Shop Solutions: Multipallet HMC Builds KanBan Performance
Kenlee Precision Corp. (Baltimore, MD) knows very well the demands that blanket order contracts for multiple parts and different customers can place on a manufacturing operation. “Every week we release a myriad of parts for customers that require reduced lead times, exacting quantities and specifications, on-time delivery and of course, 100% quality,” said Kenneth Lewis Sr., owner of Kenlee Precision.
“An operation as complex as this requires machines and systems with the utmost performance, precision and reliability or you’re not in the game,” said Lewis. Facing capacity issues as well as these well-known challenges, Lewis sought a solution to meet the growing needs of his company’s KanBan system and found the answer in a six-pallet KIWA horizontal machining center from Methods Machine Tools Inc. (Sudbury, MA).
Kenlee has 77 employees at their 50,000 ft2 (4645 m2) facility in Baltimore, currently operates two nine-hour shifts and is ISO 9001 certified. With a mantra of “quality without compromise,” Kenlee has progressed in large part due to their commitment to strategic capital investment in state-of-the-art machining capabilities in order to satisfy customer needs. Since 1969, the company has focused on the custom manufacturing of precision components and finished assemblies in medical, semiconductor, electronic, military, transportation and other markets.
Early on, Lewis positioned the company as a “one-stop shop.” Services include CNC machining as well as sheetmetal fabrication and electro-mechanical assembly, and even testing and finishing phases. “We are a customer-driven supplier with a can-do attitude,” said Lewis. “We always say, ‘if you can’t measure it, you can’t make it’. The best way to compete is by staying with the latest cutting-edge technology.”
Currently, Kenlee has 50 state-of-the-art, turning, vertical and horizontal machining centers including 10 new machines that were added over the last four years, in addition to three Zeiss coordinate measuring machines. The shop has a full range of equipment, from basic machines and cells up to machines with high-end jig borer capability. When a new customer need arises, Kenlee often looks to their long-standing machine tool partner Methods Machine Tools for technology expertise and solutions. Kenlee has 12 machines from Methods, including machines from various lines such as FANUC RoboDrill and Feeler VMCs and a Nakamura-Tome turning center.
Multipallet machining lies at the heart of Kenlee’s high-mix order system. “A good example is a customer with a blanket order for 100 parts, the same parts per month, 1200 parts per year,” said Lewis. “We probably have 300 different parts tied to blanket order contracts. Parts are manufactured and inventoried in two buckets, limited to 200 minimum or 500 maximum per bucket. Then parts are drawn each week on specific days to keep a constant flow through the plant. This is very demanding. We have schedules down to a science, but it all requires highly reliable, multipallet machining and automation” said Lewis.
To maintain the necessary order pace and ensure a steady product flow, Lewis sought Methods Machine Tools’ expertise for recommendations on the best multipallet machining solution. “We wanted a variety of jobs to be pre-set in advance, while also having the flexibility of open pallets available, without tearing down one setup to do another job. By applying this approach, we are always ready to go, with the ability to start, stop, or move to another job at any point in time. And multipallets also allow unmanned operation for profitable, productive lights-out manufacturing,” said Lewis.
Methods recommended a KIWA KH-45 six-pallet HMC which Lewis added to Kenlee’s machine arsenal in late 2013. The 40-taper, 400-mm pallet KIWA increased the number of Kenlee’s HMCs to 13, an unlucky number for some but not to Lewis. “We’ve had great success with the KH-45, not only for its speed and fast tool-change feature which is very impressive, but also for its accuracy and the large work envelope. The larger travels and 15,000 rpm are ideal for much of our aluminum and steel work,” said Lewis.
Kenlee wasted little time putting their new KIWA KH-45 to the test, running complex parts in multipallet setups. Their employees gave the machine high marks. Don Wheeler, Kenlee setup manager, said: “The KIWA can hold super-tight tolerances all day of up to ±0.0005" [0.013 mm] in holes and contours of challenging parts. It is routinely capable of 32 Ra finishes on contours and excels in holes and boring with the circular interpolation features. We’re running parts in 1044 cold-rolled steel and also aluminum. Even though we’ve been very aggressive with the machine, the speed and performance are great even at feed rates of 200 ipm [5 m/min] in steels.”
Lonnie Bray, Kenlee’s manufacturing manager, agreed: “The KH-45 rapids are very impressive. We are able to easily get in and out of a job in a shift and a half and increase our supply of parts much faster. In the same time required, we noticed the KIWA yielding 32 parts on one particular job compared to 25 parts on our next best HMC.”
Both Bray and Wheeler are also pleased with the Rigid Big Plus spindle which enables increased speeds, improved finishes, less chatter and other features that make machining smoother. “KIWA put a lot into the KH-45 design, from a 200 block look-ahead for performance to the clever time-and-hassle-saving chip disposal system, to the user-friendly FANUC control with simple, powerful editing and recovery features. They really thought things through,” said Bray.
Kenlee never hesitated on purchasing the KIWA because they have always relied on Methods’ expertise and support. “If Methods is behind KIWA, then we are as well—100%,” said Lewis. “Methods has always believed in us and we believe in them. Since the KH-45 was installed, which went very quickly without a hitch, we’ve seen an average production time savings of 20%, not to mention increased throughput, tooling and pallet flexibility. At the end of the day [or night] in KanBan operation, reliability is the ultimate measure. In three months, the KIWA has never stopped running,” said Lewis. ME
For more information from Methods Machine Tools Inc., go to www.methodsmachine.com, or phone 978-443-5388.
This article was first published in the July 2014 edition of Manufacturing Engineering magazine. Click here for PDF.
Published Date : 7/1/2014