Chapter 7: Selecting Features
Several features that carry the curve name are actually sketch-based features:Equation Driven Curve............................................................................................
l (^) Intersection curve
l Face curves
Tip
When you come across a function that does not work using a curve entity, but that works on a sketch (for
example, making a tangent spline), it may help to use the Convert Entities function. Converting a helix into a
3D sketch creates a spline that lies directly on top of the helix and enables you to make another spline that is
tangent to the new spline.n
You can define the following types of curves in SolidWorks:
l Helix/tapered helix/variable helix/spiral
l (^) Projected curve
Making Curve Through XYZ Points .........................................................................
l (^) Curve through reference points
l Composite curve
You can find all the curve functions on the Curves toolbar or by choosing Insert ➪ Curve from the
menu.
Curve features in general have several limitations, some of which are serious. You have to be pre-
pared with workaround techniques when using them. When curves are used in features, you often
cannot reselect the curve to re-apply sketch broken sketch relations. (The work around for this is
to select the curve from the FeatureManager, or if that doesn’t work, you have to delete the feature
and re-create it). In addition, curves cannot be mirrored, moved, patterned, or manipulated in any
way. (A workaround for this may be to use Convert Entities to create a sketch from the curve.)
Working with helix features
The helix curve types are all based on a circle in a sketch. The circle represents the starting location
and diameter of the helix. Figure 7.21 shows the PropertyManagers of the Constant Pitch and
Variable pitch helix .......................................................................................
You can create all the helical curve types by specifying any combination of total height, pitch, and
the number of revolutions. The start angle is best thought of as a relative number. It is difficult to
predict where zero degrees starts, and this depends on the relation of the sketch plane to the
Origin. The start angle cannot be controlled outside of the PropertyManager, and cannot be driven
by sketch geometry. The term pitch refers to the straight-line distance along the axis between the
rings of the helix. Pitch for the spiral is different and is described later.