Computer-aided manufacturing ( CAM , dt. Computer-aided manufacturing ) use designated one of the CNC independent machine software to create the NC code and is one aspect of production engineering and work preparation (in companies). Using the NC code, for example, cutting machines or 3D printers are controlled. In contrast to the creation of the NC code in the workshop ( WOP ), with the CAM system the NC program is already created in the work preparation. CAM is an essential part of computer integrated manufacturing (CIM computer integrated manufacturing ).
Instead of conventional drawings, the NC program for the part to be created should be created directly on the basis of the CAD data produced on the computer . The necessary instructions for the CNC machine and the instructions for the operator should no longer have to be printed out, but should be transferred to production in electronic form.
Because no geometry data has to be copied from a drawing, errors cannot be made. The CNC machine remains productive while working on the CAM system. With CAM programming you can sit in the office instead of standing in the workshop. Regardless of the CNC machine for which a program is created, the software used for this can always be operated in the same way. Own functions and experiences can be stored in the CAM system so that recurring tasks can be solved faster and more reliably. If there is an error in the NC program, you do NOT have to go back to work preparation in the CAM system to correct it. A shop floor editor can be used for this, which ensures that production can continue in the 2nd and 3rd shifts. In addition to the CAD, the CAM system can also exchange information with other applications (e.g. with tool management and the PPS system ). A CAM system can be used to create NC programs for freeform surfaces (e.g. for a bonnet). The created NC program can be checked quickly and in advance for collisions and other errors with the CAM system. The list of tools needed can be drawn up in advance. When using tool management, the setpoints can be transferred directly to the presetting device for measuring the tools. Subsequent changes in the design can be recognized quickly and adopted from the CAD. A CAM system can also be used to create work plans that, together with photos or film sequences, tools, cycle times of the component and clamping situations, are included in the production process, which simplifies and accelerates the set-up and execution of the order.
The CAM system requires an adapted post processor for each CNC machine . If no CAD data is available, you have to record the geometry of the desired finished part yourself. The machining performance of the CNC machine is significantly increased by NC programs that have been created with the help of a CAM system, if they calculate the optimal tool path, avoid air cuts and optimally adapt the tool geometry to the intended machining (e.g. wave-shaped roughing ). New simulations based on the machine environment provide a large safety factor. The work in the workshop is less demanding and therefore less interesting. With older CNC machines without a network connection, the NC programs created on the computer must be transferred to the machine control using special DNC software.
A CAM system costs money and needs to be trained to use it, but it saves a lot of time in operation, as the machine operator does not type sentence by sentence in the machine noise, which leads to careless mistakes. The biggest disadvantage is that CAM systems only simulate the neutral code before the postprocessor, but not the original NC code after the postprocessor run. So to be really sure, you should run the simulation in a special simulation system.
The profit from a CAM system also includes the graphic display, on the computer screen or for several viewers in projection . The number of milling or turning cuts can be made clear and the different movements with a certain direction and speed or in rapid traverse can be clearly seen in different colors.
The geometry data for the raw part, finished part and clamping device are read in from the CAD in the CAM system. Occasionally it is necessary to change the geometry or to create new geometry (models). The material and the CNC machine are selected from tables so that the CAM system knows the boundary conditions and can suggest suitable traversing movements and cutting values.
The tools required for machining are taken from the tool management or recorded in the CAM.
The operations required to machine the part are specified in sequence. The geometry to be processed and the desired tool are selected in the graphic. The parameters proposed by the CAM system for processing are adjusted manually if necessary. Operations that have already been defined can be simulated for control purposes.
When all operations have been determined, the machine-specific NC program is generated and saved with the post processor . The instructions for the operator and the tool list are printed out or saved. The operations defined in the CAM are saved together with all parameters as "source code" in the CAM internal format.
In addition to the respective order-related processing of data, archiving and standardization is one of the tasks of the CAM.
Commercial products (selection)
- Autodesk : HSM (Works, Express, Inventor), PowerMill, FeatureCAM, PartMaker, ArtCAM, Delcam Robot, Fusion 360
- EXAPT : EXAPTplus and EXAPTsolid
- NX (Siemens)