Creating Tritangent Fillets

The creation of tritangent fillets involves the removal of one of the three faces selected, as the fillet surface is obtained by rolling a sphere, which radius is automatically computed to be tangent than the removed surface, between the selected surfaces.

This task shows you how to:

Before you begin: Create a 3D shape containing three surfaces
Related Topics
Creating Bitangent Shape Fillets
Creating Edge Fillets

Create a Tritangent Fillet

You can create tritangent fillet using the Tritangent Fillet command.

  1. Click Tritangent Fillet .

    The Tritangent Fillet Definition dialog box appears.

  2. Select the two Faces to fillet.

  3. Select the Extremities that is the relimitation mode:


    • Straight: no tangency constraint is imposed at the connecting point between the fillet and the initial support, generating sometimes a sharp angle.

    • Smooth: a tangency constraint is imposed at the connection between the fillet surface and the support surfaces, thus smoothing the connection
    • Maximum: the fillet surface is limited by the longest selected edge
    • Minimum: the fillet surface is limited by the shortest selected edge

    (Refer to Creating Bitangent Shape Fillets)

  4. Select the Face to remove.

    The fillet will be tangent to this face.

  5. You can check Trim support to relimit the support elements and assemble them to the fillet.

  6. Click OK.

    The faces are filleted. The creation of this fillet is indicated in the specification tree.

    Tip: While creating the fillet, you can limit it by selecting a surface that intersects it completely. This capability is available when clicking More>> and clicking within the Limiting element field prior to selecting the trimming element. For further details, refer to Creating Edge Fillets.
    Warning: Note that the selection of the feature prevails over the selection of the sub-element. To select a sub-element, you need to apply the ''Geometrical Element'' filter in the User Selection Filter toolbar. For further information, refer to Selecting Using A Filter in CATIA Infrastructure User's Guide.

Fillet Volumes

You can create fillets to volumes.

  1. Click Tritangent Fillet .

    The Tritangent Fillet Definition dialog box appears.

  2. Select the two Faces to fillet.



  3. Select the Face to remove.

    The fillet will be tangent to this face.

  4. Click OK to create the fillet volume.



    Warning: Extremities and Trim support are unavailable as they cannot be used with volumes.