universal Metrology Automation (UMA) Smart Station.
The UMA features a FARO Cobalt Array Imager affixed to a Universal Robots UR5 collaborative robotic arm, a rotary table, a laptop workstation, and software for 3D image analysis. Between the robot and the rotary table, the system measures the casting from every angle.
“We designed the UMA specifically for the confined space in the van but without sacrificing performance,” Oberle said. “The software and touchscreen provide an easy user experience, so operators avoid the complexities of robot control programming. The system scans 1.3 million measurements per second and is accurate to 0.0009 in., which is ideal for cast parts.”
Metrology on Tour At each location on his tour, Jeff demonstrated that he could reduce inspection times to a few minutes. This method provides a 3D image of the casting inspection result thus proving conformance or providing a basis for rework instructions.
With the digital approach, manufacturers can overlay scan results on a CAD model. A color map can show how every single point on the part relates to where it’s supposed to be on the model. The departure from nominal is explicit by a color scale. Production personnel can use that data to calculate tool offsets for machining that part, as well as compile SPC data on key features that monitor process variation throughout their very complex manufacturing system.
“Costs increase if a part goes to the next step and it gets rejected for a defect that could have been detected earlier,” says Jeff. “When a part gets scrapped at an engine test in a just-in-time world, that’s a major cost.”
Farewell Tour After two years of touring, Jeff retired the van and put all his energy into working out of his shop located in Alpine, Calif., about 30 miles east of San Diego.
“When I was on the road, I showed the benefits of digital solutions for first article inspection to be correlated to production parts.” Jeff said. He also discussed hybrid first article inspection (FAI) methods. Hybrid uses exterior part scanning with saw or mill cuts to access internal features. This is called a hybrid approach because it often uses mechanical methods to inspect hard-to-reach internal areas that scanning will not reach. It is destructive, for FAI only, but having a scan system robust enough for the production floor is the most cost-competitive volume production approach. Computed Tomography also offers a non-destructive way to attain complete part data, but that is typically for FAI only.
Moore says there’s still more education to be done. He wants to show the value of scanning every single part that gets shipped to prove that the part is good, and he remains a tireless advocate for more structured, data-driven metrology methods. His challenge is that the industry is moving in many directions because each company has its own, product-specific inspection requirements, budgets, and experience with digital methods. Customers weigh into this technology advancement, as well.
“What I’m trying to do is pair their internal experience with digital inspection resources and metrology solutions from companies they respect, such as 3DInfoTech, FARO, and Universal Robots,” says Jeff. “My visit with the portable automated digital equipment invited a welcome rapport, especially because it came from a trusted source. I was not trying to sell them equipment, but rather to advance their knowledge of digital inspection methods.”
Thanks to the mobile metrology road show, aerospace casting companies know they can get an unbiased opinion— based on deep quality assurance and engineering expertise— from Jeff at The Layout Source.