Globally Create All Prismatic Machinable Features

This task shows you how to prepare a design part for manufacturing by automatically creating all recognizable prismatic machinable features from the Geometry and Technological Results. There are two methods to create Prismatic Machinable Features:
1) Create Prismatic Machinable Features from Geometry
2) Create Prismatic Machinable Features from Technological Results
The machinable features created with one method, must be updated with that method only, if they need to be updated.
The SampleMPA.CATPart document should be open.

Create Prismatic Machinable Features from Geometry

1. Select the Global Feature Recognition icon . The Global Feature Recognition dialog box appears.
2. Set Selection Type to Body then select the part in the 3D view. The feature recognition takes the associated Body object into account.
4. Select all the FeatureFrame checkboxes so that the part is analyzed for all machinable feature types.

 
  • To create axial machining features only, just select the Hole check box.
  • To create prismatic machining areas only, select all the checkboxes except the Hole check box.
  • To create all holes included in a tab hole, select the Enable creation of tab hole components check box.
    A tab (or tabulated) hole is more complex than a Part Design hole in that its hole chain (that is, all faces) do not match a Part Design feature.
    If the check box is not selected, the holes belonging to the tab holes are not created (default behavior).
  • If the Hole check box is selected, the Only for existing Tech. Results and Only for non existing Tech. Result checkboxes becomes available for selection. If Only for existing Tech. Result check box is selected, machinable axial features are created only for holes of the selected body with Technological Results. For more information, see Support of Technological Results. If Only for non existing Tech. Result check box is selected, holes without associated technological results are recognized.
5. Select the Advanced tab to specify the parameters for specific processing.
See Advanced Parameters
6. Select the Axial Filter tab to create machinable axial features based on the selected filter criteria's.
See Create an Axial Filter
7. Select the Pattern tab to create a machining pattern on machinable features.
See Create a Machining Pattern on Machinable Features
8. Click OK to start the feature recognition process. This process can be interrupted by means of the Cancel button on the progress bar that is displayed. See Interrupt Behavior for more information.

All recognized machinable features are added to the Manufacturing View.
  Note that Selection Type can be set to Face. In this case, all recognized features that open onto selected faces will created.

However, suppose a pocket has a child pocket and the top face of upper pocket is selected.

The child pocket is not created as it does not open directly onto the selected face.

Create Prismatic Machinable Features from Technological Results

The Create Axial Features  from Tech. Result feature is supported for both Global feature recognition by Body and Face. It is not supported for machinable axial feature creation by Local feature  recognition.

1. Set Selection Type to Body or Face then select the part containing all holes in the 3D view. The feature recognition takes the associated Body object into account.
2. Select Create Axial Features from tech. Results check box to create machinable features from the technological results. See Support of Technological Results
The Global Feature Recognition dialog box turns into:

The following functionalities in the Global Feature Recognition dialog box become disabled:

  • The entire FeatureFrame is disabled as the recognition type is applicable for holes only.
  • Tab Holes and Automatic Merge of Co-Axial Holes checkboxes are disabled as hole creation is governed by the technological results.
  • Hole Filtering and Consistency Check between recognized holes and Tech. Results checkboxes are disabled.
  • The entire Advanced tab is disabled as creation of feature and parameter are governed by the technological results.
3. Select the Axial Filter tab to create machinable axial features based on the selected filter criteria's.
See Create an Axial Filter
4. Select the Pattern tab to create a machining pattern on machinable features.
See Create a Machining Pattern on Machinable Features
5. Click OK to start the feature recognition process. This process can be interrupted by means of the Cancel button on the progress bar that is displayed. See Interrupt Behavior for more information.

All recognized machinable features are added to the Manufacturing View.
   

Graphic and Text Feedback about Machinable Features

When you select or move the mouse over a Machinable Axial Feature in the Manufacturing View, feedback in 3D Viewer shows:

  • Highlight of flank RSURs referenced by the Machinable Axial Feature.
  • The entry point and entry vector of the feature.

Machining direction of a recognized "through feature" can be reversed by right clicking that feature in Manufacturing View and selecting the Reverse Machining Direction contextual command.

This command is not available for the blind features, as they can be machined in only one direction. Also this command cannot be accessed if the feature is machined.

The identifier of the Machinable Axial Feature is shown as follows:
Machinable Axial Feature.1 (Simple Hole Diameter=12mm Depth=20mm)
representing in a summary the parameters of the feature.

If you rename the feature:MyFeature.1 (Simple Hole Diameter=12mm Depth=20mm)

Both the graphical representation and the feature in the Manufacturing View are associative and always up-to-date, positioned and filled according to design changes. When geometry can no longer be retrieved from a feature (referenced RSURs are no longer in Design Part, for example) no user representation is displayed.
   

Advanced Parameters

The Advanced tab of the Global Feature Recognition dialog box contains a number of parameters for specific processing.

 

Machining Direction

You can specify a machining direction by selecting a face, a line, or an edge. The created features have a machining axis parallel to the selected direction.

By specifying a machining direction, you can choose to create features that open in that direction only. For example, this may correspond to the machining direction of a particular machine setup.

If no machining direction is selected, the Create features only in this direction check box cannot be selected.

Hole / Pocket or Cutout

Depending on the value assigned for the maximum hole diameter, you can choose to create:

  • either holes
  • or circular pockets or cutouts.

Using this capability:

  • large diameter holes can be created as pockets
  • small diameter intersecting holes can be created as Holes instead of a single complex pocket.

Make sure you have selected the appropriate Feature type in the Basic tab (for example, if you want to recognize a hole as a pocket, select the Hole and Complex Pocket checkboxes or just the Complex Pocket check box).

The behavior can be illustrated by means of the following example.

