The change in the market forces machining companies to update product design, complexity, quality, durability and delivery times. This is made possible by the development of computer technology. During the development of a 3D model in CAD (Computer Aided Design), data can be adjusted quickly. On the basis of Model Based Definition (see techsheet model based definition) all relevant data concerning the product can be placed inside the 3D CAD model. By using feature recognition the CAM system can execute machining strategies automatically (Stănăşel, Blaga, & Buidoş, 2019).
Once the 3D CAD model is loaded in the CAM program, the feature recognition tool can automatically recognize types of operations such as holes, slots and pockets (Sheen & You, 2006). Because these processing rules have already been defined, a quick identification is possible, after which the functions are automatically specified (Stănăşel et al., 2019). The users of the CAM program can change the editing knowledge at any time.
When sufficient information has been added to the program, a fully automatic production process can be achieved. However, the technology is currently limited to 2,5D prismatic features. At the moment, relatively simple features, such as holes, can be automatically generated with feature recognition. This reduces the overall programming time and leaves more time for the programmers to work on challenging features.
What is the difference between macro programming and feature recognition?
In order to make this difference clear, it must be clear what feature recognition means. Assigning operations with feature recognition can be applied in two ways, namely data-based and rule-based and. The method(s) that can be used is CAM package dependent.
With data-based feature recognition, features are recognized on the basis of previously entered macros. The difference between macro programming and feature recognition is that with macro programming the operator has to manually connect the macro to the features, while this process is automatic when using feature recognition. The second option is rule-based. Rule based are written rules, with which the CAM program can independently determine which tools are required for an operation (Artificial Intelligence). Rule-based is automatic and has nothing in common with macro programming.
Why is feature recognition so important?
Feature based machining drastically reduces programming times. The use of standardised processes reduces the risk of human errors, because one knows from experience that the operation will work flawless. These effects ensures that machining companies can remain competitive on the market (Stănăşel et al., 2019).
Bibliography
[1] Sheen, B.-T., & You, C.-F. (2006). Machining feature recognition and tool-path generation for 3-axis CNC milling. Computer-Aided Design, 38(6), 553–562. https://doi.org/10.1016/j.cad.2005.05.003
[2] Stănăşel, I., Blaga, F. S., & Buidoş, T. (2019). Manufacturing based on feature recognition using NX. IOP Conference Series: Materials Science and Engineering, 568, 012015. https://doi.org/10.1088/1757-899x/568/1/012015
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