Declaring Weight

You can either retrieve from the engineering bill of materials the declared weight of elements (parts, fake parts or assemblies) coming from a catalog or a sub-contractor, or declare the weight of an element manually.

Note: If the declared and the computed weight of a part are different, then the declared weight is taken into account.

This task shows you how to:

Before you begin: Open the assembly and start weight definition.

Retrieve the Declared Weight from the Engineering Bill of Materials

When applicable, you can retrieve from the engineering bill of materials (Engineering Central) the declared weight of an element (part, fake part or assembly) coming from a catalog or a sub-contractor.

When applicable, the corresponding BOM structure can be retrieved from the engineering bill of materials (Engineering Central) if you use this option:

  1. From the top bar, select Me > Preferences.
  2. Select the General > Parameters and Measure category in the left-hand box.
  3. Select the Take into account the weight declared on the synchronized EBOM part option in the Weight Management tab.

Note: For more information about the engineering bill of materials, see the Engineering Team BOM User's Guide.

  1. In the tree or in the work area, select an element for which you want to retrieve the weight from the engineering bill of material.
    An information message appears, displaying the weight of the selected element, retrieved from the engineering bill of material. A red lock is displayed in front of the weight to indicate that the value is locked and cannot be modified. A table appears, displaying the attributes of the selected element, retrieved from the engineering bill of materials:
    • The weight
    • The center of gravity (CoG)
    • The moments of inertia
    • The products of inertia
    • A comment
    Note: Once you have retrieved the declared weight of an element from the engineering bill of materials, you cannot remove this declared weight.
    Tip: You can switch from declared to computed weight by clicking Click this hyperlink to replace declared by computed weight in the information message.
  2. Optional: Select the Comment value cell, then click the value and enter a comment.

Declare the Weight Manually

When you know the weight of an element (part or assembly), you can declare it manually.

  1. In the tree or in the 3D area, select an element for which you want to declare the weight manually.
    An information message appears, giving you the choice between declaring or computing the weight of the element.
  2. Click Click this hyperlink to declare a weight on this element .
    A table appears, displaying the attributes of the selected element:
    • The weight
    • The weight error margin
    • The center of gravity (CoG)
    • The moments of inertia
    • The products of inertia
    • A comment
  3. Optional: Click Initialize to initialize inertia values (moments of inertia and products of inertia) according to the geometry.
    The inertia values are computed.
    Note: If you check the Initialize check button, the values are initialized depending on the geometry, making the weight and the inertia matrix values coherent. The following icons are displayed:
    • : the value is linked to another value.
    • : the value depends on another value. It cannot be edited.

    Modifying the weight automatically impacts the inertia matrix.

    Warning: If the Initialize check button is not selected, and if you modify the geometry or values such as the weight value once inertia values have been initialized, the app does not check the data consistency.
  4. Select the Weight value cell. Then click the value and enter the appropriate weight.
    Note: The default unit of measure is defined in Me > Preferences > General > Parameters and Measure, Units tab, Mass item.
    Important: When synchronizing for the first time in Engineering Central, the declared weight of the element is then retrieved in the engineering bill of materials. Once this is done, you are no longer able to modify the weight of the element in Weight Analysis.
  5. Optional: Select the Weight error margin value cell, then click the value and enter the error margin applicable to the declared weight.
    This margin is then taken into account when computing the global weight of the assembly.
  6. Optional: Select the Comment value cell. Then click the value and enter a comment.

Once you have retrieved the declared weight of the element from the engineering bill of materials, or declared the weight of the element manually:

  • The center of gravity of the element is initialized, taking the geometry into account.
  • The element turns to blue, indicating that its weight declaration is complete. If there are several instances of a part in the assembly, every instance of the part is also updated with the declared weight and turns to blue.
  • The assembly itself is updated to take the declared weight of the elements into account.
  • The tree is updated, reflecting the declared weight status of the element in the assembly using a blue rectangle to the left of the element's name.
  • The percentage of elements with declared weight is updated.