Circular sketch patterns allow us to pattern sketch entities in a circular direction. The following sketch highlights how we can define a circular pattern in SOLIDWORKS sketching:

In the preceding sketch, the shaded circle is the base circle, while the others are additions to be made with the pattern command. The annotations in red are the parameters that we need in order to communicate a pattern to SOLIDWORKS sketching. The following is a small description of the different annotations in the preceding sketch:

• Center: This represents the center of rotation for the circular pattern. This can be determined with specific x and y coordinates or by relating it to another point.
• Radius: This is the distance between the original entity and the center of the pattern.
• Angle: A1: This is the angle between two adjacent patterned entities.
• Total Angle: A1: This is the angle between the original and the last patterned entity.
• Number of patterned entities: This shows the total number of patterned entities, including the base sketch.

To illustrate how to use circular sketch patterns, we will create the following sketch. We will use the IPS measurement system in this exercise:

To sketch the preceding diagram, follow these steps:

1. Sketch and fully define the base entity, as shown in the following sketch:

2.  Select the Circular Sketch Pattern command from the Sketch command bar:

3. Select the three lines that form our base sketch. Now, we can set up our Circular Pattern using the options that appear on the left-hand side of SOLIDWORKS. Set the options that are shown in the following screenshot. As we are adjusting those options, a preview of the final shape will appear on the canvas. From top to bottom, the options we will be using are as follows:
   • Center: This field starts as Point-1 and represents the center of the pattern. By default, the center of the pattern will be the origin; however, we can change it by selecting other points. Rotational direction, which is to the left of the Point-1 selection, is a bottom that will flip the direction of the rotation.
   • X and Y center locations: The two fields marked with X and Y represent the location of the center of our circular pattern. Since our center is the origin, the location is marked as 0.00 inches for the X and Y directions. We can use these fields to set up an exact center in the coordinate system.
   • A1 Angle: This defines the angle that will govern the locations of the circular pattern. In our example, it is set as -180 since the pattern goes counter clockwise by 180 degrees. Note that this does not define the dimension; instead, it helps us approximate the location and the look of the pattern. We can fully define the pattern after its implementation.
   • Equal spacing: This will ensure that all the patterns are equally distributed in the angle range.
   • Dimension radius: This will add a driving dimension to the radius of the pattern. Note that this is not needed if we merge the center with a fixed point, such as the origin.
   • Dimension angular spacing: Checking this option will allow us to dimension the angle between the adjacent patterned instances instead of the angle between the base sketch and the last patterned entity.
   • Number of patterned instances: This indicates how many times we want the entity to be drawn or patterned, including the base sketch.
   • Display instance count: Checking this option will show the number of instances on the drawing canvas.
   • Radius: This allows us to linearly increase or decrease the radius between the patterned entities and the center.
   • A2 Angle: This will shift the center of the pattern so that it's at a certain angle.

Refer to the screenshot at the beginning of this subheading for a graphical representation of some of these options:

4. After adjusting these options, we can click on the green checkmark. This will give us the following shape. Note that the pattered entities are not fully defined. To understand how circular patterns work, we can click and drag the blue parts of the sketch around. We will see that the patterned shapes move together:

5. Set the angle between L1 and L2 so that it's equal to 180 degrees. Doing this will fully define the sketch, as shown in the following diagram:

Similar to linear patterns, we have the option of skipping instances, editing the circular patterns, and deleting instances. To do these things, we can follow the same procedure that we followed for linear patterns. 

This concludes this exercise of using circular patterns. In the exercise, we have covered the following topics:

• How to set up and define circular patterns
• The different options that we can use to define a circular pattern
• How the circular pattern entities interact with each other as under defined entities

Note that we can use both linear and circular patterns to build one sketch, but we have to use them one after the other. Now, we can start looking at another special sketching command—trimming.