Seiler Instruments and Manufacturing (St. Louis) is a contract manufacturer, specializing in fi re-control equipment, as well as a distributor of surveying instruments, microscopes and Zeiss planetaria. “Our primary customer, the U.S. military, is very stringent on documentation and product verifi cation. Although not explicitly required, our customers are happy to see sophisticated and automated equipment verifying their product. Some of the instruments are used overseas to support our troops and the product must be accurate,” says Nathan Corliss, assistant quality manager at Seiler Instruments. For Corliss, seeing fi rst-hand the benefi ts of owning an automated coordinate measuring machine (CMM) was a strong motivator in sticking with and purchasing more CMMs from Carl Zeiss (Maple Grove, MN) for their manufacturing plant. Seiler Instruments purchased their fi rst Zeiss CMM, a Vista, in 2006. After experiencing the reliability and accuracy of the Vista, they quickly moved forward in purchasing a Contura G2 with a Vast XXT scanning sensor in 2008. “Carl Zeiss is known for building the fi nest equipment in multiple fi elds and was the obvious choice when entering into the automated CMM arena. The technology and Calypso software were unknown to us until the Vista. Once we saw the benefi ts and advantages, we invested in the more advanced Contura G2 which met our manufacturing needs perfectly,” says Corliss. The Contura G2, with the articulating RDS and XXT, is designed for measuring complex features and parts with multiple angles that require very small styli, which is an ideal CMM for Seiler Instruments. The Zeiss CMMs operate in the middle of an environmentally controlled manufacturing plant, supporting in-process inspection. “We are measuring a variety of different parts from large machined castings to small screw machine style parts. We produce parts for optical assemblies for the U. S. military, primarily fi re control instruments for artillery weapons. The CMMs are used in the middle of the manufacturing plant to aid in the setup and in process inspection of the parts,” says Corliss. ENHANCING THE RELIABILITY Having the correct CMM and software is key to complete accuracy inspection capabilities. “There were things the Contura G2 with the Vast XXT scanning sensor was seeing that couldn’t be detected with our previous inspection capabilities,” Corliss explains. For example, the assembly was having diffi culty with a gear produced from an outside vendor. They determined their process changes were causing the error. “Once they went back to the old process, the scanning characteristics began to show favorable results and the product worked,” Corliss says. It is not uncommon for Seiler Instruments to target tolerances of 0. 0003 inch, which means ensuring the CMM can do the job. On a typical day, a machinist will set up their machining Center and cut a setup piece. Complex parts will be brought to the CMMs for verifi cation and set up adjustments before going into production. When asked how lean manufacturing and measuring instruments from Carl Zeiss fi t into their process, Corliss responds, “Using the CMMs has reduced setup times on several complex parts. Many parts have well over 100 dimensions and would take up to a whole shift to prove out before production could commence. Many parts were reduced from seven hours of surface plate work to one hour total inspection time.” ABOVE AND BEYOND It is important in any industry to maintain accuracy, but when dealing with the U.S. military it is crucial to maintain quantifi able results and reliability on all parts and equipment manufactured. When asked about any surprises or quantifiable results, Corliss says, “The Contura G2 has discovered issues that were difficult to find with standard inspection methods. This has helped improve our processes, our vendors’ processes and the overall quality. Our assembly managers have indicated parts are going together better. The machinists are dedicated to producing high quality parts and have used the information to tweak and adjust processes to achieve better results. The Contura G2 has also validated parts conforming to requirements which were difficult to prove out before.” In the manufacturing industry, it is crucial to learn from quality review inspections and to help others who may also be experiencing similar issues or problems. Seiler Instrument has done a thorough job in both analyzing and learning from their results. “The scanning capabilities of the Contura G2 and Calypso’s ability to create valuable form plots have helped improve our internal and vendor processes. We try to understand why the CMMs are generating the result so we can provide useful feedback to the manufacturing areas,” Corliss points out. “It is important for all CMM programmers and operators to understand how and why the results are generated. I’m not saying you shouldn’t trust your equipment, but understand that a speck of dirt, fi xturing method or bad CNC [computer numerical control] alignment can lead to results that might not be accurate.” Asked what two things best describe his