In a fiercely competitive global economy, quality matters now more than ever. ESCO Corp., a designer, manufacturer, and distributor of products for mining, construction, power generation, and aerospace applications, wanted to streamline quality control for new product development based on metrology hardware and software that could provide high usability, portability, and on-demand inspection.
ESCO’s Dimensional/Gage Department ensures product quality in two ways. One way is physical gaging, which is fixturing on the shop floor that is used by the manufacturing department to ensure a product is built to specifications. The fixturing is developed, designed, and built in-house and distributed to all facilities. The other way is soft gaging, which is the use of software, coordinate measuring machines (CMMs), and CMM programming to inspect product in a process-controlled environment for the rigors of new product development.
The department uses a traditional bridge Brown & Sharpe CMM to inspect many parts automatically using prewritten programs. But the company found itself in the need of a solution that could measure very large parts that fall outside the CMM's measurement envelope.
"We needed to add a new tool for in-place measurement of our large parts that required no up-front programming,” said Taylor Finley, Dimensional/Gage Engineer. “Many engineers working on new product development need to do a quick inspection by themselves without having to go through an operator or an engineer to program a one-time inspection. We wanted a system that an engineer with little or no experience could learn and operate quickly. It takes a lot of metrology experience to run a CMM and program CMM software, taking one to two years to train the operator. Our parts are becoming more and more complex. We are not dealing with simple surfaces anymore but intricate contours that create a challenge to measure and verify our parts."
The "self-serve" solution they settled upon was the Romer ScanShark V5 laser scanning system comprised of a seven-axis Infinite 2.0 portable CMM, a ScanShark laser scanning probe, PolyWorks software, and a computer. The combination of articulating arm measurement with laser scanning enables maximum surface inspection of any large workpiece. The noncontact laser scanner acquires more than 458,000 points per second for detailed inspection of both geometric and surface features in a fraction of the time of probes with lesser capabilities. The 9-ft (2.7-m) seven-axis scanning arm has a hemispherical measuring envelope of 18 ft (5.5 m) and operates like a human arm. Its Zero-G counterbalance offsets the weight of the carbon-fiber arm and scanner for one-handed operation from any position in the arm's reach, above and below the midline. The arm's infinite rotation of the principal axes enables ESCO users to inspect hard-to-reach areas on their parts. The configuration also allows for point data acquisition with contact probes when needed, without having to swap the laser scanner for a contact probe.
"Speed to market is one of our biggest pushes," said Alex Rizzuti, Lead Engineer for the Dimensional/Gage Department. "We cannot take five or six years to design a product. Giving the engineer a tool that would allow them to spot check their products immediately appealed to the group. Every one of our engineered products has a dedicated engineer and group. All quality work funnels through the Dimensional/Gage Department, and we program all CMMs for our facilities worldwide. For continuous improvement and shortening time to market, work simply cannot sit around in the queue. So the self-serve model without the programming up front is key to our effort. An engineer needing to verify a part can book the scanner when they need it and acquire their data in a day."
"The Romer/PolyWorks solution met our classification of a self-serve system based on the fact that with a small amount of training, any engineer or manufacturing person can check out the device when they need it," said Finley. "The range of the scanner arm gives us the ability to capture complex angles and work around fixturing, which eliminates multiple setups. The arm's elbows and wrists make it easy for us to set up a part and move all the way around it. The PolyWorks software enables us to post-process point-cloud data, stitch surfaces, align data, and do a complete inspection of a part using the basic analysis tools in the software, including color mapping to tolerances showing what is in spec or out of spec," said Finley.
Rizzuti says that most of the off-the-shelf features of the PolyWorks software worked well for their applications. "The best part of the software is that we can customize the desktop for our engineers. Removing tools from the menu that we are not using helps us streamline the self-serve model. We give our engineers exactly what they need for the job at hand, so there is no veering off the path."
Dave Armstrong, Product Manager, Hexagon Metrology, wrote this article for SAE Off-Highway Engineering.