To Create a Coordinate System Centered on an Arc
1. Click > . The Coordinate System dialog box opens.
2. To define a reference for the first coordinate system axis, select a circular arc (curve or edge).
3. In the Coordinate System dialog box, next to the reference, select Center from the list.
◦ The origin of the coordinate system coincides with the center of the arc.
◦ The z-axis of the coordinate system is parallel to the normal vector of the plane that contains the circular arc. To change the axis, click the Orientation tab, and select a different axis.
1. Arc
2. Coordinate system z-axis coincides with the center of the arc and is normal to the plane that contains the arc
4. To define a reference for the second coordinate system axis, click the Orientation tab, click the second Use collector, and then select a reference.
5. Select an axis from the to project list.
6. Click OK.