NOTE: When the P is not specified, a P0 is assumed for using Euler Angles. The method of defining the Work Plane is designated by the P address. The G68.2 Tilted Work Plane function allows user to define the Work Plane by Euler Angles, Roll-Pitch-Yaw, 3 Points, 2 Vectors, Projections Angles. G68.4 is the Incremental Mode (G91) command. (NOTE: There is a variation of this command defined by G68.3). G68.2 is the Absolute Mode (G90) command and is the most common. The FANUC command for Tilted Work Planes is G68.2. Let's first take a look at how FANUC handles Tilted Work Planes for a Head/Head type 5-Axis Machine. We'll address those reasons in a future article. The reason for using it with such machines is decidedly different. While Tilted Work Plane functionality has pronounced benefits with Head/Head type 5-Axis Machines, It may also be used with Table/Table and Head/Table Hybrid 5-Axis machines. Among these are FANUC and SIEMENS, two of the most popular CNC Control Systems today. This would be reflected in the NC code by large NC program files that were largely point-to-point movements.Īs CNC Control Systems have become much more powerful, this problem is largely a thing of past. Almost every CNC control used on 5-Axis machines today has some version of a function for handling Tilted Work Planes. Circular Interpolation, Cutter Radius Compensation and Drilling Cycles are all standard programming tools that couldn't be used. Because of this limitation, many CNC Programming functions, that are taken for granted for 3-axis, could not be used. In the past, this presented additional challenges as the CNC Control Systems were not powerful enough to help manage the various Work Plane orientations. A Head/Head machine achieves the required orientations by rotating and aligning the Spindle/Tool Axis to be perpendicular to the Work Plane that will contain the features to be machined. Large work-pieces that require machining from various orientations are typically done with Head/Head or Articulating Head 5-Axis machines. With the larger work-pieces that are typical of Aerospace, Energy and Automotive industries, this type of machine is impractical. With smaller work-pieces, 5-Axis machines with Table/Table or Dual-Rotary Table configurations accomplish this by simply rotating to align the Work Plane to be parallel to the XY-Plane (G17) and perpendicular to the Spindle/Z-Axis. Meaning, the 5-Axis machine will position to a specific orientation with its two rotary axes then perform standard 2-1/2 Axis & 3-Axis operations. The overwhelming majority of 5-Axis machining operations are actually what can be more correctly classified as 3 + 2 operations. While true 5-Axis simultaneous machining has definitely become more popular, the truth is that 5-Axis simultaneous is a very small part of machining when viewed in the context of all machining operations.