Upon successful completion of this lesson, you will be able to:
I Find and fix errors in the assembly.
I Gather information about the assembly.
I Create features that represent post-assembly machining operations.
I Replace and modify components in an assembly.
I Mirror components in an assembly.
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Assembly Editing
Like part editing, assembly editing has specific tools to aid in repairing errors and problems. Some tools are common to both parts and
assemblies and were covered in basic course SolidWorks Essentials.
They are not repeated here.
Key Topics Some of the key topics in this lesson are shown in the following list.
Each of these topics corresponds to a section in the lesson.
I Assembly Features
An assembly feature is a feature which exists only in the assembly. This includes cuts, holes, fillets, chamfers, etc. Assembly features often represent post-assembly machining operations.
I Replacing and Modifying Components
When an assembly is open, there are a number of techniques you can use to replace or modify components. These include File, Save As, Replace Components and Reload.
I Troubleshooting an Assembly
Mates are treated as features in the FeatureManager design tree and are edited using Edit Feature. Mates can have several problems. Chief among them are missing references (faces, edges, planes) and over defined status.
Over defined components in an assembly are the 3D analogy of an over defined sketch. Using the same notation, the plus sign (+), they indicate that the component or mate has conflicting mates applied to it.
I Information From an Assembly
If you are unsure where all the components used in your assembly reside, Find References will locate them and provide an option for copying them.
I Controlling Dimensions in an Assembly
To capture design intent, dimensions can be controlled using in-context features, global variables, or equations.
I Mirroring Components
Many assemblies have some degree of left-right symmetry.
Components and sub-assemblies can be mirrored to reverse their orientation. This can also generate “opposite hand” parts.
Editing Activities Assembly editing covers a wide range of operations from repairing errors to extracting information and making design changes. This section will discuss how to perform each of these operations.
Design Changes Making design changes to an assembly can range from changing the value of a distance mate to replacing one component with another. You can modify the dimensions of individual components, model in-context features, or you can create assembly features to represent
post-assembly machining operations.
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Finding and Repairing Problems
Finding and repairing problems in an assembly is a key skill in SolidWorks. Problems can occur in mates, assembly features or in the component parts and sub-assemblies referenced by the assembly.
Common problems, such as an over defined component, can trigger many more error messages and cause the assembly to stop solving the mates. Several common errors and their solutions are presented here.
Information From an Assembly
Nondestructive testing of an assembly can yield many important insights as to how the assembly, and the components that comprise it, were created. It is also important to find potential problems such as interferences.
1 Open an assembly file.
Open Edit_Assembly from the Lesson06\Case Study\Editing folder.
The Hole Wizard You can add any Hole Wizard hole as an assembly feature that extends through more than one component.
Where to Find It I CommandManager: Assembly > Assembly Features > Hole Wizard
I Menu: Insert, Assembly Feature, Hole, Wizard
Tip We are not creating a Hole Series as we did in Lesson 2: Assembly Features and Smart Fasteners. Using the Hole Wizard at the assembly level creates holes that exist only in the assembly.
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2 Hole Wizard.
Select the face indicated below and click Hole Wizard .
Set the Hole Specification as follows:
I Tap
I Standard: Ansi Metric
I Type: Bottoming Tapped Hole
I Size: M6x1.0
I End Condition: Blind 15mm
Introducing: Feature Scope
The Feature Scope controls which components are acted upon by the assembly feature. You can set the feature scope before or after you create the assembly feature.
If you do not specify the feature scope at creation of the assembly feature, SolidWorks selects appropriate components in the assembly based on their position relative to the placement point(s).
3 Feature Scope.
Expand the Feature Scope area of the dialog. The choices include All components and Selected components, with the option for Auto-select. The default settings, Selected components and Auto-select, are acceptable for now.
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4 Locate hole centers.
Click on the Positions tab of the dialog. Create sketch points as shown. Click OK.
Note In this example, bracket and table are selected by the feature scope.
5 Resulting holes.
Two holes are added. A single feature appears as the last feature in the FeatureManager design tree as a Tapped Hole feature.
6 Components.
Open bracket and table. The holes do not appear.
Close both parts.
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Assembly Feature Changes
Changes to the assembly feature can fall into two categories: changes to the feature itself (its sketch or end conditions, for example) and changes to the Feature Scope. It can be modified to be an in-context feature that exists in both parts like a hole series feature.
Where to Find It I Shortcut Menu: Right-click the assembly feature and click Edit Feature
7 Edit the Feature Scope.
Edit the hole feature. In the Feature Scope area of the dialog, click Propagate feature to parts. Click OK.
The parts now share the hole feature.
8 Save the file.
Converting Parts and Assemblies
There are several methods that convert parts into assemblies or assemblies into parts. These methods offer techniques to accomplish many unique design tasks.
