Assembly modeling consists in using mechanical components to group geometric entities in hierarchies, representing the structure of a designed product. Assembly modeling is commonly used in Mechanical Computer-Aided Design (MCAD) applications, because it simplifies the design of complex products containing thousands and millions of geometric entities.
A mechanical component is a named group of entities. A mechanical component can be any .dwg file or a standard hardware part. Users can define their own components. A component can be inserted once or several times into one or more other components. If the component is modified, all instances of the component will reflect these changes automatically. Components cannot be self-referencing.
A component insert is a named entity, of which the default name is composed of the name of the component and the serial number of the insert.
An assembly is a mechanical component that contains other components.
An assembly with inserted components (which in turn can be assemblies with other inserted components) forms a tree that is called a mechanical structure of the drawing. This tree is displayed in the Mechanical Browser.
Users can create mechanical components from scratch or add them to existing .dwg
External and local components
Mechanical components can be either local or external. A local component is stored in the .dwg file with the assembly. An external component is stored in a separate .dwg file. All inserts of external components are updated automatically when the corresponding .dwg file is modified. If you use external components in your assembly, always remember to transfer all related files when you want to share your model.
You can always convert a local component to an external one and vice versa.
To edit a local component it needs to be converted to an external component using BmExternalize command. Alternatively you can use the BmOpenCopy command to open a copy of a component, edit and save it, and then use the BmReplace command to replace the original with the copy.
You can choose the default insertion type for your component: Local or External. To change the type select the root node in the Mechanical Browser and select Local or Externalfrom Insert as properties:
Depending on the value of BMAUTOUPDATE, inserts of external components are updated automatically on opening the assembly document or manually with the BmUpdatecommand. You can change this value in the Settings dialog:
Converting components
Wykonaj jedno z poniższych:
-
Click the Switch Component to External (
) or Switch Component to Local tool on the Assembly ribbon tab. The tools are also available on the Assembly toolbar and in the Assembly menu.
-
Right click on the component insert in the Mechanical Browser and select Switch to External or Switch to Local in the context menu.
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Hover your mouse cursor over a component insert in a drawing window and select Switch to External (
) or Switch to Local (
) in the Assembly Modeling command group in the Quad.
-
Type BmExternalize or BmLocalize in the command bar.
When you convert an external component to local, the .dwg file with the component definition is not deleted, but its future changes will not affect your assembly.
You can always distinguish between inserts of local components () and inserts of external components (
) by their icons in the Mechanical Browser:
KOMPONENTY PARAMETRYCZNE
Parametric Components
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You can control whether a particular component parameter will be available for editing in a drawing containing the inserts of this components (at the assembly level). To do that, select the corresponding parameter in the Mechanical Browser and change the value of the Exposed field in the properties grid of the parameter:
The options are:
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Off:Hides the parameters at the assembly O
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On: Makes the parameter visible at the assembly level.
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Auto: Hides all parameters which values are controlled by expressions, and exposes all other parameters.
You can associate units with a parameter. If you assign a value, directly or via an expression, to a component parameter at the assembly level, it is automatically converted from drawing units of the assembly drawing to the units of the parameter. Values assigned to unitless parameters are not converted.
By default all parameters are unitless except parameters of dimensional constraints and parameters, which are used as expressions for dimensional constraints. BricsCAD automatically assigns drawing units to such parameters.
An insert of a parametric component gets a Parameters node in the Mechanical Browser. Each dimensional constraint in the component generates a parameter.
When a parametric component is inserted in a model, you can edit the parameters either in the Mechanical Browser or in the Properties Bar.
To edit a parameter in the Mechanical Browser
- Expand the Parameters node of the component.
- Select the parameter.
- In the Parameter section, type a new value in the Expression field .
To edit a parameter in the Properties Bar
- Select the component in the drawing.
- Expand the Parameters settings group.
- Type a new value for one of the available parameters.
