Variable Size Fillets in SOLIDWORKS

Variable size fillets are a common tool used inside of the SOLIDWORKS modeling environment. We will go through some of the different options available when creating variable size fillets as well as how to create them.

As you may expect, Variable Size fillets are simply fillets that are created with a non-constant radius that varies along a single edge. Variable Size fillets share many options with Constant Size fillets but are defined in a much different manner.

Control points are created along selected edges to define the radius values of the fillet at that point. By default, a control point is created at the beginning and end of a selected edge and more control points can be added to the edge at specified locations for greater control over the fillet shape. These extra control points can be created by clicking on the edge or by holding the Ctrl key and clicking and dragging an existing point. Position values will appear as percentages along the selected edge to display how far along the edge the control point lies.

Below is a picture of a Variable Size fillet with only two control points starting with a radius of 10mm and ending with a 30mm radius (one at the beginning and end of the original edge).

Here is the same part with 3 extra control points added at 25%, 50%, and 75% of the edge length with values of 10mm, 20mm, and 25mm respectively.

The percentage values of the control points can be adjusted by selecting the percentage values straight from the graphics are or from the property manager on the left-hand side. You can also click and drag the control points to your desired location and the percentage values will update accordingly.

When using advanced fillet profile options with a Variable Size fillet, constant values can be used to define a profile, or they can vary along the edge. There are two ways these variable fillets transition from one radius value to another: straight or smooth. This is a setting that is available in the Variable Radius Parameters section of the property manager when creating this kind of fillet. Below a smooth transition is shown in red and a straight transition is shown in blue (both starting and ending radius values are the same for both fillets).

For even more information and practice with Variable Size fillets please look into taking the SOLIDWORKS Advanced Modeling course.