In this dialog box, you set the Z direction for the setup. This will correspond to the Z axis of your machining coordinates. If you are happy with the current Z direction, just click Next.
To change the direction of the Z axis:
To specify the Z axis with two points, select Pick two points to define Z direction and then click two points. The first point will be the tail of the vector and the second point will be the head.
To make the Z axis perpendicular to a surface of the model, select Align Z Perpendicular to horizontal surface and then select the surface.
To locate at the center of a revolved surface, select Align Z perpendicular with center of revolved surface and then select the surface. This technique is useful for locating the Z parallel to the axis of a hole or to the center axis of a turned, or indexed part.
To align the Z perpendicular to two lines, select Align Z perpendicular to plane defined by two lines, and then select each line.
To align perpendicular to a circle, select Align Z perpendicular to plane of a circle and then select the circle.
If the Z is pointing 180 degrees off of the desired direction, click the Reverse Z button.
Click the Next button.