Custom Turning with Only Two Operators

The company’s name is simply put: Custom Turning. That just about describes what a high intensity shop northwest of Minneapolis is about. The shop, in Big Lake, Minn., operates seven CNC turning machines, typically producing 100 different precision steel, stainless and titanium parts a month in lot sizes of a few hundred to tens of thousands for customers in a range of industries across the country.

 

But the fact that the shop does it all with only two operators and owners of the successful 10-year-old business is one of the most unique aspects of the company.

 

With only two people, the shop provides complete CNC mill-turn services plus CNC milling, CNC turning, inspection, prototyping, production and assembly.

 

In the field of turning in particular, there is a strong drive to manufacture parts complete in a single setup, including running production lights out, without operator attendance. Accomplishing these two objectives can make the difference between a busy shop and one with too much downtime.

 

And that is why partners Ken Schaff and Lloyd Campbell bought the first Emcoturn machine by EMCO Maier in 2001. They were pleased with the way the machine ran, and they began populating their floor with five more twin-turret Emcoturn machines with counterspindles and a larger capacity Hyperturn CNC turning center with Y-axis capability.

 

The partners once worked for a distributor that sold EMCO Maier machines. “What we liked about the machines is that we could do a part complete without a lot of extra labor for multiple setups, such as for second and third operations,” Mr. Schaff says. “That and the versatility of the Siemens 840D control, which makes programming complex parts fairly easy, are key to our operation here.”

 

The shop credits the machines with helping it survive and thrive in a tough business. “They’re accurate, reliable and durable and can do so much for you. We keep all the machines running, just the two of us. That’s how we stay alive.”

 

All turning machines are automated with bar loaders, which is part of the reason the shop can run lights out overnight. The machines are busy throughout the day, Mr. Schaff says.

 

Key machine tool requirements at the shop include high productivity for series production; complete machining from barstock to as much as 4 inches in diameter; chucking capacity to 16 inches; Y axis and driven tools; compatibility with existing toolholders; compact dimensions including bar loader (short bar loader); and Siemens control compatibility with the existing machine pool.

 

When Custom Turning needed an additional CNC lathe for a specific size range of parts, it contacted the company with its particular needs. Following the positive experience with the Emcoturn 332 CNC single-spindle turning center, the partners decided that the most important criterion was complete machining from barstock.

 

“We do a lot of parts for a variety of customers that require a variety of operations on a single part, from milling, drilling and tapping to cross-hole drilling,” Mr. Campbell says. “The machines may cost more to buy, but over time—and not a long time—because of the versatility of the machine and control plus the fact that we can run lights out, the payback is not hard to make.”

 

The company employs only a few people, two of them are the owners who run the seven machines three shifts a day, including any programming necessary. Maintenance is minimal as the machines are well-engineered and run well day in and day out. “We have machines running all night by themselves, so we don’t need a second or third shift of operators,” Mr. Campbell says. 

 

The two men keep their machines running throughout the day, maybe three to four setups a day, to fill customer orders.

 

The shop lot sizes are anywhere from 100 to 20,000 pieces, for customers including off-road OEM, gun manufacturing, display builders and more—all very highly engineered, complex parts, mainly out of steels, including stainless, and titanium machined to tolerances of 0.0001 to 0.0002 inch.

 

Some of the time saving machine features for Custom Turning include the tooling for the machines: All are interchangeable among the machines and every position in the turrets is live-tool capable. Changing tooling in and out of the machine takes only minutes. 

 

A further advantage of using the same or related machines with the same control technology is program compatibility. Since Custom Turning sometimes programs on the shop floor, this has certain benefits for the flexibility of the machine pool. 

 

Mr. Schaff says, “The Siemens’ program storage is larger than other controls, the editing features are 10 times faster, the response on the machine is faster than other controls and there is more versatility in programming on the control—we can easily create macros for a family of parts, for example.”

 

Tooling setup on the machines is straightforward. “With the Siemens control, we manually touch the tool tip off the part, and the control, with one button, sets the compensation for the part; it is very easy to set up tooling,” Mr. Schaff says.

 

A striking point about EMCO’s machine design is the compact construction, which conceals a surprising degree of technology: high-performance main and counterspindles, two turrets for as many as 12 driven tools each, which can be used with both main and counterspindles, water-cooled, integrated spindle motors, dynamic digital drives and thermo-symmetrical machine.

 

The shop runs four Emcoturn 332 MCs for screw machine-type work on parts between 1.25- and 4-inch diameter. They report the quick change-over time and the rigidity of the machines fit Custom Turning’s production of complex parts with milling and drilling operations. Plus, the 332 includes synchronized thread milling and polygonal turning capability.

 

The Hyperturn 690 at Custom Turning includes a Y axis with a 9-inch traverse path in the upper slide system and a Z2 axis in the lower slide system. The main and counterspindles are equipped with integrated, water-cooled spindle motors with drive power of 49-hp, 23-hp counterspindles, a maximum speed of 3,200 rpm. The main spindle exhibits torque of more than 500 foot-pounds, making it especially useful for processing large parts (to 20 inches in diameter) of tough material. 

 

The Y axis allows the shop to machine vertically off-center on a part for contour milling and off-center for cross-holes.  

 

Mr. Schaff also has a specific example to demonstrate the system’s outstanding technical performance: Complete machining of a workpiece with a high level of milling content (about 50 percent) on the 332 takes only 3 minutes. And the automated parts catcher—a standard feature on EMCO machines—collects the finished parts without interference in the work area.

“That’s an example of the way the machines are built for automated parts production, which helps us run untended for three shifts as needed,” Mr. Schaff says.

 

Custom Turning is also happy with the service, reliability and after-sales support provided by EMCO. It’s one of the main reasons the two men decided on these machines. According to them, the availability of spare parts and the company’s response times are top notch.

 

In addition, ergonomic considerations, such as locating the spindle and turret within easy reach of the machine operator, are essential for fatigue-free operation. The design is well thought out in this way.

 

According to the two men, they don’t just blindly buy from the company out of habit. “For our range of parts that we must do in one setup, we don’t see a comparable two-spindle machine on the market that offers such productivity from such a small space on our floor,” they report.

 

“Our customers aren’t just interested in increasing productivity. They also want backward compatibility with existing NC programs and often have large quantities of toolholders and clamping devices that need to be reused,” says Dana Abshier, EMCO sales V.P. “With our company, these are a few of the advantages they can count on.”