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FAQ Mates

Changing, Deleting, or Suppressing Mates

Answers: Managing Mates

  1. Why can I not have redundant dimensions or distance mates?
    The software treats dimensions as parametric, modifiable entities. If you could add dimensions to entities already defined by relations or mates, you could violate the relations or mates by modifying the dimension. For example:
    FAQRedntDims1.gif Fully-defined sketch.
    FAQRedntDims2.gif Redundant perpendicular relation added. Sketch is still fully defined.
    FAQRedntDims3.gif Redundant dimension added. Sketch is over defined.

    Changing the dimension later to something other than 90° would conflict with the relations. To prevent this potential conflict, the software makes the sketch over defined, requiring you to delete the dimension, make the dimension driven, or delete relations.

    Additionally, resolving conflicts is more difficult when redundant relations exist. You would have to delete the perpendicular relation and the adjacent horizontal or vertical relation. The SketchXpert functionality displays all possible solutions.

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  2. What are the best practices I should follow to set up mates?
    To Maximize... Use this technique...
    Robustness and Performance Mate components to a common component for optimum performance.
    Robustness Use face-to-face mates, if your design intent permits, because they tend to be more robust and predictable.
    Performance Use subassemblies to limit the number of top-level mates. The application solves all top level mates whenever it rebuilds an assembly.

    Click AssemblyXpert Tool_AssemblyXpert_Tools.gif (Tools toolbar) to display assembly statistics.

    Efficiency when adding mates
    • Use mate references if your models use similar components that you need to replace regularly. Click Mate Reference Tool_Mate_Reference_Geometry.gif (Reference Geometry toolbar) and set the mates.
    • Use Smart Mates.

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  3. How do I know what mates are on a part?
    In the assembly's FeatureManager design tree, do one of the following:
    • Right-click a component and select View Mates.
    • Right-click the assembly feature and select Tree Display > View Mates and dependencies. Expand components to see the mates.

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  4. What do I do if I get a mate I don't want?
    Use these techniques:
    • Click Undo PM_undo.gif if you have not yet closed the Mate PropertyManager.
    • Suppress the mate. Right-click the mate in the FeatureManager design tree, select Properties, then select Suppressed.
    • Use MateXpert to diagnose and resolve mating problems. Click Tools > MateXpert.
    • Check the Mate alignment under Standard Mates in the Mate PropertyManager.

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  5. What do I do if my mate combinations cause errors or move parts in unexpected ways?
    Use these techniques:
    • You may have conflicting mates. Use MateXpert to check for conflicting mates, then delete or edit one of the conflicting mates. Click Tools > MateXpert.
    • You may have an improper Mate alignment. Edit the mate and in the Mate PropertyManager, under Standard Mates, click Aligned PM_mate_aligned.gif or Anti-Aligned PM_mate_antialigned.gif for Mate alignment.
    • Use MateXpert to diagnose and resolve mating problems. Click Tools > MateXpert.
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  6. When I add a mate, my parts do not move as expected. Why?

    When you mate to an analytical surface, a valid solution is to mate to the virtual extension of the analytical surface. The components might not move as you expect.

    To try to achieve the desired mate, move the components as close to the correct position as possible.

    In this assembly, you want to place the lever's edge on the half cylinder.
    FAQMateMove_1Original.gif FAQMateMove_2Desired.gif
    Original Position Desired Position
    FAQMateMove_3Sel.gif FAQMateMove_4MovesWhy.gif
    Select entities to mate. Position after the mate is applied. Why does the lever move here?
    The lever mates to the virtual extension of the analytical surface, shown in red.
    FAQMateMove_6MoveCloser.gif FAQMateMove_7Final.gif
    Move the lever closer to the correct position, then apply the mate. The lever mates to the correct position.

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  7. A component will not move when I try to drag it. Why?
    Do these checks:
    • Check if the part has mates that restrict movement. A tooltip appears if the part is fully defined.
    • Check if the part is fixed. A tooltip appears at the location you pick if the part is fixed.
    • Check if the part is fixed. A tooltip appears at the location you pick if the part is fixed.
    • Try dragging the part from a different spot.
    • Check the mates because the setup may be incorrect.
    • For a mechanism, try dragging a different part.
    • Sometimes you cannot move a part by dragging it. Try adding a mate to move the part.

