Creating Variable Bi-Tangent Circle Radius Fillets
Using a Spine

This task shows how to create a variable bi-tangent circle radius fillet on an edge or consecutive edges that do not present any tangency continuity. The propagation along the edge(s) can be done smoothly when selecting a spine along which an arc of circle is slid. Cutting the resulting fillet surface by a plane normal to the spine would result in a circle of the specified radius value.

Using this type of radius may help solve twisted fillets created when using any other type of fillet.

Open the FilletVariableRadius2.CATPart document.
To find out more on variable radius fillets, refer to Variable Radius Fillets.
  1. Select the edge(s) to be filleted.

  2. Click Variable Fillet .

    The Variable Radius Fillet Definition dialog box appears.
  3. Click Preview.

    The fillet is previewed on the geometry.
  4. Change the radius value to 50mm.

  5. Click More>> to expand the Variable Radius Fillet definition dialog box and check the Circle Fillet option:

  6. Select the line as a spine.

  7. Click OK to create the variable fillet.

    The surface (identified as is added to the specification tree.
    The same operation without checking the Circle Fillet option would have led to the following fillet:
    • You can use any curve as a spine, provided it covers all selected edges, i.e. it is longer than the set of selected edges.
    • In some cases, fillets may be overlapping. Trim ribbons lets you solve this by trimming the fillets where they overlapping. For further information on this option, refer to Trimming Overlapping Fillets.
    • Click More>> to display further options: