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A New Angle on Turning

Dec. 8, 2011
MAGs new sidehead option for VTCs offers 1,250 mm X-axis and 1,900 mm Z-axis, with 40-tool chain magazine

Tall, shaft-type parts mounted on the machine table and supported by a live center in the main ram, can be machined from a lateral angle to minimize bending forces on the part and machine components during maximum-thrust cuts, for faster, more efficient metal removal with highest accuracy.

A new “sidehead” option is being made available for MAG vertical turning centers (VTCs), involving a 250-mm-square (10-inch) ram to deliver 34,000 N (7,600 pounds) of thrust from the optimal angle for efficient turning of tall or flanged parts in vertical orientation. The sidehead option is available on machines with tables that range in size from 1,250 to 3,500 mm (49.2 - 137.7 inches), capable of handling parts up to 3,700 mm (145.6 inches) maximum diameter and 3,300 mm (129.9 inches) high. The sidehead provides a 1,250-mm (49.2-inch) X-axis span and 1,900-mm (74.8-inch) Z-axis, with a traverse rate of 20,000 mm/min (787 ipm). It is equipped for automatic tool change with a 40-tool chain magazine, and available with modular Capto C8 or KM tool interface.

With tall-shaft parts mounted on the machine table and supported by a live center in the main ram, the approach angle of the sidehead minimizes bending forces on the part and machine components during maximum-thrust cuts to allow faster and more efficient metal removal with highest accuracy. The sidehead also improves access for undercutting flanges or reaching features beneath them.

According to MAG the sidehead option is ideal for producing parts for the energy/power industry, heavy machinery, transportation and off-road equipment. It adds another level of one-stop processing capability to MAG VTCs, which can already be equipped for gear cutting and grinding.

One of the most versatile turning systems for large parts, MAG VTCs in table size 1,000 mm to 8,000 mm (39.4 - 315 inches) can already perform standard and hard turning, as well as live-spindle machining, contouring, and part probing operations on multiple sides and the full diameter of a part. Full contouring with the C-axis allows drilling or mill turning of features anywhere on the workpiece, with contouring/positioning by a 360,000-position table. Standard features include using modular tooling; green design with minimal hydraulics; minimal foundation requirements; and innovative chip management and removal that minimizes operator intervention.

The machines are designed with FEA-accuracy, for maximum strength-to-weight ratio, stiffness and rigidity, with heavily ribbed cast iron or sturdy steel weldments for major components (e.g., base, column and cross slide), depending on the machine size. The adjustable cross slide, with MAG's leveling technique and patented rail clamping system, makes it possible to minimize ram extension to ensure highest rigidity and accuracy during high-thrust cuts. Adjustable-rail models use dual linear scales to ensure parallelism between table and rail, with leveling accuracy of 10 microns (0.0004 inches).

The machines use a thermally symmetrical, hydrostatic main ram to resist torsion and vibration to produce superior surface finishes, delivering downward feed thrust up to 34,000 N (7,600 pounds). Preloaded roller guideways enhance system stiffness and reduce friction for excellent contouring accuracy.

Tables are extensively supported with a combination of tapered roller and flat thrust bearings to handle constant use at maximum load ratings. The table design resists tipping with unbalanced loads, and superior accuracy is ensured with factory-specified maximum 0.005 mm (0.0002 inch) table runout. Table drives are rated 46 kW (62 hp) to 142 kW (190 hp), and capable of producing maximum torque of 7,538 Nm (5,560 ft lb) to 255,000 Nm (188,000 ft lb).

A standard 26-position tool changer accommodates large, heavy boring bars and 20 modular tools. Various options for the VTC line include expanded tool capacity, part and tool probing systems, pallet changer and fourth axis. Fanuc 31i or Siemens 840D controls are standard.

About the Author

Robert Brooks | Content Director

Robert Brooks has been a business-to-business reporter, writer, editor, and columnist for more than 20 years, specializing in the primary metal and basic manufacturing industries.