Assembly Features

While in an assembly, you can create features that affect component parts.

You determine which parts you want the feature to affect by setting the scope. You can specify whether the feature exists only in the assembly file or propagates to the part file. You can create a pattern of assembly features in the same manner as you create a pattern of features in a part.

Use an assembly feature if, in manufacturing, the feature is added after the components are assembled and the feature affects more than one component. For example, use assembly features such as Cut > Extrude when you need to represent post-assembly material-removal operations.

When you want to add a feature to a single component in an assembly, it is better to create the feature in the part rather than the assembly. To do so, you can do one of the following:
  • Edit the part in context.
  • Create the feature in the assembly and then propagate it to the part by selecting Propagate feature to parts in the PropertyManager.

While it is not a requirement, it is good practice to fully define the positions of the components of the assembly, or fix their locations, before you add assembly features. This helps prevent unexpected results if you move the components later.

Assembly Features and Top-Down Design

Assembly features are not associated with top-down design. The geometry of the parts (as they exist in the part files and drawings) is not defined by the geometry in the assembly (using a layout sketch or other parts). No external references are created.

For example, holes in assembly components such as bearings, gears, and components with bolt holes are manufactured in the parts before assembly. For these cases, create the holes in the part documents. If you then want to define the location of those holes based on assembly geometry, for example using a layout sketch or the geometry of a different part, that is top-down design.