Automatic Boundaries

The Automatic Boundaries option is displayed for the Finish procedures, when picking Part Surfaces. To enter part surface selection mode:

Either press the button in the Work Mode Dialog (if you are in Wizard Mode), or display the Geometry parameters in the parameter tables.
The Geometry Table is displayed:

To start picking the required geometry, press the numbered button adjacent to the Part Surfaces geometry parameter. This button displays the number of part surfaces that have already been selected. You are then prompted to pick the required geometry.
See Selecting / Unselecting Geometry.
See the cursor symbols in Cimatron when picking geometry.

Automatically create boundaries to define the edges of the part faces. The Automatic Boundaries On/Off option is available while selecting surfaces to finish machine. It allows the system to consider either the outer, inner, or both outer and inner perimeters of all selected surfaces as a limiting contour for the cutter path. The system automatically defines those edges which can be manually modified, if required. When these boundaries have been defined, the system knows that the machining is to be done exactly up to these edges.

Automatic Boundaries and the exact location of the relevant edges are essential for the prevention of Waterfall motions and also for the Horizontal Machining Expansion calculations (for overlaps and extensions).
Example:Example:

Automatic Boundaries = OFF:	Automatic Boundaries = ON:
Note the 'waterfall' motions at both ends, as well as in the holes and gaps.	The 'waterfall' motions no longer exist.

Notice that some of the outer motions waterfall into the surrounding fillet faces.	The result is 'waterfall' free motions.

Horizontal Machining Expansion is created ONLY where Automatic Boundaries exist. The example image below shows a case where the Automatic Boundary is open on the right side. The result at this area is 'waterfall' motions which roll around the face edge and gouge the part.
Example:Example:

In the example faces below, note that there are several faces. Between some of the faces there are gaps and two of them are even overlapping each other.

When the Automatic Boundaries option is ON, colored contours appear around the outer edges of the selected faces and around the holes. These are the Automatic Boundaries.

The Automatic Boundaries define the edges of the part faces, and using this definition, the system knows that the machining is to be done exactly up to these edges.

If these faces are selected individually, the automatic boundaries are updated on-the-fly and the preview is automatic, as shown below.

The greater the number of faces (especially if there are numerous gaps and overlapping between the faces), the greater the amount of time required for the automatic calculation of each face. If the calculation time exceeds 3 seconds, then the Preview mode changes from Automatic to Manual.

Parameters displayed for the Finish procedures, when picking Part Surfaces:			Parameters displayed for all other procedures when picking surfaces.

When Automatic Boundaries = ON, additional parameters are available enabling you to modify the automatic boundaries, if required.

Faces Boundaries, Outer Only

Create automatic boundaries around the selected faces according to one of the following dropdown list of options:

Faces Boundaries, Outer Only

Create the automatic boundaries around the outer boundaries of the selected faces. With Outer Only, the result is 'waterfall' motions in the holes but not at both ends and the gap.
Example:Example:

Automatic Boundaries = Outer Only:	Result:

Faces Boundaries, Inner Only

Create the automatic boundaries around the inner boundaries of the selected faces. With Inner Only, the result is 'waterfall' motions at both ends and gap, but not in the holes.
Example:Example:

Automatic Boundaries = Inner Only:	Result:

Faces Boundaries, Outer and Inner

Create the automatic boundaries around the outer and inner boundaries of the selected faces. With Outer and Inner, the result that the 'waterfall' motions no longer exist.
Example:Example:

Automatic Boundaries = Outer and Inner:	Result:

A group of faces may have one or more faces.

Faces Grouping Max. Gap

Note that there are still gaps in the outer boundary. In general, the Automatic Boundaries can be open or closed. Reminder - Automatic Boundaries do not determine the working area but the exact edges of the Part faces.

Contours Creation Max. Gap

Popup Menu Options

The following popup menu options are available when in "Automatic Boundary" mode:

See Surface Selection Options: Popup Menu for a description of these options. The following options are only displayed in "Automatic Boundary" mode; Ignore Contour, Use Contour and Convert to Feature. These specific options are described below.

There may be cases where the quality of the selected faces results in the creation of unexpected Automatic Boundaries. The image below shows two such places.

In such cases you can ignore specific Automatic Boundaries. In face selection mode, pick and then right-click the unwanted segment and select Ignore Contour from the popup menu.

The ignored segment is not deleted, it is only displayed as a dashed line. An ignored segment means that it will not be considered for procedure calculation.

To reuse an ignored segment, reselect it and choose Use Contour from the popup menu.

In some cases it may be necessary to create some of the boundaries manually. In these cases, select the option Manual Boundaries from the screen parameters and pick the required boundaries in the correct order.

It is also possible to convert the Automatic Boundaries into a CAD feature. To do this, pick and right-click the Automatic Boundary and select Convert to Feature from the popup menu. The result of this operation is a composite curve that appears in the Features Tree in the CAD environment (see Switch to CAD Environment).

Some functionality may be dependent on the product package. Contact your Reseller if you require a license.