In the Spring 1999 issue of Pro/files, Gerry Champoux demonstrated a way of representing large patterns. This technique differs in that it actually produces the final geometry rather than a representation using surfaces or datum curves.

When creating large patterns of holes or openings—on the order of several thousand instances where the final geometry of each instance is made up of several features—regeneration time can sometimes take hours.

The main reason is that, while the first feature is patterned as an identical pattern, the remaining features are typically done as reference patterns. Reference patterns are automatically created as general patterns, which have the longest regeneration time. The key is thus to reduce the number of reference patterns in the part by using surfaces to create the openings.

The vast number of holes or cuts being made in the part also adds to regeneration time. This shortcut, however, uses surfaces or quilts transformed and patterned to replicate the openings. Hundreds or even thousands of quilts are then merged into a single quilt that is used to make the cut. In this way, a single cut adds all the openings to the part at once, which is much quicker than adding each one individually.

The part shown below will be used to illustrate the technique. The openings are made up of six features—a through hole, a round, two blind cuts, and two chamfers.

1. Create the parent geometry.

Create the initial part geometry as you normally would with a single opening positioned in the correct location.

2. Make a surface copy of the geometry.

Create a quilt that is made up of all the surfaces of the opening using the seed and bound surface gather method.

See a comparison of regeneration times using this method versus the traditional method