Another aspect of push-button automation is the use of machinable features. Solid models in CAD/CAM systems are built from a set of interrelated features. In a CAM system, the capability of these features to describe a model is extended to include machining information that becomes integrated into the part model.

That way, any update to the model will automatically update the machining data at the same time.

Most CAM systems have standard milled features like pockets, holes, slots, bosses, grooves, and so on, plus specialized turning and wire EDM features. A true advantage is when the system allows a user to take the definition for a standard feature like a pocket and customize it to become a feature unique to an industry, like a runner or gate, with its own machining process that adapts to the shape of the feature. The CAM system can then automatically recognize a runner on a part model and know how to machine it according to a company’s specifications.

The automatic recognition of features is a key element of automation. A perfect example is the recognition of holes. CAM systems do an excellent job of recognizing holes in CAD models. In this case, every hole in a solid model can be recognized with a single click. Since CAM features also contain machining properties, the type, size, depth, chamfer or counter bore of each hole is recognized as well. The work plane for each hole is embedded in each feature as well, which is critical in determining the orientation of the part during drilling. Similar size holes can be grouped together to reduce tool changes, all holes can be linked and spot drilled first, and holes with a diameter too large for drilling can be recognized as milled holes. With full automation, feature recognition can kick off a process that generates every drilling operation in an optimized sequence without human intervention.
Features further enhance automation by allowing the system to:
Automatically recognize and drill (or mill) holes
Automatically recognize and machine standard and custom features