CMM Provides 213% Improvement When Cotta Transmission Co. LLC (Beloit, WI) determined their old coordinate measuring machine (CMM) was beyond its useful life, Xspect Solutions (Wixom, MI) provided a proposal that combined a new Wenzel bridge-type CMM equipped with OpenDMIS software and a level of basic gear measuring capability that optimized Cotta’s current needs. Cotta Transmission Co. LLC, an industrial and specialty transmission manufacturer, purchased a new Wenzel LH 12.30.10 CMM, equipped with OpenDMIS software with a special gear checking module. Todd Wells, Cotta quality manager, explains, “When I joined Cotta as the quality manager, the organization was already extremely discontent with their current CMM equipment. Actually, the CMM operators were using the DCC [direct computer control] CMM as a manual machine because of fears it would crash, and they would often reinspect product multiple times because they had little confi dence in the results. A team was assembled to rectify the situation. The 1970s CMM that we were using had been rebuilt once already, and when we conducted an accuracy study it was obvious it was not repeatable any more.” For example, Cotta performed one study where the same part was inspected several times on a program that was written to run in automatic mode. The measurement results varied more than 220% from the required design tolerance. With this new knowledge of the CMM’s inability to repeat, the team mandated subcontracted CMM inspection for specifi c parts with tolerances too critical for the old CMM until a new CMM could be purchased. They estimated that their work level would require an expenditure of at least $100,000 during the next 12 months to accommodate subcontracting to an outside CMM service. Cotta needed a new CMM to meet customer needs and to continue to deliver a quality product on time. They wanted to purchase a new Wenzel CMM, and liked OpenDMIS software, but they were not confi dent their budget or timing requirements would permit it. They contacted Xspect Solutions, Wenzel’s operation in North America and discussed the situation with Nick Moceri, Xspect’s regional sales manager, and Keith Mills, president. POTENTIAL SOLUTION “After listening carefully, Xspect Solutions developed a program for us that took advantage of a combination of circumstances that ultimately gave us the machine we wanted within our budgeted cost, delivered on time,” Wells says, “which actually ended up being ahead of time.” Wenzel CMMs have precision manufactured impala black granite bases and bridges, precision and hemisphericalcylindrical air bearings, and standard Renishaw probing systems with volumetric accuracy of 2.5 microns. “As a result, Wenzel machines are typically not the cheapest CMM on the spreadsheet,” Mills says. “However, for Cotta, we were able to put together a proposal that involved a special CMM that we had loaned to another customer while waiting for a larger Wenzel machine to be built for them. Because we already had the loaner CMM being returned, we were able to make the necessary arrangements to tie in the logistics and machine exchange, as well as customize the CMM to meet the Cotta accessories and software needs. The new machine and software would be able to handle the entire range of products Cotta is producing.” Wells adds, “We had been looking at machines equivalent in size to the Wenzel 12.30.10 that were 1995 vintage. We ended up with a 2008 Wenzel structure with new controller, probing, PC and software. In addition, we received software that included the gear measuring module, allowing us to develop basic gear data right on our CMM. This also allowed us to move our small gear measuring machine out of the CMM room and into a location closer to our gear manufacturing department.” SUCCESSFUL INSTALLATION Within a week of installation, Cotta technicians had already successfully created part programs from computeraided design (CAD) fi les and inspected a number of part designs. They duplicated the study conducted on the old CMM on the new Wenzel and the results showed a 213% improvement in the measurement variation. In addition, their CMM operators liked the ability to preview machine movement with the OpenDMIS software. They also purchased an offl ine OpenDMIS software seat that allows them to develop new inspection programs while the machine is being used. The decision to purchase this additional seat was the result of some feedback obtained from another Xspect Solutions’ customer who wished they had an offl ine software seat. Also, as part of their purchase package, Cotta received four days of training for three of their people. “We did another interesting thing,” Wells says. “Because our old CMM was not worth rebuilding again, we decided to dismantle it and use the granite base and bridge and turn them into inspection surface plates. We had them lapped and calibrated and have them in use again in our shop. Xspect Solutions also offered to take our old Renishaw PH9 probe in trade for the new PH10M that was supplied with the CMM, and also gave us a useful styli change rack that mounts directly on the base plate.” The Wenzel LH 12.30.10 is a bridgetype CMM with a measuring envelope of 1,200 by 3,000 by 1,000 millimeters, which provides adequate table capacity for some of the larger transfer cases that Cotta produces. With this machine design the Y-axis guideway is machined directly into the granite base plate, providing long-term accuracy and stability. The machine has a maximum 3-D measuring speed of 700 millimeters per second with maximum acceleration of 2,000 millmeters/second2. It is equipped with a Renishaw PH10M probing system and a HT400 teach pedant that eliminates the keyboard interaction necessary with conventional CMM teach pendants. Wells concludes, “The installation and calibration of the Wenzel CMM was well within our needed time frame, which was notable because the machine was confi gured when the installation was taking place. Communication with Xspect Solutions’ administrative and technical personnel has been seamless, including the coordination of any of the loose ends that normally occur with a project like this. We were even allowed to tour one of Wenzel’s other customers to get familiar with the same CMM prior to the arrival of our new machine. This has been a very successful supplier/ customer project.” Reduce Reverse Engineering Time Astro Machine Works (AMW, Ephrata, PA) specializes in building custom machinery and equipment, as well as machining precision parts to exact customer specifi cations. They also perform machine repair, welding and metal fabrication, and reverse engineering. The company serves top regional and national companies such as GE, Hershey, DuPont, Bayer and the U.S. government, and industries such as aerospace, general manufacturing, medical, pharmaceutical, food processing and energy. Each of Astro Machine’s different applications presents unique challenges, but their work in reverse engineering obsolete OEM parts was a particular challenge. These parts range in size from 1-inch cubes through 48-inch cubes and larger. Previously, AMW used older methods such as hand gages, calipers, micrometers and protractors. These options proved to be ineffective since many of these OEM parts are very complicated, with an array of blended radii and compound angles. Manual tools, even when used carefully, resulted in hit-or-miss accuracy. SOLUTION AMW searched for a better solution for their metrology needs. They considered a conventional fi xed coordinate measuring machine (CMM), but found a more versatile solution matched their needs: the 8-foot FaroArm Platinum. This tool serves both in-process and fi nal inspection functions, as well as reverse engineering. It can be taken directly onto the assembly fl oor and secured to custom machine assemblies while manufacturing is still in-process. This provides an integral inspection device that can aid in alignment and part position during various stages of assembly. Any inconsistencies associated with manual reverse engineering have been eliminated and AMW’s work is now completely accurate, while increasing productivity. What previously took hours of work has been reduced to approximately one-tenth the time. Many of the parts they reverse engineered manually in the past are now being done again so as to bring the accuracy up to their new Faro standards. RETURN ON INVESTMENT The greatest value to Astro Machine with the FaroArm has been the massive time reduction in reverse engineering obsolete OEM parts. In many cases, the time has been reduced ten fold. “Prior to our Faro solution, it was not uncommon for our more sophisticated parts to take 8 to 50 hours to reverse engineer,” says Designer Dan Hughes. “This time has now been reduced to 30 minutes to 5 hours.” A reduction in time is a reduction in cost, which makes AMW more valuable to their customers. Astro Machine invests heavily in its technology, and advancements are the cornerstone of their continuous improvement strategies. Not surprisingly then, the FaroArm was well accepted. The implementation process was easy and the learning curve was not steep with the user friendly software. AMW uses their FaroArm on a regular basis for inspection purposes and at the outset of projects for reverse engineering. With the gained versatility of the FaroArm, no part is outside their capabilities.
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