Current Help System: PC-DMIS CMM (View Core Help)

## Creating an Auto Polygon

The Polygon dialog box lets you define and insert a Polygon auto feature into your part program. A polygon is any feature composed of three or more sides of equal distance. For example, hexagon or octagon shapes are both polygon feature. This auto feature is primarily used to measure nuts and bolts.

An Example Polygon Auto Feature

To define and insert a Polygon option, access the Auto Feature dialog box for a Polygon (Insert | Feature | Auto | Polygon).

Auto Feature dialog box - Polygon

With the dialog box open, depending on your situation, use one of these methods to create the feature:

Creating by Using the CAD Model

1. Access the Polygon auto feature dialog box (Insert | Feature | Auto | Polygon).

2. In the Number of Sides box, define the number of sides of your polygon feature has.

3. Click once on the desired polygon feature in the Graphics Display window. PC-DMIS fills in the center point information for the polygon and draws some preliminary path lines. As you make changes to the dialog box, notice that PC-DMIS dynamically updates to path to reflect the changes.

   Preliminary path lines displayed, showing 2 hits per side

4. In the Number of Hits box, define how many hits you want PC-DMIS to take when measuring each side. PC-DMIS will always take at least two hits on the very first side of the feature to determine the feature's angle vector.

5. In the Orientation area, determine whether it's an inner polygon or an outer polygon by selecting Hole or Stud respectively.

6. In the Corn. Rad. box, define a corner radius. This determines how far away from the corners PC-DMIS should take hits on the polygon sides. This helps avoid taking hits directly in the corners.

7. In the Diameter box, ensure that you have a correct diameter for the polygon. For common, even-sided polygons, the diameter is the distance between two opposing sides. For other polygons, such as an equilateral triangle, it is twice the radius of the largest circle you can inscribe inside the polygon. PC-DMIS automatically fills in this value when you click on the polygon.

8. Make any other modifications to the dialog box and the Probe Toolbox as needed.

9. Click Create. PC-DMIS inserts the Polygon auto feature into your part program.

Creating by Using the CMM:

You can "learn" an Auto Polygon's position without using any CAD data by simply taking hits on the part with your machine's probe. Fill out the dialog box with the necessary information. With the Polygon Auto Feature dialog box remaining open, take a hit on one of the polygon's sides. After the first hit, the Status Bar at the bottom of your screen will provide you with additional instructions. Follow the prompts given in the Status Bar to complete the polygon creation. Click Create when finished.

Creating by Keying in the Data:

If you know the theoretical data for the polygon, you can also create a polygon auto feature by simply typing in its theoretical data in the appropriate fields. Using the Polygon auto feature dialog box, specify the XYZ center and IJK vector information. Define the number of sides, the number of hits per side, the diameter, and the corner radius. Click Create when finished.