Although many of you are probably familiar with various feature pattern creation techniques in 3-D CAD, you may not know that a pattern can be created along a curve or spline. A curve pattern creates instances of a feature along a sketched curve, and does not require equations if the number of pattern members is specified. If desired, pattern members can be skipped as well.

First Feature (Pro-E)

When creating a pattern along the curve in Pro-E, the first point must be on the end of the curve (zero offset).  If the first point is located some distance from the end, than the entire pattern will be offset from the surface body creating a “mirror” effect, by translating the start point of the pattern. If it is preferred that the first member of a pattern not be at the start of the curve, I will cover at the end of this post how resolve this problem.

Before creating a pattern along a curve, the pattern requires a surface for anchoring. This can be either a face(s) of a solid, or a surface body. The surface body can even be hidden so the pattern appears to float in space. For the first feature to be patterned, a datum point is created at the start of the curve, and a reference plane was created to control the orientation of the axis of revolution.  In this example, a solid feature (surface feature optional) is revolved about an axis from the internal sketch. An external sketch could have been used as well.

You can create a curve pattern by:

• Specifying the distance between the pattern members along the sketched curve.

• Specifying the number of pattern members, including the pattern leader along the curve.

Feature Pattern Tool (Pro-E)

This example specifies the number of pattern members, and the options “general” and “follow curve” are selected.  The numbers of instances are evenly spaced along the curve; hence the reason equations are not needed.  Also, one of the pattern members in this example is skipped by selecting clicking the black dot so that the color becomes white. The skipped member can be restored by clicking the dot again.

Returning to the topic of removing the first pattern member located at the start of the curve, use a copy surfaces (seed & bound), and a solidify (cut) to remove the first feature from the pattern.  From the photo, a ghost image of the copy feature is shown for clarity by highlighting the copied surface feature in the model tree.

For more information about creating patterns of features in Pro-E, refer to the help menu. I plan to follow-up in the future with a post on how to replicate this technique using SolidWorks. Hopefully, this technique will be useful to you in the creation of your 3-D CAD models.

Complete Pattern (Pro-E)