Machining Shallow Passes reference

Avoid big cusps/steps in the steep areas.

The Machine Shallow Passes checkbox on the Passes tab for a pocket operation is used to avoid big cusps/steps in the steep areas. When using a fixed maximum stepdown, each Z-level is fully machined. However, when shallow passes are enabled the shallow Z-levels only machine the stock that remains after cutting the lower passes. The major stepdowns are always fully machined and the order of the passes is still top to bottom.

This approach ensures that the tool is fully utilized in the depth of the cut when possible. Also, machining time is reduced by not wasting time cutting stock that can be cut by passes below without exceeding the capabilities of the tool.

Pocket toolpath with shallow passes viewed from the side

The image above shows a pocket toolpath that machines around a core with two shallow Z-levels (next to the red dot). The orange dot indicates one of the major steps. In the image, the shallow passes do not clear the entire Z-level since they do not extend beyond the boundary of the part like the major steps.