Creating the Top Fillet

The top fillet will link the bonnet to the inlet walls. We know that it has a radius of 2mm, as this was measured from the original triangle model.

First, we need to create a composite curve around the internal trim curve of the bonnet surface. We will then create the fillet surface.

To create the top fillet:

1. Click on the ISO 1 button , so that you can see the surfaces clearly.
   
   
2. Click on the Zoom to Box button , then click and drag to zoom in on one of the inlets.
   
   
3. Hold down the Alt key and click on the edge of one of the bonnet's internal trim boundary.

A composite curve is created around the boundary, marked by a yellow line with blue points.

Tip: It is easier to pick the internal trim curve if just the bonnet surface is displayed.

To blank the extruded surface, click on it and press Ctrl-J.

When you have created the composite curve, unblank the surface by pressing Ctrl - L

4. With the composite curve selected, click on the Surface button on the Main toolbar.
   
   
5. Click on the drop-down button next to the Surface option list to display the available surface types.
   
   
6. Click on the Fillet Surface button .
   
   
7. Click on the extruded wall surface to select it.
   
   
8. In the Fillet Surface dialog box, change the following values:
   • Fillet Radius = 2
     
     
   • Convex option = selected

The Selection area shows that the Primary selection is Surfaces (the extruded wall) and the Secondary selection is Wireframe (the composite curve).

9. Click on the Preview button to see what the fillet will look like.
   
   
10. If it is wrongly oriented, as shown in the example below, locate the arrow on the composite curve and click on it to reverse the curve's direction.

11. Click on the Preview button again to check the fillet surface, then click on the Accept button to create a surface like the example below.

12. Repeat the steps to create a fillet around the top of the other inlet.

Next:

Creating the Bottom Fillet