Arc of circle segment
Figure 12 shows the definition of the arc of circle segments. The radius and angle of rotation of the arc are required to define the segment. The origin point is the end point of the previous segment. The arc of circle centroid can be defined by the user or automatically positioned by the software. In the latter case, CADAM3D calculates the position of the centre such that the slope between the previous segment and the slope of the arc at the origin point are identical.
In addition, each segment is illustrated with a normal line following its creation. To initiate the arc segment's curvature in one direction or the other, the user must specify whether the arc segment retains the same normal direction as the previous segment. As shown in Figure below, the normal of segments 3 and 4 are in opposite directions.
The sign convention for the positive direction is displayed in the dialogue box and depends on the original planes, X-Y, X-Z and Y-Z (see Figure 12).