Striving for Consistency (continued) optimized. One process, which originally took 33.4 seconds, was reduced to 14.4 seconds. Another process was shortened from 30.8 seconds to 19.2 seconds. Sauer-Danfoss officials found that after optimizing some of their Easley machines with the tools, five revamped machines saved a total of 510 production hours annually. Overall maintenance costs for running the five machines were reduced by $37,270. “Our quality has greatly improved, and we increased capacity by almost 5 weeks,” Bryant said. Past due shipments, scrap and cutting time were reduced. The plant increased capacity by 22 percent, said Duvall. “As a result, we no longer needed to make a $1.2 million capital investment in two machines. Our total savings was about $2 million.” The Easley plant also reduced its overall operation time from 24-7 to 24 hours a day, 5 days per week. Seven machines running 5 days a week now have a higher capacity than nine machines running 6 days per week did previously. The facility now always meets demand. The tools proven at Easley will be implemented at other Sauer-Danfoss manufacturing facilities around the world. “By having established the process, they know what the cost per unit is, based on the history,” Mann said. “Quality and cost are controlled on a global level; they know their quality will be predictable.” While Bryant initially was leery of working with just one company on tooling solutions for the Easley machines, he believes now that a one-source approach is advantageous. “When you have one source, you get better support. You’re not dealing with several people at different companies,” Bryant said. In an age when outsourcing is a fact of life for many companies, the custom tools helped keep the work in-house and make Sauer-Danfoss more competitive. Duvall said it’s critical that manufacturers take advantage of all technical knowledge to keep business in North America. “We can be low-cost if we do the tooling and machining properly,” he said. “A low-priced tool isn’t always the low-cost solution.” —Jonathan Barnes, a freelance writer based in Pittsburgh in the overlap area between the central and peripheral sections where notching originates, especially when drilling aggressively. “Most ductile iron customers are just trying to drill ductile, like anything else, as fast as they can so drilling is done at elevated speeds and feeds,” he said. Cool Down Coatings can resist the high temperatures generated when running at high drilling parameters. Titanium aluminum nitride is particularly effective. “It gives a very good resistance to the heat,” Cole said. Allied Machine coats its spade drills and replaceable-tip drills for drilling ductile iron with the company’s proprietary AM200 coating, which resists heat and wear and was developed specifically for drilling, according to Porter. “It has good lubricity properties as well, so it prevents material adhesion,” he said, adding that the coating’s thermal characteristics allow running at spindle speeds 20 percent faster than when applying TiAlN-coated drills. Guhring offers its PVD Firex coating on the Ratio drills, which Hellinger described as a combination of TiN and TiAlN in a multilayer structure to achieve a reference hardness of more than 90 HRC and an oxidation of the coating up to 1,470° F, which is 300° F higher than a monolayer TiN coating. Another option is the C7 Plus nanocomposite coating that Unimerco offers. “It’s like AlTiN but much harder, so it helps the tool hold up under the abrasive wear condition,” said Stead. The coating’s AlTiN grains are embedded in an amorphous matrix of silicon nitride. According to the company, the coating maintains stability up to 1,100° C before its grain boundaries begin to oxidize and the coating’s structure decomposes. It has a hardness of 45 GPa. Some coatings enable dry machining, but coolant is desirable when drilling ductile iron to help evacuate the material’s small, curled chips. Flood coolant
Download PDF file
Archive