Parts into Assemblies
Using a part to create an assembly can offer a simpler method of modeling that avoids mates and inserting parts. It is useful for industrial design.
Split Part Use Split Part to break a single solid body part into a multi body part and optionally an assembly.
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Assemblies into Parts
There are performance advantages associated with using a part in place of an assembly. For example, if it is known that a particular sub-assembly is not going to change, it could be replaced with a part in a larger assembly. Weldments appear in a BOM as a single part but may be created with multiple parts.
Joined Components Multiple part components in an assembly can be joined into a single part using Join. This results in a part that references an assembly and multiple parts.
Save As Part Save As can combine an assembly into a part. Options include selection of only outside faces/components or all. Saving as a part creates a part that references an assembly and multiple parts.
Parts into Parts Another approach to creating weldments or FEM models is to use multi bodies to turn multiple parts into a single one.
Multibodies Use Insert Part, Move/Copy Bodies and Combine to turn multiple solid bodies into a single body part. Using insert part and combine results in a part that references multiple parts.
Replacing Parts with Assemblies
Component parts can be replaced with assemblies using Replace Component (see Replacing a Single Instance on page 181). The same procedure can be used in reverse to replace an assembly with a part, or to replace an assembly with another assembly.
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Replacing and Modifying Components
Components can be replaced in an open assembly using either of the following techniques, Save As, Reload or Replace Components.
Working in a Multi-user Environment
For other people to make changes to components that are in an assembly you are working on, they must have write access to those components. That means you must have read-only access.
When an assembly is opened, the latest saved version of its components is displayed. Once the assembly is open and you make changes to its components, you are asked whether you want to rebuild the assembly whenever you switch back to the assembly window. This lets you keep your display of the assembly up-to-date.
However, if other people make changes to the parts in your assembly, those changes are not displayed automatically. This is an important consideration when working in a multi-user environment.
Technique Description
Save As If you are editing a part in the context of an assembly, or if you have a part and the assembly open at the same time, using Save As to rename the part will cause the new version to replace the original in the assembly. If there are multiple instances of that component, they will all be replaced. The system will issue a warning
message alerting you that this will happen. If you do not want to replace the component, click the Save as copy option on the Save As dialog.
See Replacing Components Using Save As on page 189 for an example.
Reload and Replace Components
The Reload and Replace Components options refresh or replace all instances or selected instances of a selected component with a last-saved or read-only version or a different
component entirely. Reload will preserve all mate information. When you replace a component in an assembly, the system will try to preserve the mates. If the names of the entities referenced by the mate remain the same, the mates will be preserved when the component is reloaded or replaced.
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If you have read-only files in your assembly, the command Check Read-only Files checks if files have been made available for write access or have changed on disk since the last reload. A message appears if the files did not change, and the Reload dialog box appears if any files changed.
For more on multi-user environments and collaborative file sharing, see the SolidWorks File Management training manual.
Introducing:
Replace Components
ReplaceComponents removes a component or an instance of a component in the assembly and replace it with another component.
Where to Find It I Menu: File, Replace
I Shortcut Menu: Right-click the component and click Replace Components
Using Replace Components
In the ReplaceComponents dialog, the selected component appears under Replace these Component(s); others may be added as well.
Use the All instances check box if required. Browse for a file to substitute a different component for the original in the With this one field. Replace Components will affect selected or all instances of that component in the active assembly.
If you want to replace a component with a modified version of that same component, follow these rules for best results:
I Make a copy of the component, either in Windows Explorer, or by using File, Save As and, if necessary, the Save as copy option.
I Make the desired modifications to the part.
For best results in preserving the mates, the replacement component should be similar in topology and shape to the one being replaced. If the names of the entities referenced by the mate remain the same, the mates will be preserved when the component is replaced.
Caution: Any changes to an unsaved file are lost when it is reloaded.
Replacing a Single Instance
To replace just one instance of a component, Replace Components must be used. The Save As method will replace all instances.
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Hidden Options SolidWorks limits the length of long pull-downs by showing only a limited set of options.
The Replace Components option is one of these hidden options. Right-clicking a component will not display this option unless the pull-down is expanded by clicking the double chevron symbol.
To force options to appear by default, click Customize Menu and click the
appropriate checkbox in the left column.
9 Replace component.
Right-click Pin from the FeatureManager design tree and click Replace Components. The selected instance is listed in the Replace these component(s) field. Clear the All instances box and click Re-attach mates.
10 Browse.
Click Browse, select the part T_Pin, and select Open. Click OK. The Mated Entities dialog appears.
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Troubleshooting an Assembly
Although the component instance is replaced, there are mate errors.
The problem is that the internal ID’s of the geometry are different.
Mate Errors Mate errors for all components appear within the mate folder of the assembly and the mate folder of each component.
