Delcam Italia will be showing the latest developments for the machining and inspection of composites at the Open House to be held by Italian CNC machining centre manufacturer Belotti from 14th to 16th December. These will include the new releases of its PowerMILL machining software for high-speed and five-axis machining and of the PowerINSPECT inspection software, plus a range of adaptive machining solutions to allow more accurate manufacture of composite components.
PowerMILL is used by many composites manufacturers for the production of master models, moulds, jigs and fixtures, as well as for the trimming and drilling of components. The latest release includes new strategies like flowline machining, to give smoother machining and a better surface finish. The program also includes a range of enhancements the to existing functionality to enable both faster programming and more efficient machining.
PowerINSPECT is firmly established as the world’s leading hardware-independent inspection software. It combines the ability to work with all types of inspection device with a comprehensive range of inspection routines for making simple measurements, for inspecting geometric features and for checking complex surfaces. The resulting reports present detailed information in easy-to-read formats that can be understood by all engineers, not just inspection specialists.
The latest release provides support for 64-bit computers to enable increased memory use on that hardware. This will be of benefit for more memory-intensive applications where larger CAD files need to be manipulated, especially for very complex parts and multi-component assemblies.
Delcam will also demonstrate new ways in which machining and inspection can be integrated to give adaptive machining. One example of this integration is electronic fixturing. With this technique, toolpaths are adjusted to match the actual position of the surface of the workpiece, rather than trying to align the part into exactly the nominal position specified in the CAM system. It can overcome the problems caused when machining large, flexible composite panels.
Another problem in the machining of composites is that the materials tend to relax as the composite fibers are cut. This is not as serious as might be thought since any pockets tend to be undersize and so can be corrected with an extra machining operation.
To overcome this problem, the initial machining operation should be followed by an inspection on the machine tool with a probe fitted where the cutting tool would normally be. This shows how much more material needs to be removed and enables the required extra toolpaths to be generated in the company’s CAM system. For more complex components, with twenty or more pockets, a further cycle of inspection and machining may well be needed to produce all the dimensions to the required tolerance. However, for subsequent parts in a series, the complete machining sequence can be repeated and the results checked with a final inspection.
A similar problem can arise when drilling holes as the relaxation of the surface can alter their final positions. One solution is to use a two-stage drilling operation. The first sequence is done using an under-size drill, typically half of the size required for the final hole. The surface of the part is then scanned and the results used to create a second drilling routine with the correct size of tool. Any distortion of the part will be picked up by the scan and the centers of the second series of holes can be adjusted accordingly.