Autofilleting

The AutoFillet capability fillets the edges of a surface feature in only one shot. In case you need to fillet the whole edges of the surface feature, you just need to adjust the radius value according to your needs and then run the capability.
In case you do not want to fillet the whole surface feature, just select the faces to be filleted and optionally select what we call Functional faces: these faces identify the edges you do not want to fillet.

Using Autofillet is therefore a good way of drastically reducing the time spent on filleting.

Scenario

This section provides a scenario showing you how to use the capability through a representative example of autofilleting, then discusses the following topics:

Open the AutoFillet.CATPart document.

  1. Click Automatic filleting in the Advanced Operations toolbar.
    The Automatic filleting definition dialog box appears.

  1. Optionally, click More>> to expand the dialog box and display images helping you define your specifications.

  2. Select a support surface Surface.1 in the Support field to manage the feature which is to be filleted. This field is grayed out, if Faces to fillet, Functional faces or Slivers & cracks field is selected. By removing all specified faces, it becomes selectable again.

  3. The Selection Type field lets you specify a computation mode among two possible ones:

    • All Faces: the edges around all the faces of the support are filleted. In this mode, the Faces to fillet field is disabled. This is a default mode.
    • Faces selection:  the edges around the faces selected are filleted.

    Help images reflect the computation mode you select. For the purpose of our scenario, keep All Faces.

  4. Select the faces in the Functional faces field which you do not want to fillet. The selected faces turn purple, indicating that they will not be filleted.

  5. Keep 3mm as the radius value you want to assign to edges in the Fillet radius field.

  6. Select the Round Radius check box and define a radius to round convex edges.
    The icon on the right side of the field is modified accordingly.

  7. Select the Show curvature less than field to ensure that the application displays the fillets whose radius value is less than the smaller radius value you entered.
    Keep 2mm in the Show curvature less than field. Thus, in case the application generates fillets whose radius value is less than 2mm, a warning message will therefore be issued.

  8. Click Invert material side to reverse the orientation of the virtual material side.
    In this case, concave edges become convex and convex edges become concave.
    You can also click on the red arrow in the 3D area.
    This button only becomes available when the Round Radius option is selected.

  9. Check OK to confirm.
    A new dialog box appears, indicating the operation progress. In case you want to interrupt the operation, just click Cancel. Because the application detects fillets whose radius value is less than 2mm, a warning message is issued.

  10. To show the fillets, select the warning message from the Warnings window.

    The fillets are displayed in red in the geometry area.

  11. Click Close to close the Warnings window.
    The operation is complete. All the edges except for edges surrounding both functional surfaces are filleted. A new feature identified as AutoFillet.XXX is added to the specification tree. Compared with manual filleting, using AutoFillet is also a way of considerably reducing the number of features in the specification tree.

 

Non-filleted Areas

For different reasons, there might be cases where the system is not able to deal with all the edges to be modified. When this happens, the system does not stop at the first error encountered but computes as many fillets as possible and leaves the remaining edges untouched so that you just have to finish the job manually.

The application issues a warning message to help you identify non-filleted edges.

Slivers and Cracks

A sliver is an unwanted thin wall which should be smoothed and partially removed by the automatic filleting operation. A thin wall that is not rounded is not processed by the Autofillet capability unless you select it as a sliver.

A crack is an unwanted slot which should be smoothed and partially filled by the automatic filleting operation. Similarly, a slot that is not rounded is not processed by the automatic filleting algorithm unless you select it as a crack.

If you do not select them as slivers or cracks, thin walls and thin slots are filleted by Autofillet. The resulting height and depth of walls and slots are slightly decreased. Furthermore, the resulting curvature radius is less than the given fillet radius because of small thicknesses.

Managing Curvatures

Two capabilities are provided to help you obtain the best possible result:

  • The Preview capability provides a way of anticipating problems.
  • The Select slivers and cracks capability is available after clicking Preview. It automatically adds the slivers and cracks to the selection. Faces corresponding to slivers and cracks are displayed in green.

Using Preview

The Preview capability allows you to see the different areas where problems arise and therefore help you select the slivers and cracks to get the best possible result. Using Preview, you can see

  • in green the areas for which the operation will be done correctly. 
  • in red, the edges for which the application cannot modify the geometry correctly (i.e. with the good curvature).

Using Select Slivers and Cracks

Clicking on Select slivers and cracks automatically adds the slivers and cracks which are not yet selected and which are mandatory to run the automatic fillet correctly. Then you just need to click Preview again to obtain the next result: the lines are green, the problem is solved.

Limitations

  • Dedicated to casting fillets, Autofillet has been designed for robustness purposes rather than shape and curvature precision. Surfaces resulting from automatic filleting may not be as precise as those obtained using the traditional Fillet capabilities. Consequently, you should create design fillets on the feature before performing an automatic filleting.
  • The bounding edges of a smooth skin (a set of faces sharing smooth edges) are sharp. Autofillet instantly aborts if the input body contains any sharp edge whose bounded faces belong to the same smooth skin.
  • To be able to edit or update the geometry produced by AutoFillet, a GSO license is required. Otherwise, the only solution for being able to work on surface features containing AutoFillet features is to deactivate those features until edit or update operations can be achieved in a CATIA session with a GSO license.

  • The Autofillet feature is subjective to the presence of the GSO product license. A warning message is displayed indicating the limited use of this feature due to non-availability of GSO product license.

  • Automatic filleting may not work properly if input body already includes fillets with the same radius as automatic fillet input. In this case, a warning message is displayed after completion of the operation.