About Dimension Patterns
When you create a Dimension pattern, you select feature dimensions and specify the incremental changes to these dimensions and the number of instances of the feature in the pattern.
Dimension patterns can be unidirectional (such as a linear pattern of holes) or bidirectional (such as a rectangular array of holes). In other words, bidirectional patterns place instances in rows and columns. You can select a plane (in which case the direction is normal to the plane), a straight edge, a datum axis, or an axis of the coordinate system as a dimension reference.
Depending on what dimensions are chosen to vary, patterns can be linear or angular.
When you create Dimension patterns, remember these tips:
• You can use a feature as a pattern leader for a single pattern only. After you create the pattern, the leader becomes part of the pattern and can no longer act independently.
• When you create a pattern leader, think of the dimensions you may need to specify the location of the increments. Keep in mind that for rotational patterns, a feature must have a built-in angular dimension. For other patterns, create a pattern leader with meaningful dimensions that will be used later to control the location and size of the increments.
• An angular dimension controlling a centerline of a sketched feature should not be used to establish an angular reference. Use an asynchronously created datum plane to set an angular dimension of the feature. Asynchronous datum features are automatically grouped with the feature. You can then create the angular pattern of this group.
• When you select the pattern type, consider the regeneration time. For simple patterns, use the Identical or Variable options to speed up the regeneration of the model.
• Use relations to control the location of instances when you expect the number of instances to vary. In this case, whenever you modify the number of instances, the system calculates the spacing according to the formula you entered.