Machining a mold in a virtual environment is quite similar to setting up and running an actual prove-out on the machine tool. First, the user specifies the stock from which the part will be cut, either by entering dimensions into the software or using a CAD model. Then, after selecting cutting tools,

the NC program is used to simulate the motion of the tool removing material from the stock. The programmer can watch the material removal process and see details of how each cut changes the shape of the part. This eliminates having to try to imagine how cuts from the current operation will affect subsequent operations.

During the cutting simulation, the software automatically detects problems such as fast feed errors, gouges and collisions that could potentially scrap the part, break the cutter or crash the machine. If an error is discovered, the programmer easily identifies the offending NC program record by mouse clicking on the error. The problem can then be fixed in the CAM software so that an error-free NC program is sent to the machine.

Analysis of the as-cut mold delves deeper into the verification process. Is the resulting mold dimensionally accurate? Does it match the final desired mold shape? NC verification software enables the user to zoom in on suspect areas for in-depth inspection. The part can be rotated and cross-sectioned at any angle to check areas that would otherwise be impossible to see, such as the intersection of drilled holes. Detailed measurement tools enable the user to verify dimensions such as wall and floor thickness, hole diameters, corner radii, scallop heights, depth, gaps, distances, angles, volumes, etc.

Some simulation/optimization software also provides the ability to automatically compare the as-cut part with the original design, and includes the ability to embed the CAD design model inside the stock, automatically comparing the design to the in-process workpiece in order to reveal any differences such as gouges or excess material not removed by the machining processes.

After running the simulation and making sure the NC program contains no errors, and that the resulting part is dimensionally accurate and matches the design, the NC program can be run on the machine without needing to waste time machining a test part.