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As we all know, milling tools spin and turning tools are fixed. Even when multi-task machines were created to combine milling and turning in a single machining center, the attitudes about how these tools perform remained steadfast.

When you stop to think about it, a multi-task machine is supposed to do just as its name implies: multi-task. It’s more than just putting a mill and a lathe together. That’s exactly what the people at Mori Seiki, a leader in mill-turn centers, and Kennametal, a leader in cutting tool technology, thought when they decided to jointly develop a turning tool that spins. Why not take the best characteristics of both milling tools and turning tools and combine them into a tool that takes the best advantage of what multi-task machines have to offer?

The new Spinning Tool technology from Mori Seiki takes a unique

approach to live tooling on a multitasking machine tool for turning operations. This new type of cutting technology uses a turning insert similar to a round (full radius) insert except that, instead of being mounted on a turning holder, this specialized insert is mounted at the bottom of a cylindrical tool shank that is capable of spinning at high speeds.

A NEW TAKE ON TURNING TOOLSComputer-aided-manufacturing (CAM) industry innovator DP Technology, creator of ESPRIT®, put the new spinning turning tool to the test recently with a successful test cut that was the first to use the ESPRIT Spinning Turning Tool Add-In to generate tool path for the spinning tool. Designed to distribute heat and wear

By Ann Mazakas

Putting a spin on turning tools results in 2,000% increase in tool life and opens the door to new turning techniques.

The Evolution of Revolution in Lathe Tools

Kennametal Spinning Tool

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more effectively than a single-point lathe tool, the new spinning tool technology can increase productivity by up to 500 percent and tool life by up to 2,000 percent.

“This technology is promising because of all the advantages it provides,” said Olivier Thenoz, DP’s mill-turn product manager. “In the end, it means better productivity.”

This new cutting technology employs a specialized insert mounted at the bottom of a cylindrical tool shank held in a rotary spindle. The rotation of the spinning tool distributes the heat and wear around the entire diameter of the tool. The faster dissipation of heat also allows dry machining, so the costs of coolant and its disposal are eliminated. Mounted on a B-axis spindle, the tool can also be inclined as it cuts for even more effective cooling of the tool.

“The advantage of the spinning tool is that there is no one single point on the tool that is in contact with the work piece all the time,” Thenoz said, “and this is very good for heat dissipation and tool wear. Cutting conditions are no longer limited by the heat generated in the process, but by power available in the machine.”

ADVANCED TECHNOLOGYFOR ADVANCED TOOLINGThenoz teamed up with Nitin Chaphalkar, engineering team leader for Mori Seiki’s Machining Technology Laboratory (MTL) at the company’s Chicago Technical Center in February 2008 to perform the cut. Launched in 2006, MTL harnesses world-class expertise in machining to develop innovative technologies in a collaborative environment.

“It’s a great partnership with Mori Seiki,” Thenoz said of the development of the turning spinning-tool technology. “It’s important for us to be involved in this project and to have the

opportunity to perform test cuts like this one.”

The test included roughing and finishing operations on the outer diameter (OD) with a Mori Seiki NT4200. The full capabilities of the turning spinning tool were put to the test with OD passes on straights, tapers and arcs without the use of coolant on the steel work piece.

Because of the machine kinematics, the tool cuts on the YZ plane instead of the XZ plane. The tool can also be tilted (B-axis or angular holder) or moved above or below the center line.

For the initial OD rough cut, the spinning tool was inclined at a 20-degree angle, which, according to research conducted by MTL, is the angle that allows the most effective heat evacuation for this application. The turning spinning tool is also well adapted to cutting in a back-and-forth motion, and this capability was

also put to the test on taper and arc moves — with impressive results. The tool remained close to the material throughout the cut, and the repositioning moves necessary with the use of single-point tools cutting in a single direction were not required.

Immediately apparent at the start of the rough cut was the dramatic reduction in vibration and tool chatter, with the tool cutting smoothly and quietly through the material.

