Hyundai WIA Machine Corp.
The L800A Big Bore CNC turning center has a 10in throughhole capacity for machining large cylindrical parts

Excitement Surrounds ‘Big Bore’ Turning Center

Aug. 9, 2012
45-degree slant bed Spindle bore of 12.58 in./320 mm diameter Double locking system forspindle bearing 700-rpm spindle for taking deep cuts

Hyundai WIA introduced its L800A CNC turning center — the Big Bore machine — with a 12.5-in. through-hole capacity that makes it well suited for machining large cylindrical parts, like those in demand from the oil-and-gas market, including oilfield pipe, and other applications that demand handling long, cylindrical pipe and tubing in high-volume production.

A dual chuck design (one on each end of the spindle) offers supports workpiece — especially on long shafts or pipe.   Standard capacities include a 41.3-in. swing over the bed; a 32.3-in. swing over the carriage; a max. turning diameter of 36.2 in.; a max. turning length of 65 in. and a 12.58-in. spindle bar capacity.

The developer said the L800A Big Bore is a new example of its expertise at designing and building high-production machine tools. South Korea-based Hyundai WIA Machine Corp. manufactures machining equipment, robots, industrial machinery, aircraft parts, and iron and steel products.

Bed structure — The 45-degree slant bedwith hardened and ground box ways was designed using finite element analysis (FEA) to ensure powerful cutting and agility, cast in Meehanite cst iron to minimize deformation during heavy-duty cuts.Weighing nearly 4,000 lb., the rigid bed absorbs vibration for stable machining.To eliminate thermal growth during machining, all axes are driven by high precision double-nut ballscrews. The double pretension design provides excellentpositioning and repeatability with virtually no thermal growth. All ballscrews are connected directly to the servo drive motors without gears or belts, eliminatingbacklash.   

  • Axes travel: 19.7 X 66 in., in Z and B.

Geared head spindle — The Big Bore’s spindle drives a bore hole of 12.58 in. (320 mm) diameter, to optimize cutting efficiency for oil pipeline products and other types of pipe. The 60-hp spindle motor is torque rated at 7,045 Nm. 

The spindle achieveshigh material removal rates too, withaccuracy and rigidity,guaranteeing  stability for high rpm precision machining.

  • Chuck size: 32in.
  • Spindle nose: A1-20.

P4 class roller bearings and angular bearings secure stability during heavy-duty cutting.  Ground bearing assembly parts in the spindle and headstock maintain consistent high accuracy.

To avoid the release of pre-pressure of the spindle bearing due to high-speed acceleration/deceleration, heavy-duty cutting,and movement of the chuck cylinder and tension of the belt pulley, a double locking system separates the spindle bearing from the pulley. The three-step gearbox offers powerful low end torque for heavy cuts, as well as high-speed rotation for improved surface finish.

The L800A Big Bore is configured with a 700-rpm spindle for taking deep cuts.The main spindle delivers minimalnoise and vibration even during very heavycutting, guaranteeing high-stability machining and minimizing thermal transmission to the main spindle.

Built-in tail stock — The L800A Big Bore has an easy-to-use, programmable built-in tail stock to maintain superior accuracy and tailstock control.

  • Taper: MT6. 
  • Quill diameter: 160 mm.
  • Quill travel: 132 mm.
  • Tail stock travel: 1,580 mm.

Turret — The Hyundai WIA L800A Big Bore has a 12-tool turret.

  • Tool size: OD, 32 x 32 mm, and ID, 80 mm.
  • Indexing time: 0.4 sec per step.
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. His work has covered a wide range of topics, including process technology, resource development, material selection, product design, workforce development, and industrial market strategies, among others. Currently, he specializes in subjects related to metal component and product design, development, and manufacturing — including castings, forgings, machined parts, and fabrications.

Brooks is a graduate of Kenyon College (B.A. English, Political Science) and Emory University (M.A. English.)

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