Pocketing

Pocket tool paths are used to remove excess material. An example of a spiral pocket with helical entry is shown in Figure 7.10. CDC is not active during the roughing cuts, but may be used for finish passes on walls.

Figure 7.10: Pocketing

Rules for Pocketing

• Rough passes should leave a constant thickness of material on the walls and floor of the pocket to be removed by the finish passes.

• Consider using a roughing end mill to remove most of the material. These serrated mills can remove material at a far faster rate than finish end mills. They do leave a poor finish on the floors and walls that must be finished with a separate finish tool and operation.

• Helical moves are a good method for entering a pocket. If space does not allow a helical entry, use a center-cutting end mill or plunge the tool through an existing hole, or a pilot hole created for this purpose. The pilot hole must be at least 50% of the tool diameter.

• Spiral pocketing paths that start near the center of the pocket and move outward in a counter-clockwise direction are best because they cause the tool to continually climb cut.

• Use CDC only on finish passes.