Page 277 - Mastering SolidWorks

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understanding Fillet tyPes 249

You can select the hold line in the Fillet Options panel of the Face Fillet PropertyManager. The
top panel, Fillet Type, is available only when the feature is first created. When you edit it after it
has been created, the Fillet Type panel does not appear. As a result, you cannot change from one
top-level type of fillet to another after it has been initially created.

Using a Double Hold-Line Fillet
Sometimes, a single hold line does not meet your needs. The single hold line controls only one
side of the fillet, and in order to control both sides of the fillet, you must use a double hold-line
fillet. SolidWorks software does not specifically differentiate between the single and double
hold-line fillets, but they are radically different in how they create the geometry. When both sides
of the fillet are controlled, it is not possible to span between the hold lines with an arc that is
tangent to both sides unless you were careful about setting up the hold lines so that they are
equidistant from the edge where the faces intersect. This means that the double hold-line fillet
must use a spline to span between hold lines, as shown in Figure 7.36.

Figure 7.36
a double hold line uses a Arc Spline
spline cross section, tangent on tangent
not an arc. both ends on both
does not fit ends fits
both edges

To get this feature to work, you need to use the Curvature Continuous option in the Fillet
Options panel. Remember that this option creates a spline-based fillet rather than an arc-based
fillet, which is exactly what you need for a double hold-line fillet. This makes the double
hold-line fillet more of a blend than a true fillet. This requirement is not obvious to most users
and may not even be documented in the SolidWorks Help, nor is it exactly intuitive. To get the
double hold-line fillet to work, you must use the Curvature Continuous option. Figure 7.37
shows examples of the double hold-line fillet.

Using a Constant-Width Fillet
The Constant Width option of the Face Fillet PropertyManager drives a fillet by its width rather
than by its radius. This is most helpful on parts where the angle of the faces between which you
are filleting is changing dramatically. Figure 7.38 illustrates two situations where this is particu-
larly useful. The setting for constant width is found in the Options panel of the Face Fillet
PropertyManager. The part shown in the images can be found in the download material as
Chapter 7 Constant Width.sldprt.