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  8. Does the order I apply constraints matter?


    You can apply constraints in any order.

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  9. Can I use mates to temporarily position parts?


    In the Mate PropertyManager, under Options, select Use for positioning only. Components move to the position defined by the mate, but a mate is not added to the FeatureManager design tree. You can move the component away from its position by dragging it or adding another mate to it.

    This option avoids potential mate errors because mates are not actually applied to the model.

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Answers: Changing, Deleting, or Suppressing Mates

  1. How do I change a mate?
    1. Expand the Mates folder in the FeatureManager design tree.
    2. Right-click one or more mates, and select Edit Feature.
    3. Edit the settings in the PropertyManager, then click PM_OK.gif.

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  2. Can I delete or suppress a mate?


    In the FeatureManager design tree, right-click a mate in the Mates folder and select Delete or Suppress.

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Answers: Mate Error Symbols

  1. My assembly has many yellow errors but my assembly looks fine. Why? What do I do?

    Yellow FM_Warning.gif usually indicates redundant distance mates only if no red errors exist. Yellow errors can also be caused by fixed components. Diagnose the problem using MateXpert and delete the redundant mates.

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  2. What's the difference between red and yellow errors?

    Red FM_X.gif = The mate is being violated. The parts are not in the positions specified by the mate. Another cause could be that the mate is dangling because one of the entities (face, edge, plane, etc.) is no longer in the model. Investigate red errors first.

    Yellow FM_Warning.gif = The mate is satisfied, but another mate (usually red) is trying to move the parts in a way that would violate this mate. Another cause could be that this is a distance mate that is redundant to other mates in the assembly.


    The left and right components are fixed. The blue component floats. A coincident mate, (Coincident1) is between the gray and blue blocks.

    When you add another coincident mate (Coincident2) between the blue and orange blocks:

    Coincident2 displays a red FM_X.gif mate error because the parts cannot move as this mate requires.

    Coincident1 displays a yellow FM_Warning.gif mate error because the red FM_X.gif mate error is trying to move the gray and blue components and violate Coincident1.

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  3. What's the difference between the (+) and (?) prefixes to components in the FeatureManager design tree?

    (+) = over defined

    Conflicting or redundant over defining mates exist. Delete or edit the mate causing the problem. The best practice is to fix over defined mates when they occur.

    (?) = not solved

    The SolidWorks software cannot solve the mating relationship. Consider deleting mates, moving components closer to the desired solution, adding more mates, or changing the mate scheme.

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Answers: Mate Errors

  1. An error message appeared after I added a mate. How do I fix mate errors?

    The fix depends on the type of error. Use Search or look in the Mates section of the Table of Contents to find help topics about specific types of mate errors and about tools (such as MateXpert, mate callouts, and View Mate Errors) that help you to identify and resolve mating problems

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  2. The mate or mate icon I want to add is not available. Why?

    Only the mates that apply to the current selections are available. For example, you cannot make a concentric mate to a planar face.

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  3. I have a redundant mate. How do I know what mate it is redundant with?

    Use MateXpert to identify redundant mates.

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  4. Can I purge redundant mates?


    You cannot purge all redundant mates. Use MateXpert to identify redundant mates.

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  5. My mating angle flips direction. Can I stop this from happening?

    If you have correctly set up the mates, this should not happen. Check the mate setup to make sure it correctly defines your design intent. Use Search or look in the Mates section of the Table of Contents to find help topics about best practices to use when creating mates. If the problem persists, report it to technical support.

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  6. There are mate problems when mirroring. What do I do?

    Use the Mirror Component PropertyManager to create mirrored assembly components that preserve mates between components. The MirrorComponent feature holds the mirrored components in position relative to the seed components with respect to the mirror plane. No other mates are needed to constrain the mirrored components.

    If you want to apply different mates to the mirrored components, right-click the MirrorComponent feature and click Dissolve Mirrored Component Feature. Then you can move and rotate the components and apply mates to them.

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