experience using and owning a Carl Zeiss CMM, Corliss states, “Carl Zeiss provides a Calypso forum on their Web site for users to share ideas. At times, Zeiss application engineers periodically check the forum and provide input. Carl Zeiss also hosts annual conferences and a North American user group to solicit customer feedback and provide training opportunities. Overall, the systems have been reliable and provide increased credibility with our customers. It has helped improve our internal and vendor quality.” How should a manufacturer respond to its primary market shrinking? For oil burner and controls maker R.W. Beckett Corp. (North Ridgeville, OH), the answer was to expand into gas burners and controls and signifi cantly step up already good quality. Quality has always been a driving value for the company, which has been family owned and run for more than 70 years. But with more than 1,500 possible unit-build confi gurations, its manual testing procedures had become ineffi cient and inconsistent. “The previous testing process was operator dependant,” explains Quality Manager Vic Turk. “The operator looked at gages and digital meters and judged whether the unit was right. It was labor intensive, less accurate and inconsistent.” In addition, the old electromechanical testers required some manual set up for each new order that ran in the cell. They were often run in a partial by-pass mode, where the green light pass/red light fail feature was disabled for a test feature. In 2005, Beckett moved to automated burner and burner control testing stations as part of a Six Sigma Black Belt project. “Our goal was and is to increase fi rst-pass yield on all tested components and systems,” says Senior Process Engineer Jeff Traczek. THE SOLUTION Sixteen test stands were stationed inline, at the end of the line and at component suppliers. All of Beckett’s testing stations use National Instruments (Schaumburg, IL) LabView. The systems were developed by The RoviSys Co. (Aurora, OH), an independent automation system integrator. RoviSys also engineered a utility that rolls out LabView application and confi guration updates to all the test stands. “But the signifi cant opportunity was the potential to eliminate manual intervention and associated escape of nonconforming material,” says Turk. Upgrading to electronic readouts and data recording promise some improvements. The automated testers can process more complex burner control cycles than with the previous one-size-fi tsall process. Exact pressure anywhere between 90 and 200 psig can be verifi ed accurately without operator infl uence. The new systems have enabled Beckett to steadily expand and improve the rigor of testing and verifying additional functions and features. With the new test stands, each burner automatically goes through a complete and verifi ed cycle and is left in a ready-to-ship state. “Now once the burner completes a test cycle,” Turk says, “measured values are verifi ed against parameters for the specifi c unit before the approval label is generated on line. This provides positive mistake-proof verifi cation of burner performance and quality.” Beckett runs some test stations standalone and others tied into the plant network and enterprise resource planning (ERP) system. Work orders are pushed down to the end-of-line stations. The system locates the test criteria for that model number. The new systems sample and collect dozen of input/output (I/O) points at every step including voltages, currents and pressures. When a unit passes fi nal testing, the test stand generates a serial number and automatically reports to the plant system. Beckett tests 100% of units and the test systems will print a label only if the unit passes, Traczek says. “There are certain tests that must be performed for UL, like HI-pot. Our test stations ensure these tests are being done. The Unit passes or it doesn’t. There are no judgment calls.” Turk says his quality department is digging into the data. “Using thousands of sets of burner data, we can continue to improve test parameters to avoid missed operations, incorrect settings and other factors. We have several such projects in process.” Traczek says his production team regularly reviews the data for trends. Their goal is to prevent defective units from reaching fi nal testing. “We can identify problem areas and why things are failing. We look for the top 10 issues at any given time and go hammer on those,” Traczek says. If, for example, an unexpected number of blower motors are causing systems to fail, they want to know why. “We go to the source to fi gure that out.” Turk says the testing program “has improved the consistency and reliability of fi nished burners for our customers with more complex testing demands without any increase in the tester cycles.” Traczek adds, “If you are involved in this industry in anyway, you know Beckett has always been highly motivated by quality and reputation. We take quality very seriously.”
Published by QualityMagazine. View All Articles.
This page can be found at http://digital.bnpmedia.com/article/Case+Studies/380952/36978/article.html.