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Zastępowanie komponentów
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Wykonaj jedno z poniższych:
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Click Replace Component tool () on the Assembly ribbon tab. The tool is available on the Assembly toolbar and in the Assembly menu.
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Right click on the component insert in the Mechanical Browser and select Replace&ldots; or Replace all inserts&ldots; in the context menu
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Hover over a component insert in a drawing window and select the Replace tool (
) in the Quad menu.
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Type BmReplace in the command bar
A File open dialog displays.
2. Select a .dwg file for the replacement component and press the Open button.
You are prompted: Replace file for all similar inserts [Yes/No] <Yes>:
3. Wykonaj jedno z poniższych:
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Yes: Replace all inserts of the same name.
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No: Replace the selected insert only.
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Parameter values which are shared between the replacement component and the replaced component are copied automatically, which allows intelligent replacement of parametric components. |
Replacing Components
Component inserts can be replaced with another component. Only top-level inserts can be replaced.
-
Wykonaj jedno z poniższych:
-
Click the Initialize Mechanical Structure tool (
) in the ribbon tab. The tool is also available in the Assembly toolbar and in the Assembly menu.
-
Type BmMech in the command bar
A File open dialog displays.
2. Type a name for the mechanical component or press Enter to accept the current name or the default Component_1 name.
You are prompted: Convert blocks and external references to mechanical components? [No/Yes] <Yes>:
3. Press Enter to convert blocks and external references to mechanical components.
Components, blocks and external References
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Wykonaj jedno z poniższych:
-
Click The Remove Structure tool (
) on Assembly ribbon tab. The tool is also available in the Assembly toolbar and in the Assembly menu.
-
Type BmUnmech in the command bar.
Drawings with blocks and external references can be converted to mechanical assemblies: block references are converted to inserts of local components, and external references are converted to inserts of external components.
2. Press Enter to:
-
Convert external components to External References (Xrefs).
-
Convert local components to blocks.
A feature is a physical constituent of a part, which has engineering significance. Examples of features are holes, ribs, slots, pockets, forms. Being applied to a 3D solid, a feature removes and/or adds some volumes to it. You can create your own features using BricsCAD component extension technology.
An extended component has BC_SUBTRACT and/or BC_UNITE layers. When you insert such a component on a face of any 3D solid using the BmInsert command, this target solid is modified as follows:
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all 3D solids located on BC_SUBTRACT layer of the component are subtracted from the target 3D solid;
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all 3D solids located on BC_UNITE layer of the component are united with the target 3D solid.
All faces created after these Boolean operations form a component based feature, which is updated when you change the component insert &endash; by moving it along a target 3d solid or by modifying its parameters (if the extended component was parametric). When the insert is deleted, the feature is deleted as well.
Some examples of parametric component-based features are included into your BricsCAD installation. You can use them as samples for creating your own features.
Assigning a physical material
A mechanical component may have an assigned physical material.
To assign a material:
-
Select the root component in the Mechanical Browser.
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Select Material property and press the Browse button (
).
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In the Physical Materials dialog select a material in the In Project or the the In Library list.
If a material from the In Library list is chosen, it will be copied to the In Project database automatically. -
Click the OK button to save changes and to assign the selected material to the component.
To remove the material from the component:
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Select the root component in the Mechanical Browser.
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Select Material property and press the Clear button (X)
If a mechanical component does not have an assigned material, it will inherit the material from its parental component. If the parental component also does not have an assigned material, the material of the closest component with an assigned material in the hierarchy will be used. It means that you can assign a material to several components having a common parent at once by assigning the material to their common parent component.
Inserting a component with a physical material
If you insert a mechanical component into a document, all materials used in this component will be automatically copied to the document material library. Only materials assigned to the components will be copied. However, if the current document already has a material with the same name, this material will be used instead. It means that the properties of the material defined in the document library will be used rather than properties of the material from the inserted component.
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Materials which are copied to the document material library will not be erased in Undo operations. |