By James Sawyer
Call it what you will—metrology, inspection and measurement, or quality assurance (as IMTS labels it)—the segment of manufacturing that is focused on accuracy and repeatability is one driven by innovation.
As Denis Zayia, national sales/marketing manager for Renishaw Inc. (Hoffman Estates, IL), sees it, "The four key trends driving this innovation are first, a better understanding that all aspects of process control, rather than postprocess part inspection, should be the first consideration. There is greater focus on weeding out process variables upstream, before they affect downstream inspection data. Acceptable parts are a function of:
- Keeping machines calibrated and ‘process capable’—able to produce good parts.
- Ensuring parts and tools are set correctly
- Checking parts in-cycle, etc.
"Controlling process variation allows for consistent, automated and productive machining by being in position to identify the source of variation and then rectify the problem.
"Second, metrology is also being driven by management’s focus on increasing throughput from existing assets, increasing the use of automation and reducing human intervention.
"Next, velocity—customers are concerned with how fast inspection data can be gathered and evaluated to make timely adjustments to keep the process in control. This also means more mid-cycle inspection of parts while still fixtured on the machine or performing some level of postprocess inspection on the machine itself.
"Customers are concerned with how fast inspection data can be gathered and evaluated to make timely adjustments to keep the process in control."
"Finally, data density—more data points mean more accurate form measurements. The more points taken, the more information one has about the part and its features."
Contact vs. Noncontact Measurement
While one innovation, noncontact measurement, is seen by some to be the quickest way to generate a large number of data points, Zayia does not agree: "One can achieve this with high-speed five-axis CMM inspection as well. Revo and other motorized five-axis CMM heads do accommodate noncontact sensors. However, many issues remain with noncontact besides accuracy, such as reflectivity of the surface, access to features, etc."
Nor does Zayia see noncontact measurement putting contact measurement out to pasture any time soon.
"Noncontact measurement," he says, "has too many complexities to make it as broadly applicable [as contact]. Noncontact is still considered niche and has yet to match the accuracy capability of contact sensors."
"Renishaw’s exhibit at IMTS," Zayia says, "will show the company’s integrated capability as a full-scope solution provider for process control, offering technologies that ensure machine capability, correct workpiece setup, in-process control, and postprocess part checking."
Marposs Corp. (Auburn Hills, MI) also feels that contact measurement has a lot going for it.
"There are still many situations that require contact gaging," says product manager Frank Powell. "For example, contact is still the best in the machine measurements where the environment is harsh. Contact gages have larger clearances between the gage reference and the workpiece that an air gage cannot tolerate, and coolant and chips are cleaned away by the contact gage in applications where an optical gage cannot operate."
According to Gary Sicheneder, Marposs’ manager of business development, "One of the major focuses at IMTS 2012 is our Marposs Monitoring Systems [MMS] initiative that combines products from several of our divisions. MMS integrates hardware, software and sensors for purposes of monitoring and controlling machine tools and processes to provide the greatest amount of productivity."
MicroRidge Systems Inc. (Sunriver, OR) has perhaps a bit of a different perspective on innovations in quality assurance. The company designs and manufactures products that can directly or wirelessly connect any combination of digital gages and multiple RS-232 devices to a PC. The configurability of the gage interface and wireless products allow them to be used with any statistical process control or data acquisition software.
"Over the last four years," says John Schuldt, president of MicroRidge, "we have seen innovation driven by the availability of appropriate wireless technology including the advent of low-cost, short-range wireless technologies. We are seeing this wireless technology being built into or available in hand-held computers.
"Since we introduced our first-generation wireless in 2006, we have seen wireless grow to well over half of our total sales. We expect the growth of wireless systems and new wireless applications to continue at a fairly rapid rate for the foreseeable future."
At IMTS, MicroRidge will be introducing RoverBase wireless handheld. "RoverBase," Schuldt says, "provides complete mobility for measurement collection and analysis. Our focus at the show will be demonstrating how wireless measurement collection is actually a more cost-effective solution than using a hard-wired system in many applications."
According to Michael Creney, vision and optics manager, Mitutoyo America Corp. (Aurora, IL), the high functionality of optics, cameras and computer processing systems, "has allowed Mitutoyo to increase their speed and performance in the stroboscopic measurement arena by utilizing asynchronous data-processing techniques. The incorporation of interferometry, chromatic point sensors, and optical methods offer customers a broader based capability than ever before.
What the Customer Wants
"Our most recent developments in both hardware and software continue, but our customers are particularly interested in ease of use."
Mitutoyo will be showing its latest developments, including surface roughness testers such as its Skid Type SJ-310 and Skidless SJ-411/412.
In his discussions with customers, Chris Grow, VP of marketing for Carl Zeiss North America (Maple Grove, MN), finds that their concerns are towards "increased productivity and throughput on existing equipment and on future systems. They need faster measuring times from start to finish—with software enhancements and options, advanced clamping and workholding systems—anything that allows them to get the right information, faster."
While "there is potential benefit to upgrading an existing machine," he notes, "you will always get better performance with a new system."
A Push for Productivity
Going forward, Grow believes there’s "going to be a continued push in the direction of productivity on the shop floor. CMMs continue to get better in dealing with vibration resistance, temperature extremes, and providing faster measuring speeds." Carl Zeiss will introduce the O-Inspect 322 multiscanner, which combines contact scanning and optical measuring at IMTS 2012.
Hexagon Metrology Inc. (North Kingston, RI) will feature innovations in measurement automation at IMTS. The spotlight will be on the new Cognitens WLS400A for automated measurement applications and PC-DMIS 2012 inspection software. The company will also demonstrate recently released products, including Romer portable arms, Optiv Vision 321, Sheffield and Brown & Sharpe 4.5.4 SF CMMs, and PC-DMIS software.
Real-Time In-Process Metrology
"We are excited to be presenting our automated solutions at IMTS in 2012," says Norbert Hanke, president of Hexagon Metrology worldwide. "These systems, which incorporate our sensors on industrial robots, are now in the mainstream for automotive and aerospace manufacturing, and are allowing much greater speed and point density than previous solutions. The era of real-time in-process metrology is upon us."
Hexagon places a great deal of emphasis on innovation. "The biggest threat we are facing in technology development right now," notes Angus Taylor, president of Hexagon Metrology North America, "is component lifecycles." Hexagon, he says, puts a lot of effort into developing existing and new technologies because it does not want to be leapfrogged by the competition in an era when technology is rapidly changing. ME
This article was first published in the August 2012 edition of Manufacturing Engineering magazine. Click here for PDF.