Constant Z Machining without Path Curve

The graphic below shows a surface consisting of three peaks, with the Constant Z tool path applied at one Z level only (for graphic clarity). In this particular case, the absence of a Path ID (acting as boundary curve) yields an incorrect tool path which is below the surface. The system uses the cross section of the surface at the shown Z level to calculate the pocket boundaries, yielding six separate intersection lines where the surface crosses the Z level. These separate lines do not form a closed boundary, and so the system connects the endpoints to form three separate pockets. Unfortunately, in this case, the pockets end up being below the surface we intended to machine. The solution is to specify a pocket curve (Path ID) which surrounds the entire surface, but does not touch it. See Constant Z Machining with a Path ID.

Note in the case below that if we delete an S-curve from both ends of the surface, we would end up with a W shape surface. This would generate a correct tool path on top of the surface without using a pocket curve. This occurs because the cross section of the surface now yields four unconnected lines instead of six; when the system connects them, two pockets on top of the surface would be created.

Click here for graphic Example