Bridge to higher productivity

END USER: Natoma Corp., (785) 877-3529, www.natomacorp.com.
CHALLENGE: Reduce workload on Swiss-style and mill/turn machines.
SOLUTION: A machine tool that bridges the gap between Swiss-style and multitask machines.
SOLUTION PROVIDER: Eurotech, (352) 799-5223, www.eurotechelite.com.

Every parts manufacturer welcomes the addition of a major customer. Natoma Corp. is no exception, but that good news did require the company to invest in new machining equipment to reduce the excessive workload the new business put on its Swiss-style machines and mill/turn machines. “We picked up a new customer last fall that has basically doubled the workload in our lathe department,” said Brandon Peterson, shop manager for Natoma.

Located in Norton, Kan., about an hour’s drive from Lebanon, Kan., the geographic center of the U.S., Natoma was founded in 1982 and produces parts for numerous industries, including aerospace, defense, medical and environmental, in its 70,000-sq.-ft. (21,336-sq.-m) facility.

Eurotech video report offers a glimpse into the workings of its Polygim Zeit Model 42 SLY2-B CNC screw machine.

The contract manufacturer wanted to increase its capacity for completing parts in a single setup and initially considered buying two machines: one Swiss-style and one multitask. However, the search soon shifted to locating a machine that could bridge the gap between the two. “We started looking at machines that have the interchangeable spindle with guide bushing and standard chucking options,” Peterson said.

That would enable the shop to produce its shaft-oriented product line—such as those with long bearing diameters and fine surface finish requirements, and more complex parts that require a larger bar size—on one machine.

After considering several different machines, Natoma selected the Polygim Zeit Model 42 SLY2-B CNC screw machine from Eurotech, Brooksville, Fla. The major factors in the decision were the machine’s fully programmable B-axis on the main and sub spindles and its ability to produce a Swiss-style part with a bar capacity of 15⁄8 " (41.275mm), according to Peterson. “We’re able to take parts from both worlds and make them work,” Peterson said. “With the addition of the proprietary B-axis feature, we greatly increased our capacity.” For instance, the company can produce parts with angled holes or milled features without a secondary setup. “The machine gives us an additional outlet for parts that we may not have quoted in the past.”

(Left to right): Brandon Peterson, shop manager; Travis Chisham, lathe foreman; and Jake Stalder, lead Eurotech setup technician, with Natoma’s Polygim Zeit Model 42 SLY2-B CNC screw machine from Eurotech. Image courtesy Natoma.

He added that changing from spindle and guide bushing to fixed collet or vice versa is “relatively painless” and takes about 30 minutes. “It gives us the capacity to take some parts that we run in a Swiss-style machine and save some costs by not running ground bar stock,” Peterson said about being able to remove the guide bushing. “Being able to eliminate that makes our parts that much more profitable.”

Peterson estimates that about 80 percent of the parts produced on the Polygim Zeit machine are made from unground bar stock. The ones that require ground stock are shaft-type parts at least 2½ " (63.5mm) long with surface finishes as fine as 16 µin. R_a, tolerances as tight as +0.0000 "/-0.0003 " (7.620µm) and concentricity to 0.0002 " (5.080µm).

The workpiece materials include 300 and 400 series stainless steel, beryllium copper, brass, bronze, plastics and titanium. “There is no material that we stay away from,” Peterson said.

Although the major new customer motivated Natoma to purchase the new machine, the company frequently uses it to reduce cycle times for some higher-volume runs from existing customers. The shop often machines the new customer’s orders for alignment shafts, generator and motor housings and other primarily aerospace components on other machines. “For some of the parts that we make 5,000 to 10,000 of a year, if you save a minute or a minute and a half per part, that pays huge dividends in the long run,” Peterson said.

With the equipment goal achieved, Natoma wants to utilize the full capacity of the Polygim Zeit machine, Peterson noted. Part of that process involved sending Travis Chisham, lathe foreman, and Jake Stalder, lead Eurotech setup technician, to a free training program Eurotech provides its customers. “They both came back with good ideas and a better understanding of the layout and format for the programming, which they are implementing on a program-by-program basis,” Peterson said. “We are still learning about the capabilities of this machine.”

For more information about the Polygim Zeit Model 42 SLY2-B CNC screw machine from Eurotech, view a video presentation at www.ctemag.com by scanning the QR matrix bar code on your smartphone or entering the following URL on your Web browser: cteplus.delivr.com/2x56c