“Cutting forces generated while machining with single-point tools impart a bending movement on the tool and give rise to vibrations,” Chaphalkar said, explaining the potential benefits of an axially loaded tool. “In the case of axially loaded tools, such as a spinning tool, most of the cutting forces are directed axially into the spindle and hence significantly reduce vibrations. The point of this tool is to reduce vibration and chatter, and to increase tool life and productivity.”

Nitin Chaphalkar, engineering team leader for Mori Seiki’s Machining Technology Laboratory (MTL), and Olivier Thenoz, mill-turn product manager for DP Technology, complete a successful test cut with a

spinning tool on a Mori Seiki NT4200.

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The finish on the rough and the finish cuts was excellent. Prior to the test cut the post processor had been upgraded to support the new Spinning Tool technology. This allowed the NC program to run on the machine without the need to change a single line of code on the control.

STRENGTH OF THREEAccording to Chaphalkar, Kennametal Inc. pioneered the foundations of the spinning turning tool. Mori Seiki continued development and took its version of the tool into several CAM companies to solicit a solution for the new technology.

After being contacted by Mori Seiki in October of 2007, DP Technology became the only CAM company that demonstrated it was able to take on the challenge, and the ESPRIT Turning Spinning Tool Add-In was complete by the end of November.

Chaphalkar said that, while he was able to program basic functions by hand, the ESPRIT Turning Spinning Tool Add-In is the right solution for making the most of the tool. “With ESPRIT, the programming complexities are made easier and customers will be able to use the technology efficiently,” he said.

Thenoz said that developing for ease-of-use while making the most of new technology means better results for end-users with diverse needs. “We are looking for new programming challenges and are trying to stay ahead of all the new cutting technology,” Thenoz said. “We have shown that before, with the new B-axis turning, and this is a continuation of that philosophy. We want advanced functionalities and, at the same time, functionalities for everyone.”

ABOUT THE ESPRIT SPINNING TURNING TOOL ADD-INThe new ESPRIT Spinning Turning Tool Add-In makes it easy to use Mori Seiki’s new spinning tool technology.

The add-in provides a new interface to define the size and shape of the tool being used and adds new machining technology parameters to all standard

turning operations in ESPRIT that let the user define the rotation speed of the tool spindle and the angle of inclination for the cutting plane.

The ESPRIT Spinning Turning Tool Add-In makes it easy to use Mori Seiki’s new spinning tool technology.

The spinning tool was put to the test with straight rough cuts and back and forth finish cuts on angled and curved surfaces.

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DP Technology Corp. Phone: 1 800 627-84791150 Avenida Acaso Outside the US: + 1 805 388-6000Camarillo, CA 93012 USA Email: esprit@dptechnology.com

ESPRIT is a registered trademark of DP Technology Corp. ©2009 DP Technology Corp. All rights reserved.

For spinning tool turning operations, it is typical to set the tool spindle and turning spindles to the same revolutions per minute (RPM). The user has the option of creating the tool path in +Y or –Y in the YZ plane, and also has the ability to rotate the cutting plane about the Z axis to allow machining above or below the center line. The tilt of the tool is handled using a standard parameter available for any ESPRIT turning operation. ESPRIT supports full simulation of the cutting path with collision detection. The add-in also includes updated post processors for Mori Seiki machines. g

ON THE WEB:www.kennametal.comwww.moriseiki.comwww.moriseikiusa.com/MTL

A version of this article appeared in the December 2008 issue of Cutting Tool Engineering magazine.

about the authorANN MAZAKAS is Manager of Technical Communications at DP Technology, headquartered in Camarillo, CA. Her background includes many years in the manufacturing industry, particularly in the design and manufacture of products and molds. With a passionfor metalworking and CAD/CAM systems, she has been a writer since 1998.

Comparison of single-point tool and spinning tool

SINGLE-POINT TOOL All forces try to bend the tool, giving rise to vibration and

chatter. One point takes all the wear, the same point

absorbs all the heat. Cutting conditions are limited by heat,

which is dependent on the material.

SPINNING TOOL Cutting forces are directed axially into the tool spindle to reduce

vibration and chatter. Tool rotation distributes tool wear with a

constantly changing contact point. Tool rotation and tilt reduces

heat with air cooling for dry machining. Cutting conditions are

limited by the power available in the machine.