Integrated CAD/CAM CNC process chain
Computer-aided design (CAD) is a computer-supported design and development process. The product is created on-screen down to the last accurate detail. While CAD used to be similar to technical drawing, modern systems such as NX-CAD have developed into complex expert systems. For example, a finite element analysis or flow and heat-transfer analysis can be conducted in the very early phases of development. However, CAD also has a role to play in CNC production planning: Here, the focus is not on making constructive changes to the CAD data provided, but rather on analyzing and – where applicable – adding to the CAD data for CNC production. In CNC production planning, the technician becomes the designer, when it comes to modeling clamping aids, special tools, or more complex blank geometries using CAD. With this in mind, the integration of the CAD and CAM module, as in NX, is a key productivity factor.
Computer-aided manufacturing (CAM) involves using software that is independent of the CNC machine tool to create the NC code. Unlike workshop-oriented programming (WOP), NC programs are created during production planning. A CAM system’s main task is to transform CAD data into tool paths. As such, the integration of the CAM system and the CNC control is a major advantage. For example, when machining free-form surfaces it is extremely important for the CAM system to accurately parameterize the CNC’s speed. NX and SINUMERIK are perfectly matched in this respect: NX provides the Cycle832 high-speed-setting cycle with the required data, which allows the SINUMERIK in the machine to perform at its best.
Increasingly complex machine concepts mean that measures for avoiding collisions are required, ideally during CNC production planning. CAM systems offer simulation modules that ensure process efficiency and reliability in CNC production. The depiction of tool paths can be expanded by integrating tool geometries and blank dimensions for removal simulation. In the case of simulation with virtual machine tools, the tool paths are also displayed on a 3D model of the machine. This enables identification of both collisions between the tool and the workpiece and collisions between the tool and the machine or clamping aids. The virtual machine in NX-CAM significantly increases process reliability. While traditional CAM systems simply supply the simulation with neutral – CNC-independent – tool paths, NX-CAM uses the CNC parts program translated by the postprocessor as an input value. This means that NX includes the impact of the CNC in the simulation result. The outcome is a more precise process image than offered by traditional CAM systems – and therefore greater process reliability.