Advanced 5-Axis Operations: Doosan TCP Mode for 5-Axis Machining - G700/G701 The MX-Series has both a Nutating (Articulating) head and a Rotary Axis (C1 Left Main Spindle ,C2 Right Main Spindle). The C-Axis(C1 & C2) is mechanically independent of the B-Axis head. If we do not use TCP (Tool Center Point) mode then we are required to use the traditional method of calculating X, Y, Z, C and B. In a CAM system, the part will remain static and the system will create 5-axis toolpath vectors around the desired geometry. These vectors represent the centerline axis of the cutting tool and are used to calculate the required position and angles.
The tip of the tool will have XYZ positions based relative to the origin of the part in the CAM system. On a machine like the MX-Series, the C axis angle would be calculated first. This is necessary to align a tool vector to the ZX plane as the B-Axis only rotates in this plane. Once that angle of rotation is known, the CAM system then calculates the X,Y positions required based on the C axis rotation. Since the Z-axis is the centerline of the C axis rotation, the Z axis position isn't effected by the C axis rotation. We now have the new X, Y, Z and C known within the CAM system. The CAM system next calculates the B-Axis angle based on the toolpath vectors.
Since all tools have differing lengths, the position of the B-Axis head needs to be adjusted based on those tools lengths and B-Axis angle. The only coordinates effected by the length of the tool and the B-Axis rotation are X & Z. Our next step is to calculate new X & Z coordinates based on the distance from the tip of the tool to the center of rotation of the B-axis head. This process would need to be repeated for every toolpath point. All of these calculations are typically handled within the Post-Processor of the CAM system. The Post-Processor is the last step in the process as it formats any work done in a CAM system to a useable NC Code file that will operate a CNC Machine Tool. - 53 -