3D Assemblies

VariCAD enables you to define connections between part files, sub-assembly files and assembly files. Parts can be created and edited in their own files and then inserted into assemblies. If a part is edited, the change is transferred to all assemblies that contain the part. In addition, you can change a part within the assembly file and update the original part file, as well as other assemblies that contain the part. It is generally faster and more efficient to edit parts in their own files, since there is much less data in these files. But editing within the assembly can be handy if you need to edit only a small detail, especially a detail that affects other parts.

If the current file contains any parts inserted from another files, the file becomes an assembly file, and "Assembly" is displayed on the right side of the Status Bar. If the file contains a part used in an assembly, or an object identified as a part, "Part" appears on the Status Bar. If the current file is a sub-assembly, “Subassembly” is displayed. If the current file is assembly and contains also defined sub-assembly group, “Assembly+Sub.” is displayed.

Using links between parts and assemblies provides many advantages. However, you do not have to use links when working with multiple solids. Unlike other CAD systems, VariCAD provides freedom and flexibility when working with assemblies.

Creating Part Files, Assembly Files and Assembly Links

There are several ways to create assembly-part links:

• In the current file, select an object and use the Create Link from Part function. Define the filename for the part, and the object is saved to this file. The current file becomes the assembly file
• In the current file, select an object and use the Create Link to Assembly (Assemblies) function to "mark" the part to be used later in an assembly. Only one object in a file can be identified as a part.
• Make the current file as assembly by using File / Insert Objects from File and insert a file containing the defined part.

Saving and Loading the Assembly Files

While editing an assembly file, changes can be saved to part files as well as to the current assembly file. When opening an assembly file, the parts are loaded as they were last saved then the parts are updated from the part files. Therefore, if parts are changed after the assembly was saved, the changed parts will be used.

If part files cannot be located, a list of broken assembly links is displayed and you can use the following methods to resolve them:

• Leave the part as it was saved in assembly, and you can resolve links later. If you know the part file has not changed since the assembly was closed, this is the best option.
• Break the link permanently.
• Search for another file or directory. If there are parts in another directory, you can select one of them as a replacement. The new directory is identified, and you can change all links to use this path.

If you choose not to resolve any links, the parts will remain as they were saved last in the assembly.

Sub-assemblies

Instead of a single part inserted into assemblies, you can also define a group of solids as a sub-assembly. The sub-assembly objects are single separate objects in a sub-assembly file. When inserted into an assembly, they behave as one compact object.

The group of sub-assembly objects may contain also parts inserted from part files, or other sub-assemblies inserted from sub-assembly files. On the other side, in assembly file the sub-assembly may be also a member of sub-assembly group ready for insertion into higher level. This allows you to create a hierarchical structure of entire product.

The structure of assembly and sub-assemblies is displayed in BOM, see BOM Objects.

In many ways, sub-assemblies behave similarly as parts inserted into assemblies. But there are also significant differences:

• Unlike part inserted from a part-file, the sub-assemblies cannot be modified in assemblies. To modify a sub-assembly, right-click it and from menu, select “Open as part file”. Then perform changes at the separate sub-assembly file.
• Sub-assemblies are created from multiple objects. You can add objects into a sub-assembly group, delete objects from the group or change their mutual positions.
• When a part is inserted into assemblies, transformation uses the part’s insertion axes. However, a sub-assembly contains multiple objects. The insertion axes are defined separately for entire sub-assembly, in an extra step.
• A part may have defined its own attributes, like name, material etc… These attributes are defined for a single solid, both in part file and assembly file. Contrary to this, attributes of a sub-assembly in assembly file are data defined in the corresponding sub-assembly file as file attributes – see Assembly, Sub-assembly or Part Attributes, Fill Title Blocks.

Relative Paths in Assembly Links

By default, VariCAD uses absolute paths for all assembly to part or assembly to sub-assembly links. You can change the usage of absolute paths – in following command:

Complete System Settings - CFG

Here, in section 3D, “Assembly link settings”, you can define how to solve changed paths, if an assembly is open:

• Changed paths are not solved – it means, that only absolute paths are used. In case the part or sub-assembly is not found, you must solve the problem individually.
• Change of path is solved for the beginning of the path. This option can be used, if parts or sub-assemblies are stored at a server and if computers have differently mapped access to the server. For instance, the same path may begin with “J:\” at one computer, with “Z:\” at other computer and with “/mnt/” at third computer, using Linux.
• Complete changed path. This option is intended for situations when files are copied among different computers often, and different paths are used at each computer. In this case, parts or sub-assemblies must be saved in path under assembly or at the same level. If parts are used in multiple assemblies or sub-assemblies, they should be in one directory, “under” the path where assemblies are.

Paths are separated by “\” in Windows, and by “/” in UNIX. In assembly links used in VariCAD, separators are automatically handled according to current operating system. By other words – if assemblies and their parts are copied from Linux to Windows, path separators are changed automatically. If some computers in network use Windows and some use Linux, VariCAD assembly links are solved automatically, too.

Simultaneously Open Assembly and Part Files

VariCAD allows you to work with multiple open files. While working in the assembly file, you can open part files from the assembly. Transferring changes between parts is managed by the following function:

Complete System Settings - CFG

Open Part File from Assembly - EDE

Select the part, and its file is open. If the part in an assembly is changed, changes are transferred into a newly open file automatically only if the transfer is allowed (see above).

Do not close changed part files or sub-assembly files, if you want to transfer changes to the assembly. Files must be switched, not closed.

Definition of Assembly-Part links

Create Part, Save It into New Part File - DIA

Defines a selected object as a part and exports it to its own file. The current file becomes the assembly, and the part-assembly link is established.

Define Part to be Inserted into Assembly - DEE

Command defines the selected object as a part. The current document becomes a part file.

Change Definition of Part to be Inserted into Assembly - ROI

If a file has a defined part, use this function to define a different part. Corresponding parts in all assemblies are changed according to this selection.

Definition of Sub-assembly-Part links

Create Sub-Assembly, Save It into New Sub-Assembly File -SBA

Defines selected objects as a sub-assembly and exports them into their own file. The current file becomes an assembly, and the sub-assembly - assembly link is established.

Define or Change Sub-Assembly to be Inserted into Assembly - SBE

Command defines the selected objects as a sub-assembly. The current document becomes a sub-assembly file.

Breaking Links between Part or Sub-assembly and Assembly

Break Link from Part or Sub-assembly - CSI

In current assembly, breaks the assembly link for one group defined by the selected solid.

Break Definition of Part to be Inserted into Assembly - CDE

In current part file, breaks the part definition. The file is no longer a part file.

Break Definition of Sub-Assembly to be Inserted into Assembly - CSB

In current sub-assembly file, break the sub-assembly definition. The file is no longer a sub-assembly file.

Break All Links from Parts or Sub-assemblies - CAI

Break all links in the current assembly. The current file loses its assembly status.