BHMR CNC

The BHMR CNC cylindrical grinder is a fully CNC‑controlled universal center grinding machine designed for high‑precision grinding of external and internal cylindrical and taper surfaces. The machine combines excellent versatility, high productivity and long‑term process stability, making it suitable for single‑piece, small‑batch and cost‑effective serial production.

Workpieces can be clamped between centres or mounted in a chuck (optional equipment) in the drive headstock. The BHMR CNC supports longitudinal grinding, sequential plunge grinding, as well as plunge grinding with a stationary or oscillating table. When clamping between centres, both cylindrical and conical parts can be ground longitudinally. Long tapers can be ground using interpolation of the X and Z axes.

The grinding wheel head is double‑sided swivelling and allows perpendicular plunge grinding when tilted, which is particularly advantageous for steep taper grinding and for simultaneous grinding of cylindrical and adjacent face surfaces.

Automatic B axis and CNC grinding capabilities of BHMR

A key feature of the BHMR CNC grinder is the automatically controlled vertical B axis, enabling precise positioning of the grinding wheel head. The grinding head can be equipped with up to three tools, significantly expanding the technological capabilities of the machine.

This design allows multiple grinding operations in a single clamping, reducing auxiliary times and improving process repeatability. Interpolation of the perpendicular axes – Z axis (longitudinal table feed) and X axis (wheel head infeed) – enables a wide range of grinding methods and form dressing operations, for both external and internal grinding wheels.

Face surfaces of the workpiece can be ground using the side of the grinding wheel, or by peripheral grinding when the workpiece is clamped in a chuck and the drive headstock is rotated by 90°.

Grinding accuracy, performance and applications

The BHMR CNC cylindrical grinder is designed for high‑performance grinding of workpieces weighing up to 850 kg, or up to 1000 kg when grinding in open rests. The machine achieves a standard working accuracy of IT 4, while enhanced versions allow accuracies down to 0.004 mm, and optionally up to 0.002 mm.

An automatic grinding cycle, combined with adjustment options and the possibility of integrating measuring equipment, makes the BHMR suitable not only for flexible job‑shop use but also for economical serial production. The machine meets increasing demands for higher productivity while maintaining its universal application range and ease of operation.

CNC control system and drives

The BHMR CNC grinder is equipped with the SINUMERIK 840D sl control system and SINAMICS S120 servo drives on the X, Z and B axes. This configuration provides high dynamic performance, precise positioning and stable machine behaviour, even during demanding grinding operations.

Machine bed and guideways of the BHMR CNC grinder

The machine bed and table are made from high‑quality grey cast iron, ensuring excellent rigidity and effective vibration damping. After casting, all major components undergo a controlled ageing process, followed by rough machining.

All guideway surfaces of the bed and table are then precision‑ground on specialised guideway grinding machines and subsequently hand‑scraped. This ensures superior sliding properties, high guiding accuracy and long‑term geometric stability of the machine.