Flexible Turning

Tool carriers are arranged around the spindles of an MS22-6L so that two tools can be used at each of the six spindles.

The Index B400 has a Siemens Sinumerik 840D sl controller; The Traub TNA 400 (not pictured) instead comes standard with Mitsubishi TX8i-s V8 controls—one of the few differences between the machines.

As seen through the window of an iXcenter cell, a Fanuc LR Mate 200 iD 7L robot loads a blank into the C200 turning center.

An Index employee demonstrates undocking the iXcenter cell from the work area of the C200.

Previous Next

Precision metalcutting equipment developer Index Group (us.index-traub.com) has launched a number of new turning solutions. If there is a common theme, it is “flexibility,” as each of the machines enables the user to complete a wider variety of tasks, faster, on a single machine rather than having to employ multiples.

Traditional and Swiss Turning Together
 

The MS22-6L may be the best example. The basic MS22-6 (without the “L”) is a multispindle, front-opening lathe for machining bar. It has live tooling and C and Y axes to allow such options as off-center drilling and threading, contouring and hobbing, or polygonal turning. The central module consists of six spindles integrated into the spindle drum. This is already a machine that allows a wide range of operations. And to it, the company has integrated Swiss-style turning capabilities, which makes it an “L.”

As with regular Swiss-type machines, bar is fed through the guide bushing, which supports it as it is being cut by the turning tool. The core of the MS22-6L’s Swiss turning unit is a centered guide block on which six long turning sleeves are moving. The ball-bearing guide bushing unit is equipped with a guide clamp that can be programmed with different pressures, depending upon the operation. When milling (via live tooling), for example, the clamp grips the bar for added stability.

The combination of traditional and Swiss turning on a single machine makes it versatile and flexible. The Swiss-style capabilities enable long turned parts up to a workpiece length of 7.87 inches (200 mm) and a bar diameter of 0.2 to 0.9 inches (5 to 22 mm). The tool carriers are arranged so two tools can be used at each of the six spindles. That’s up to 12 tools in use.

“For long, narrow turned parts, the ratio of length to diameter made precision machining on a standard CNC lathe impossible. To produce such parts in high quantities, the only solution was to use a number of single-spindle Swiss-style sliding headstock machines,” noted Index CTO and COO Dirk Prust.

In contrast, he said, one MS22-6L can achieve the part output of up to six single-spindle Swiss lathes. And getting that output on one machine means other savings—from needing not six but one part-handling system, one coolant preparation, fewer operators and a fraction of the electricity and floor space—accrue as well, he noted.

Modular Approach
 

The company says it extends the range of what any given machine can do not only with the design of the basic model but also by increasing the number of possible optional configurations. This reflects a key goal at Index of increasing the use of modular designs.

“We believe the future is platforms and in modules,” Prust said. “The belief is that 100 percent of our products should be made with no more than 50 percent of the modules. We’re right on track for that.”

The extreme examples for machines being built from shared platforms and modules are the Index B400 and Traub TNA400 universal turning machines. They share more than the same belt-driven 32-hp (24-kW) main spindle. In fact, other than different CNC controls—Siemens for the Index and Mitsubishi for the Traub—and a difference in toolholder arrangement, they’re the same machine. The Index is blue; the Traub is red—that’s about it. But as Traub had a long history before being acquired by Index, each still has its loyal customers.

Options the machines share—here’s that modularity—include a counter spindle designed to accommodate smaller bar and chucked parts; and an electrically positioned, hydraulically operated numerically controlled steady rest, useful for external machining of long shafts.

Flexible Automation
 

Index has redesigned the C200, a production turning machine, now with better ergonomics, part handling and coolant capacity—and its use of an iXcenter robot cell.

A bit about the C200 first: it’s designed for simultaneous machining with two or, optionally, three turrets with 10 (or 14) stations, allowing a broad range of parts to be machined. With the option of using two Y axes on the main spindle or one each on the main and counter spindles, the machine can handle complex operations efficiently. There is a choice of CNC controls—a Fanuc CNC 31i-B with 15-inch touchscreen or the Siemens S840D sl with an 18.5-inch touchscreen.

There are also a range of automation options, including a gantry load/unload setup. But they’ve developed something that goes beyond simple part handling.: iXcenter is an enclosed, compact robot cell with a vertical pallet storage system. The entire cell docks to the turning machine. During production, the iXcenter clicks in place in front of the machine’s work area. A 6-axis Fanuc robot (with a 13.2-lb payload capacity) accesses the C200’s work envelope through the primary door of the machine, which slides opens automatically behind the robot cell.

The cell’s vertical storage system can hold up to 22 stacked 23.6 × 15.7-inch pallets. Pallets of blanks are loaded at the top by the robot, while pallets with finished parts are removed at the bottom This can be done at any time with no interruption of production. Downstream processes such as cleaning, measuring, deburring, etc., can also be integrated in the robot cell.

When the cell is docked and the robot is at work at the exact same location, the machine/cell combination look and act like a single unit—seamless in appearance as well as production. But during the setup process—or, notably, on any occasion where non-automated turning operations are necessary—the cell simply swings aside, hugging the wall of the machine while enabling unobstructed access to the work area. And when needed again, it can lock right back into place.