Republic Lagun’s VTBC-R series vertical turning and boring center provides cutting flexibility for very large or asymmetrical workpieces. The machine accommodates loads as heavy as 46,297 lbs (21,000 kg) and offers a maximum turning diameter of 98.43" (2,500 mm). The one-piece, cast iron Meehanite column features a squared structure and ribbing for stiffness and stability. The VTBC-R63 and VTBC-R78 models both feature a 15-degree slant bed design for increased surface area, said to enhance rigidity. The turning and boring center can be equipped with an optional C axis and live tooling to enable vertical lathe cutting operations such as milling, drilling and grinding.
The machine’s ram is made of steel alloy with a high-torque octagonal structure for supporting cutting forces of internal and external diameters while achieving tight tolerance. According to Republic Lagun, the ram design improves vibration damping, enhances thermal expansion control and increases rigidity.
The turning and boring center is driven by a class 3 ballscrew coupling with a direct-drive FANUC servomotor. The pre-tensioned ballscrew and preloaded bearings on all axes help to minimize thermal distortion. The X- and Z-axis slideways are hand-scraped and Moglice-coated for improved alignment and friction-free movement. The worktable is equipped with hydrostatic and dual-type roller bearings, increasing the load capacity while ensuring high precision and quality surface finish. The X axis can counterbalance the Z-axis frontal tilting with its inclined squared rail design.
The cross-rail height can be adjusted based on geometric workpiece dimensions. The 31.50" (800-mm) stroke is evenly divided by five positions, each locked with four independent hydraulic clamping cylinders and large taper lock pins. According to the company, the clamps strengthen the rigidity of the cross-rail while improving positioning and repeatability.