Using Variable Radius to Create a Fillet

The variable radius fillet provides several controls over the fillet along its edge path. You can choose to set radius values at specific points, or to use conic sections defined by parameter Rho. This feature is useful for complex geometry such as turbine blades.

1. To create a fillet:
   • Right-click on an edge in the 3D-CAD View window and select Create Fillet.
   • Click (Create Fillet) in the 3D-CAD toolbar. If the 3D-CAD toolbar is not visible, click Window > Toolbars and activate 3D-CAD from the list.
2. In the Fillet panel, select the Variable Radius option.
   
   

   

   
   
3. To add to the edge selection, click within the Connected Edges box, press and hold the <CTRL> key and select further edges in the graphics window.
   Edges must to form a single connected chain on a single body. For closed loop edges, you must define two points on the edge.
4. To remove one or more edges, right-click on selected edges in the list and choose the corresponding action.
5. Set Fillet Shape to either Circular or Conic.
   To achieve a particular type of conic shape, alter the Rho value as follows:

   • Elliptic: 0 < Rho < 0.5
   • Parabolic: Rho = 0.5
   • Hyperbolic: 0.5 < Rho < 1
6. If the feature fails, then adjust the tolerance value. The tolerance value is based on the size of the input entities. For example, if an edge is 0.1 mm long on a small geometry, a high tolerance will completely ignore or eliminate the desired details in the model.
7. To define additional locations on which to set the radius:
   1. Click the Add Points On Edges option.
   2. In the Graphics window, click the approximate location along the target edge.
      A blue color point appears on the edge to show the location of the control point.
      

      

      
      
   3. Continue to create points on the target edge by clicking on the approximate locations.
   4. In the Fillet panel, select the points individually and set their precise relative positions along the edge. Within the Fillet Location group box, you can use the slider or else enter a value directly within Position Along Edge.
      The following screenshot shows the control points in the table and their position on the target edge.
      

      

      
      
   5. In a similar manner, select each point in the table and enter its Radius value. In the Fillet Location group box, the Variable Radius entry is the same property as the Radius entry in the table.
      
      

      

      
      

If you define a control point along an edge, but wish to check how the fillet looks without it, then you can deactivate the control point without deleting it.

8. To remove the influence of a control point on the fillet, in the table of points, do one of the following:
   • Deactivate the Active property next to the point.
   • Right-click either the Point Name, Edge Parameter, or Radius column of the required table row and select Deactivate.
   You can reactivate points in a similar manner.
   
   

   

   
   

Clamping allows you to impose a zero rate of change of radius on the fillet as it passes through a chosen point. Clamping is valid on start and end points as well as intermediate points.

9. To apply clamping to a point, select its row in the point table and activate Clamp.
   The right-click menu on a Point Row, Edge Parameter, or Radius column provides the same option.