Errors can occur due to several different conditions. When the
FeatureManager design tree is expanded, you can see the differences in the display of the mates. In this case, the mates have Missing
References. Several types of mate errors are described below.
Automatic Repairs When changes are being made to a mate, other mates can be affected. A common issue is that the alignment must be flipped to prevent further errors. In these cases, SolidWorks may reverse the alignment
automatically and open a message dialog:
The alignment of the following mates was reversed to prevent mate errors:
Condition Description Solution
Missing Reference
The mate cannot find one or both of its references. This could mean that the referenced component has been suppressed, deleted or changed enough that the mate cannot be solved. This is similar to a dangling dimension in a sketch.
These problems are usually repaired by selecting a replace-ment reference.
Over Defined
The mates have both the error marker and the plus sign (+) prefix, meaning they are both over defining and unsatisfied. Example error message could read:
Coincident74: Planar faces are not parallel.
Angle is 90deg.
The over defined mates relate directly to an over defined component which is also marked with the plus sign.
Delete or edit the mate that caused the problem. The best practice is to take care of over defined mates when they occur, not later.
Warning A Warning is applied to mates that are satisfied but are over defining the assembly. The error message reads:
Distance1: Warning: This mate is over defining the assembly. Consider deleting some of the over defining mates.
Delete or edit the over defining mate.
Suppressed Suppressed mates are not really errors, but they can cause problems if they are forgotten. When a mate is
suppressed, it appears grayed out in the FeatureManager design tree and it is not solved.
Unsuppress the
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Mated Entities The Mated Entities tool replaces any reference in a mate. It includes a preview to show the replacement faces and a pop-up dialog to isolate components or delete mates. It also has a filter that shows only
dangling mates that need repair. It is used with Replace Components and Re-attach Mates.
Tip The references used in a mate can be highlighted in the graphics window with a single-click on the mate. For mates that contain
dimensions (distance and angle), double-clicking the mate displays the dimension so it can be edited.
Where to Find It I Shortcut Menu: Right-click a mate or the mate group and click Replace Mate Entities
I Replace PropertyManager: Select Re-attach Mates
Note As you would expect, Edit Feature edits the references of a mate. The same interface used with Insert, Mate is used for editing. On the mates with errors, one of the references is listed as **Invalid**. Once the mate is repaired, you can also change the mate type. For example, a mate between planar faces could be changed from Coincident to Parallel, Perpendicular, Distance or Angle.
11 Mated entities.
The Mated Entities dialog appears to assist in re-attaching the failed mates. Expand the mates and select the replacement faces for each one.
As they are replaced, a green check mark appears. Click OK.
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The completed replacement has no mate errors and functions similar to the original part.
More information regarding mate and component errors is discussed in the following section.
Over Defined Mates and Components
Finding the cause of an over defined assembly is not always easy because there can be two or more conflicting mates. All the over defined mates will appear with error markers and the (+) prefix, which will help in narrowing down the choices. When mates conflict, one approach is to suppress the over defining mates one at a time, until the assembly is no longer over defined. This can help you identify the cause of the conflict. Once you have done this, you can either delete the offending mates, or redefine them using different references.
Geometry is Important
Underlying errors in the accuracy of the geometric models can also be a cause of over defined mates. For example, consider what would happen if you mated the sides of a simple box to the three default reference planes in an assembly. Three coincident mates should fully define the component. However, if the sides of the box do not meet at 90° angles, even if they were off by only a fraction of a degree, the assembly will be over defined. Unless you check the accuracy of the underlying geometry, you will have a difficult time solving the problem.
Finding an Over Defining Mate
Finding the mate that is the cause of an over defined assembly can be difficult in a large assembly with many mates. One way is to look at the components listed in the mate. Another choice is to use View Mates and Dependencies and look at the FeatureManager design tree from the perspective of the mates rather than the features.
Best Practice Fix errors as they occur.
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12 Add mate.
To demonstrate what happens when a mate over defines the assembly, add a Distance mate of 10mm between the faces of the components, as shown.
13 Forcing the mate to solve.
When you add the Distance mate, a message appears:
The selected mate could not be successfully added. Would you like to force this mate to solve? (Other mates will be broken, and will be shown with red errors).
Add the mate by clicking OK in the Mate dialog and Yes in the warning message.
14 Error flags.
In Mates, again we see all the mates that are conflicted as a result of the new mate.
Mates which are not satisfied are highlighted with a red (X) error flag.
Mates which are satisfied, but which over define the assembly, are highlighted with a yellow exclamation point warning flag.
Components in the assembly are now also over defined. These are prefixed with the plus (+) symbol.
For more information, see Mate Errors on page 183.
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MateXpert MateXpert is a tool that enables you to identify mating problems in an assembly. You can examine the details of mates that are not satisfied,
MateXpert MateXpert is a tool that enables you to identify mating problems in an assembly. You can examine the details of mates that are not satisfied,