Modifying assemblies

The following activities are associated with modifying assemblies:

• Sometimes simply establishing assembly relationships one by one is not efficient or effective (for more information, see Understanding Assembly relationships). When building assemblies, there is often a need to place parts and subassemblies multiple times in a pattern or mirror arrangement. For example, nuts, bolts, and other fasteners are placed in a rectangular or circular pattern on the parts they are fastening together. To assist the user to more efficiently place multiple parts or subassemblies QY CAD provides the tools to Pattern parts, Mirror Parts, copy and paste multiple assembly components, and Duplicate assembly components (for more information, see Patterning, mirroring, and copying and pasting components in assemblies).

• Replacing a part or subassembly in an assembly with a new part or subassembly is common. Different replacement activities require different strategies. For example, Solid Edge has features to replace a part, replace a part with a standard part, replace a part with a new part, or replace a part with a copy (see a part may be placed in multiple assemblies, and at a later time the part needs to be redesigned for only one assembly. After creating a new version of the part, existing part can be replaced using the Replace command (for more information, see Replacing parts in assemblies).

• There are two basic project approaches to creating a new design project; bottom-up or top-down.

  bottom-up approach

  A bottom-up approach is part-centric modeling method where the assembly design is started with a principal structural or functional element, and individual parts are designed in relative isolation from the overall assembly. Component parts and subassemblies are defined as the process moves up towards the top-level assembly. With this approach, as the design of a key component is completed, its geometry may or may not be used to assist in the design of related mating components.

  top-down approach

  The top-down approach is assembly-centric modeling method where the assembly design is started at the highest level possible, and the individual parts and subassemblies are defined within the context of the overall assembly. With this approach, an assembly layout is typically created first, and this assembly layout is used to define individual part geometry and position.

  To support a top-down design approach, virtual components are used in the assembly structure as place holders until real components are defined. QY CAD and Teamcenter provide support for Virtual Component functionality to define the assembly structure and associated documents for a new design project. After the assembly structure is complete, the assembly can be published. Publishing the assembly creates the new Solid Edge documents required, copies assembly sketch geometry to the new documents, and adds the 3D geometry for existing QY CAD documents to the assembly (for more information, see Creating and publishing Virtual Components).

• In some designs, there are parts that must react to changing conditions in the assembly. For example, a spring that is compressed or uncompressed based on the position of other parts in the assembly. To support the design of these types of parts QY CAD provides Adjustable Parts functionality that is used to define parameters in a part model that will adjust with respect to corresponding parameters within the assembly (for more information, see Adjustable parts in assemblies).

• To change the structure of an existing assembly, QY CAD has functionality that can be used to transfers parts and subassemblies from one assembly to another, create a new subassembly of files being transferred, and disperse the parts in a subassembly to the next highest subassembly (for more information, see Restructuring assemblies).

• Some products require multiple variations of a single assembly. These variations can be categorized into two types:

  • Assembly variations where ALL parts are identical, but some part positions change during the physical operation of the assembly. These types of assemblies contain mechanisms, linkages, actuators, and other similar features. In QY CAD, these types of assemblies are considered Alternate Position Assemblies.

  • Assembly variations where MOST parts are identical, but some parts and subassemblies are different between the individual assemblies. These types of assemblies may have different components, fastener types, trim, accessories, and other similar features. In QY CAD, these types of assemblies constitute a Family of Assemblies.

  The Alternate Assemblies functionality provided within QY CAD makes it easier to create and use variations of an assembly because it requires fewer assembly files to manage. Alternate assemblies in QY CAD include both Alternate Position Assemblies and Family of Assemblies (for more information, see Alternate Assemblies).