NUM Corp.
Nu Mgrind Software Camshaft Crankshaft 800

‘Off-the-Shelf’ Software for Non-Circular Grinding

Oct. 8, 2020
A new program allows grinding machine manufacturers and operators to introduce complex grinding functions, with a graphical HMI and a comprehensive library of predefined shapes.

NUM CORP. introduced a new software it said provides manufacturers of CNC cylindrical grinding machines with an effective way to incorporate non-circular grinding functions to their products without significant development time and cost.

Non-circular grinding is used in a variety of automated manufacturing applications, such as the production of camshafts, crankshafts, cams, and eccentric shafts. However, it is an extremely complex task, because the non-circular contour leads to constantly changing engagement and movement conditions between the grinding wheel and the workpiece.

NUM has added non-circular grinding functionality to its NUMgrind cylindrical grinding software, which forms an application-specific element of its Flexium+ CNC platform. It is fully compatible with other Flexium software, from release onwards.

NUMgrind simplifies the creation of G-code programs for CNC grinding machines using an intuitive graphical human machine interface (HMI), conversational-style ‘fill in the blanks’ type dialogues, or a combination of the two.

Unlike conventional CAD/CAM workstation tools for generating CNC machine tool control programs, NUMgrind is intended for use in the production environment. It enables shop floor personnel to handle everyday machining tasks very quickly and efficiently – and the work can be easily shared among several people and several machines. The NUMgrind HMI also canbe run on an office PC. Application-dependent projects, and the corresponding ISO part programs, can be created, tested with NUM’s Flexium 3D simulation software and transferred to the targeted machine.

The operator determines the sequence of the grinding process via the HMI and enters the necessary data for the grinding operations, grinding wheels, and dressing operations in the dialogue pages. Programming is simplified because the HMI is supported by a comprehensive library of predefined shapes, which includes eccentric circles, hexagons, pentagons, polygons, Reuleaux triangles, and rhombi. Then, the CNC program is created completely automatically and stored in an executable form.

The closed shape of the workpiece is defined in the XY plane. However, grinding is performed by interpolating or synchronizing the X axis with the C axis (workpiece spindle.) Axial movement in the Z axis also can be accommodated, by means of oscillation or ‘multi-plunge’. The Flexium+ CNC system’s NCK transforms the contour from the XY plane into an XC plane, and calculates the corresponding compensation and in-feed movements, taking the grinding wheel diameter into account. The speed profile is also transformed, so that the speed and acceleration are automatically adapted to suit the physical attributes of the machine.

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