Working with 3D Tolerancing

This task makes use of the Electrical Harness workbench integration together with the 3D Tolerancing and Annotation product. It lets you easily define and manage 3D tolerance specifications directly on the 3D or flattened harnesses.
This allows the user to add dimension information directly to the 3D mock-up so that they are available for downstream process. For example, the contents of the 3D session can be sent to a harness supplier for manufacturing purpose and the dimensions to be respected will be part of the data provided.

Curvilinear Dimensions makes it possible to measure the distance between:

  • Two connectors of a geometrical bundle through multiple bundle segments
  • Two supports
  • A connector and a protective covering
  • A branch point and a connector, etc.
A Product Functional Tolerancing & Annotation license must be available to perform this scenario.
Refer to the 3D Functional Tolerancing & Annotation User's Guide for more information on the product.

You can use the following sample: ...\online\/cfysm_C2\/samples/\ElectricalAssembly/\ElectricalAssembly.CATProduct

  1. Select Start > Mechanical Design > Product Functional Tolerancing & Annotation workbench.

  2. Select Front View/Annotation Plane .
    Select a plane or an axis system to define the annotation plane.
    Here the horizontal plane for example.

    The Front View is added to the specification tree.

    Note: To better visualize curvilinear dimensions, set the viewpoint perpendicular to the annotation plane. To do so, click Normal View and select the annotation plane of interest.

  3. Select Curvilinear Dimensions in the Dimensions toolbar.
    You are prompted to select the first element for the dimension creation.

    • In the context of the Electrical Harness product, you can select a plane, a point or a spline.

    • Whatever the number of elements, at least one spline must be selected.

    • They must be ordered from one end to the other.

    • They must be in an electrical part (connector, equipment, bundle segment, support, back shell, protective covering, etc.)

    • The electrical continuity between the different elements selected is mandatory.
    For more information about this command, refer to 3D Functional Tolerancing & Annotation User's Guide - Basic Tasks - Creating Annotations - Creating Curvilinear Dimensions.

  4. Select for example: a connector face, two splines and a support face to delimit the second spline.

    • The connector face:
    • The first spline:
      Note that at that time:
      • The new feature appears in the specification tree (xxx.Part for Construction Geometries)
      • The dimension is previewed. By default, the dimension line is linear.
      You can switch to other visualization modes:
      • Right-click the dimension line to display the contextual menu.
      • Select Parallel.
        Refer to 3D Functional Tolerancing & Annotation User's Guide - Basic Tasks - Creating Annotations - Creating Curvilinear Dimensions to see the different view option.
      Optionally, you can drag the dimension line and/or the dimension value to position them as wanted.
    • The second spline:
      The dimension line is updated.
    • The support face to delimit the second spline:

  5. Click in the free space to validate and end the dimension creation.

    The dimension appears in white.
    The semi-arc symbol displayed over the dimension value symbolizes a curvilinear length dimension. You can now handle the dimension just like any other dimension.

User Interface Behavior

Selection of a 3D curve:

If the user selects a 3D curve of a branchable bundle segment, then the curvilinear length dimension will be displayed in the geometry area, and the user will have to click in the free space to validate the dimension creation and to exit the command (no other geometric selection will be proposed).

Selection of the first 3D curve after the selection of a starting point or planar face:

If the user selects a point or a planar face, he will then be prompted to select a harness routing spline.

Selection of other 3D curves:

Then the user will be prompted to complete the selection of harness routing curves or to select the ending point or planar face of the curvilinear length:
If the user selects another curve, the software will check the consistency between the curves. If the last selected and the new selected curves are not connected, an error message will be displayed and the last selection will be removed. The user will again be prompted to complete the selection of harness routing curves or to select the ending point or planar face of the curvilinear length.

Selection of an ending point or planar face:

If the user selects a point or a planar face, the curvilinear length dimension will be displayed in the 3D and the user will have to click in the free space to validate the dimension creation and to exit the command (no other geometric selection will be proposed).

Associativity

If an object taking part in the curvilinear dimension is moved in the 3D geometry area, the annotation is updated.

Electrical continuity

It is not possible to create a curvilinear dimension for bundle segments belonging to different geometrical bundles.

If you select points or planes, CATIA will find the best solution to compute the length the user intends to annotate:

  • Selection of a point:

    • On the bundle segment centerline: this point will be used as an extremity of the annotated length.

    • On a support: the projection of the point on the bundle centerline will be used as an extremity of the annotated length.

    • On a connector: a straight line will be added to this point from the bundle centerline extremity.

  • Selection of a plane:

    • On a support: the intersection point between the plane and the centerline will be used as an extremity of the annotated length. If the selected plane does not intersect with the centerline, the plane is ignored.

    • On a connector: a perpendicular line between the bundle centerline extremity and the plane will be added.

Creating Text or a Flag Note with Leader
When creating text or flag notes with leaders, create a point on the bundle segment curve to locate the leader. This ensures the associativity between the annotation and the bundle segment whatever changes are subsequently made to bundle segment shape.