Creating a Mechanical Interface

You can create a basic mechanical interface without creating a template or instantiating it.

When you create a mechanical interface, an implicit compatibility rule is generated on its own that checks compatibility based on the kinematic joint that you specify.

Before you begin:
  • You must be an author to perform this task.
  • Open a 3D shape representation.
  1. From the Functional Tolerancing section of the action bar, click Mechanical Interface Creation .
    A Mechanical Interface node is added to the tree under the Interference Set node. This node contains a mechanical interface axis system node Mechanical Interface.x_Axis, which is also created and displayed in the 3D area.
  2. Under Characteristics, enter the Name and type of kinematic joint in the Joint box of the feature.
    The degree of freedom is shown in the 3D area using the mechanical interface axis system. The directions in which motion is allowed is represented in green color.

    Table 1. Representation of the various kinematic joints
    Kinematic Joint Type Representation in the Work Area
    Spherical

    Cylindrical

    Planar

    Prismatic

    Revolute

    Universal

    Screw

  3. Select the Position mode.

    • Geometry driven: Lets you define the primary, secondary, and tertiary geometrical elements defined under Set in position of the Positioning Geometry section used for positioning to make the engineering connection.
    • Axis system driven: Defines an existing external axis as a reference for positioning to make the engineering connection. If the axis system is edited or deleted, the instance is directly effected or rendered invalid. The Positioning Geometry section is disabled when this mode is selected.
    • Editable: Lets you define the inputs for the definition of a new axis system to be used later for positioning. Click to open the Axis System Definition dialog box, define the new axis system , and define the geometrical elements defined under Set in position.

  4. Select the Mounting attribute of the template as Moving or Receiving.
  5. Under Positioning Geometry, define the positioning of the feature.

    The geometrical elements control the positioning of the feature. These elements can be selected under Set in position and Maintain in position. That is, you can select the elements which will locate the position for the feature and then select other elements to restrain the feature in this position. This ensures a perfect engineering connection in the later stage of design.

    1. To define the elements under the Set in position section, click Primary and Ctrl + select the elements of the feature in the 3D area.

      Tip: Select anywhere in the work area to clear the selection of elements.

    2. Select the type of feature of this primary element in the Feature type box, if not automatically computed.

      Click to specify the geometry canonicity and its feature of size.

      When you specify the canonicity or feature of size and the selected feature type is not applicable, an icon appears for invalid feature type. You can select the valid feature type proposed in the Feature type list.

    3. In the Clearance list, select the type of clearance between the mechanical interface entity and the component.

      Note: Different clearance options are available for different types of geometries.

    4. Similarly, select the geometrical elements for Secondary and Tertiary with their feature types.

      You can select the secondary elements only after selecting the primary elements and the tertiary after selecting the primary and secondary.

      Table 2. Example: Set in position for a Key
      Geometrical Elements Selected in 3D and Their Preview in the Dialog Box Appropriate Feature Type Selected in the Feature type List
      Primary elements

      		1 slot/tab
      Secondary elements

      		1 plane
      Tertiary elements

      		1 cylindrical slot/tab

      Selecting all the Set in position elements enables the selection of elements in Maintain in position.

    5. Select the elements in Maintain in position.

      As you select the elements, a preview is shown within the dialog box. Select anywhere in the work area to clear the selection of elements.

      Note: Add the following supplemental geometries to completely define the primary surfaces, the secondary surfaces, the tertiary surfaces, and the maintain geometry surfaces:
      • Offset: You can add offset surfaces to the primary, secondary, and tertiary surfaces. To add an offset surface, select Offset or Aligned with Offset, in the Clearance list. The offset can be shared by two different entities in the same mechanical interface.
      • Extended surfaces: You can extend only the cylindrical surfaces to create connections inside an assembly. To add an extended surface, select Pin Tightening and Extension or Thread and Extension in the Clearance list. You can create multiple extended surfaces for a single mechanical interface.
      • Restricted area (or partial surface): You can select existing restricted area features for a mechanical interface entity. For more information, see 3D Tolerancing & Annotation User's Guide: Geometry and Annotations: Creating a Restricted Area.

  6. Under More Characteristics:
    1. Enter the type of the template in the Type box.
    2. In the Nature box,

      1. Select one of the following options available in the list:
        • Male
        • Female
        • Neutral
      2. Enter a user defined nature type.
      Important: Two basic interfaces are compatible to each other if the following two conditions are fulfilled.
      • Two interfaces have the same Joint type.
      • Following table lists different possible pairs of compatible nature types for mechanical interface templates.
        Nature Male Female Neutral Nature1
        Male
        Female
        Neutral
        Nature2

        The compatibility between user defined nature types (Nature1 and Nature2 in the table) must be defined in the business rules.

  7. In the Min and Max boxes, select the minimum and the maximum connections.

    These numbers indicate the minimum and maximum number of times this mechanical interface template can be instantiated. These numbers have to be positive non-zero numbers with the minimum number less than or equal to the maximum.

  8. Optional: Click Flip XY, Flip YZ, orFlip ZX, to change the orientation of the axes.

A basic mechanical interface is created. You can now make the engineering connections using the interfaces.