CAD Automation in NX using Knowledge-Fusion and UDFs compared to in I-deas using Open Ideas and Parametric Template Parts

In an I-deas environment one of the preferred methods of automating geometry generation is to use parametric template parts. Using Open-Ideas functions, a copy of template part can be brought from the TDM library onto the workbench and values of different parameters can be modified programmatically to create a new part off the template part. This approach works well as long as part topology is fixed. If the topology varies among the different parts, which need to be created off the template part, it may require a unique template part for each variation, particularly if the variation is at the wireframe or sketch level. If the variation is at the feature level, sometime one can get away with using one or fewer template parts by suppressing/un-suppressing features programmatically to be able to create unique parts. Regardless, whether the variation is at wireframe level or at feature level, the solution is very cumbersome and awkward. In the case of wireframe variation, multiple template parts need to be maintained, which is a very time consuming and tedious tasks. And in the case of feature variation, the size of the history tree becomes very large as it contains superset of all possible features. With I-deas going away in coming years and NX taking over, it seems like we have an elegant solution to the problem described above, in the form of Knowledge-Fusion.

Knowledge-Fusion (KF) is a knowledge-driven programming environment within NX. KF has solution to both the problems described above. A given part can be broken into bunch of unique features. Udfs (user defined features) can then be created for each unique feature and stored in a library. Using KF, the logic can be defined (in a .dfa file) to use only required features (udfs) for a given situation, to create a unique part. Hence the part history does not contain extra features as in case of ideas (suppressed features) described above. Figure 1 below shows an example of an Engine valve defined using three udfs. Similarly, KF allows one to program logic within a single .dfa file to create unique wireframes (sketches). Figure 2 below shows an example of Engine Connecting Rod designs requiring 4 unique wireframes and template parts. In summary NX-KF environment is extremely versatile and flexible and provides solution to most of the problems (if not all) encountered by the CAD/KBE programmers within I-deas environment.