Pocketing & Islands

An island is an area which the cutting tool will avoid when machining the selected pocket area. The tool will cut around each island in the pocket as closely as it can. If the Finish Pass (only Zig-Zag cycle) option is turned ON, the tool returns and makes a finishing contour cut around the pocket itself and each of the islands.

There are two ways to define islands when machining pockets. First is to include (append) the island profiles directly into the path curve selected for machining in the Path ID list box. Second is to create individual curves for every island and to add them as check curves in the Check Curves table on the 3D Cycle Data tab  of the Work Step Data dialog.

 

Rules for Boundary + Islands in single Curve (Mill, TurnMill):

  1. The pocket boundary and each included island must represent a closed shape.

  2. The boundary may start with a rapid move to define the plunge location ( see Plunge Point Control ).

  3. There is no rapid move within the boundary or the islands profiles allowed.

  4. The first defined contour in the curve is the boundary profile, followed by the islands profiles that are appended. The first island is rapid-linked to the pocket boundary and each successive island rapid-linked to the island before it.

  5. Islands may overlap each other, also they may overlap the boundary path.

    Click here for graphic Example
     

  6. A circular curve must contain at least three points (two arc elements).

 

Graphic example: Pocketing & Single Island

Graphic example: Pocketing & Multiple Islands

 

 

Rules for Boundary & Islands as individual Curves (Mill, Mill-Pro):

  1. The pocket boundary and each island are defined as individual curves, each representing a closed shape.

  2. The boundary may start with a rapid move to define the plunge location ( see Plunge Point Control ).

  3. There is no rapid within the boundary or the islands profiles allowed.

  4. Boundary and Island curves may not end with a rapid move.

  5. A circular boundary / island curve must contain at least three points (two arc elements).

  6. Island curves may overlap each other, also they may overlap the boundary curve.

Graphic Example: Pocketing & Islands (Islands as Check Curves)

Check Curves

 

 

Boundary & Islands Profiles on individual Z-Levels:

For the 2,5-D Pocketing and Zig-Zag operations it is possible to define the boundary and island profiles on different Z levels. If the pocket profile and boss profiles are defined at different Z-heights, the system automatically identifies which profiles are valid at different Z-levels of roughing. You can even include another boss or sub-pocket on top of a bigger boss. The cutting depth of certain steps is then adjusted accordingly, meaning the system reduces step size when necessary in order to machine the top-area of an island. Then it continues with full step size until subsequent islands or final depth (Z level of boundary) is reached.

  1. The pocket boundary and each island can be defined as single or individual curves (as already mentioned above)

  2. The boundary curve is positioned at the final pocket depth while islands are located on their desired Z levels above the boundary.

  3. Define "0" as machining Depth since the pocket depth is derived from the boundary curves Z level.

Graphic Example: Pocketing & Islands on different Z Levels

 

 

Important !

There are restrictions to the maximum number of islands depending on the way they are defined. If "Check Curves" (see 3D Cycle Data Tab) are used, there's a limitation of max. 100 islands (separate curves) for all cycles. If the islands profiles are appended (included) to the boundary curve, the Pocketing cycle has no limits, while Zig-Zag is limited to 1000 islands.