Consider a selected face with 4 holes with 10mm diameter and 4 holes with 20mm diameter.

Case A
Basic tab: Complex Pocket to be recognized
Advanced tab: check box selected and maximum diameter for hole set to 15mm.

Result: Four holes of 20mm diameter are recognized as Complex Pockets; 4 holes of 15mm diameter are not recognized.

Case B
Basic  tab: Hole to be recognized
Advanced tab: check box selected and maximum diameter for hole set to 15mm.

Result: Four holes are recognized as Holes of diameter 20mm; 4 holes are recognized as Holes of diameter 10mm

Case C
Basic  tab: Complex Pocket to be recognized
Advanced tab: check box not selected, so no maximum diameter is set for hole.

Result: All the holes are recognized as Complex Pockets.

Basic  tab: Hole to be recognized
Advanced tab: check box not selected, so no maximum diameter is set for hole.

Result: All the holes are recognized as Holes.

Ignore Tapered Hole Component

You can choose to ignore the fact that the hole type is tapered during feature recognition. In this way, you can force chamfered holes to be recognized as simple holes.

Chamfered hole:

Recognized hole:
 

User Parameters

You can create pattern based on your own defined criteria using user parameters. You can define your own parameters as part of the Technological results associated to the holes and create patterns based on those in one shot.

Select Include User Parameters in Axial Feature check box to include user parameters in Machinable Axial Feature (MAF). If you select this option then the User Parameters (string and Integer type) present for recognized hole are included in the Axial Feature. It is important to select this option if you wants to enable the pattern creation based on user parameters for the recognized holes.

The User Parameters are available in GFR Pattern tab and in the Pattern Creation dialog box of Pattern Creation command. Refer to Pattern Creation during GFR and Automatic Pattern Creation.

This check box is enabled for selection only if Hole type is selected in the Basic tab.
This feature is available in both Global Feature Recognition and Local Feature Recognition.

Inclusion of User parameters in MAF is possible only during MAF creation, which happens during GFR and LFR.

Global feature recognition read these User parameter values from the TR associated with the Holes so it is compulsory to create TR for all the holes for which you wants to create MAFs and further create Patterns. During both the recognitions, command would read user parameters from TR associated with the holes and create parameters in MAF for all the user parameters. You can see all the included parameters and their value when you checks the definition of the MAF in Manufacturing View. Refer to Display of User Defined Parameters.

The user parameter included in the MAF can be used in Formula and Checks when defining a machining process.

Display of User Defined Parameters

You can see all the included parameters and their value when you checks the definition of the MAF in Manufacturing View. Click More Parameters in the Machinable Axial Feature dialog box.

 

A More Parameters dialog box comes. This dialog shows all the additional parameters. User parameters can also be found in this dialog box. If there is no additional parameter found then More Parameters button remains disabled.

Selection of Bodies

One or more Bodies can be selected.

For feature recognition, the In-Work object must be either a Body or the last component of a Body. For example, in the figures below:

  • if you want to use Body.2 for feature recognition, the In-Work object must be either Body.2 or Hole.2.
  • Body.2 and Hole.1 are valid In-Work objects.

The identifier of the In-Work object is underlined in the tree.
   

Interrupt Behavior

Three types of message appear on progress bar depending on the step in which the recognition process is running:

  • Preprocessing: in this step pre-processing is done for recognizing features.
  • Recognizing Features: In this step actual feature recognition happens.
  • Creating Features: In this step recognized features are created in the manufacturing view, analysis parameters are computed, and patterns are created for recognized holes if pattern creation options are selected.

The behavior when you click the Cancel button to interrupt the process depends on the step in progress:

Pre-processing:
If you cancel the process during pre-processing before the actual feature recognition, there will not be any recognized features.
In this case no feature is created and the progress bar is no longer displayed.

Recognizing Features:
If one or more features are recognized at the time of interruption, a message box appears asking if you want to create these recognized features (Yes/No):

  • Yes: The features recognized up until that point would be created. During this creation, the progress bar is displayed.
    After creation, the progress bar disappear and the Global Recognition summary dialog box will is displayed. It shows the actual number of features created.
  • No: No feature and pattern is created and the progress bar disappears.
    Also, the Global Recognition summary dialog box is not displayed.

Creating Features:
A message indicates that the Creation step was interrupted.
Then the Global Recognition summary dialog box is displayed, showing the actual number of features created up until that point.

Pattern Creation behavior:
Patterns are not created if the process is interrupted (at any step), even if the pattern creation options are selected.
   

Support of Technological Results

In the Part Design workbench, the Create Technological Results contextual command on a part body creates a Technological Results node containing technological information in the PPR tree.

This technological information (thread, minimum, and maximum tolerances) can be retrieved when creating axial features and machining patterns.

When Technological Results exist on the body selected for feature recognition, technological information (thread, minimum, and maximum tolerances) are retrieved in both Local and Global Feature recognition. Created machinable axial features then include the corresponding technological information:

  • Thread semantic value (M8, for example)
  • Minimum and maximum tolerance values.

Information can be retrieved only when Multi-Model Link (MML) documents are loaded.  This allows creating machining features using propagated Technological Results attached to multi-model geometry without needing to load the original documents.

This capability also allows creating axial machining features on propagated Technological Results attached to transformed (translated, rotated, mirrored, patterned, and so on) Part Design Hole and Thread features.

If no Technological Results exist, technological information (thread, tolerances) is retrieved from the design hole.

Automatic pattern creation groups machinable axial features using technological criteria (thread, tolerance). Technological information set on the machining axial feature is used to create the pattern.

Technological Results capability does not take into account semantic tolerances (H7, for example). Any semantic tolerances are retrieved from design holes even if Technological Results have been generated.
If no Technological Results have been created on the body, technological information is retrieved from design holes.