Material Removal Simulation

This section deals with the material removal simulation capability provided with the Replay Tool Path command.

CATProduct User Representation of Milling Tools

You can attach a CATProduct to a tool or tool assembly by means of the NC Resources > Add User Representation contextual command in the Resource List.

Parts of this CATProduct are the components of the tool:

• tool holder, which is a non-cutting component
• shank, which is a non-cutting component
• cutter, which is a cutting component.

The tool created from the CATProduct can be used in Video simulation. This tool can have multiple cutters, holders, and shanks.

Please note however that user representation may reduce the performance of the material removal simulation.

Preliminary Settings under Tools > Options

To allow Parameter nodes to be displayed in the PPR tree, make the following settings in Tools >  Options:

• Parameters and Measure category: select the Parameter Tree View With value and With formula checkboxes in the Knowledge tab.
• Infrastructure > Part Infrastructure category: select the Parameters  checkbox in the Display tab.

Tool Structure

You can define tool geometry as a CATProduct file. CATParts instantiated in this CATProduct (there may be intermediate products between root product and parts at any level ) are components of this tool. A given component may be instantiated several times in the product, at different locations.

Naming Convention and Content of Parts

Some components are cutting components and are used in simulation and in In-Process Model (IPM) generation. Some other components are non-cutting and are used in collision detection. A non-cutting component may be a shank or a holder. These sub-categories of non-cutting components must be differentiated as well.

To identify the type of a component, the corresponding CATPart must contain a Knowledgeware parameter (added using the Fx button in Part Design).
Parameter name is CuttingType (type string).
Possible values of this parameter are CUTTER, SHANK and HOLDER.
Any CATPart not containing this parameter is ignored in the simulation and in IPM generation.

Note that Photo simulation allows one shank or holder only.

In the following example:

• CUTCutterBig.1, CUTCutterBig.2, and CUTCutterSmall.1 are cutting components (note that one of them is instantiated twice).
• NOCUTShank.1 is a non-cutting component.
• HOLD.1 component is ignored in simulation and in IPM generation.

Material Removal

You can perform material removal with tool assemblies with multiple cutting parts.

For example:

If you perform machining with the tool assembly as shown above, then all three cutting parts should be considered for material removal.

CATProduct User Representation of Lathe Tools

You can attach a CATProduct to a lathe tool by means of the NC Resources > Add User Representation contextual command in the Resource List.

Parts of this CATProduct are the components of the lathe tool:

• insert, which is a cutting component
• insert holder, which is a non-cutting component.

The lathe tool user representation can be used in Video simulation. However, unlike the user representation used for milling tools, only one cutting and one non-cutting component can be used for lathe tools. Also, the insert holder does not participate in material removal (regardless of Rapid or Feed mode) and is used only for collision detection.

The sketch conventions outlined below for cutting and non-cutting components must be respected. Non-cutting parts must be convex (that is, the profiles used do not have any cut-outs).

Please note however that user representation may reduce the performance of the material removal simulation.

Preliminary Settings under Tools > Options

To allow Parameter nodes to be displayed in the PPR tree, make the following settings:

• Parameters and Measure: select the Parameter Tree View check box in the Knowledge tab.
• Part Infrastructure: select the Parameters check box in the Display tab.

To allow you to pick individual points during the material removal simulation, make the following setting:

• Sketcher: set Grid Graduations to 100.

Define the Cutting Component (the insert)

Create a part (New > Part) then select the F(x) Formula command.

In the Formula dialog box, set CuttingType to CUTTER.

In the Sketcher workbench, select the ZX plane (in lathe machining, Z is the spindle axis and X is the radial axis). Create a closed profile, adding successive elements in the anti-clockwise direction.

 Note that:

• the Sketch user representation of tools can include construction elements.
• transformations (such as rotation or translation) must not be applied on this sketch as they will not be taken into account for simulation.

In the Part Design workbench, create a Pad from the sketch (2mm thick, for example). This will represent the lathe insert.

Right-click the Part in the tree and select Properties. Rename the Part Number (Insert001, for example).

Save the CATPart.

Define the Non-Cutting Component (the insert holder)

Define the non-cutting component using the same procedure.

Create a part (New > Part) then select the F(x) Formula command. In the Formula dialog box, set CuttingType to HOLDER.

In the Sketcher workbench, select the ZX plane. Create a rectangle.

In the Part Design workbench, create a Pad from the sketch. This will represent the lathe insert holder.

Right-click the Part in the tree and select Properties. Rename the Part Number (Holder001, for example).

Save the CATPart.

Create the CATProduct User Representation

Create a new CATProduct instantiated with the Insert and Holder CATParts.

You can then use the CATProduct as the Tool in the Video simulation.

CATProduct User Representation of Cleaning Tools

A Cleaning operation is a non-machining operation that uses a CATProduct user representation tool. It is defined by first creating a machining operation (depending upon the strategy required by the cleaning process) so as to generate the tool path for cleaning. Then by assigning a specific user representation tool a cleaning behavior can be simulated. Cleaning simulation can be performed in Video mode only.

The tool assigned to cleaning operations must be a CATProduct user representation and must conform to the following rules. The CuttingType knowledge attribute needs to be defined with a value equal to CLEANING for defining the cleaning component of the tool (which may be a brush, for example). Possible values for the non-cleaning components are SHANK and HOLDER.

In operations where cleaning tools as described above are used, the Video simulation has the behavior as illustrated below:

• The cleaning tool will not remove any material.
• Collisions will be detected (if collisions detection is set ON) between the holder and the other components in the system, as is the normal collision detection behavior.
• In rapid mode, collision detection will be performed between the cleaning element and the rest of the components in the system, including the stock.
• No collision will be reported during the cleaning action, provided it is in feed mode between the work-piece and the cleaning element of the tool.

Note that Cleaning tools are not supported for turning operations or in Photo mode.

CATPart Tools for Photo or Video Mode

Please note that the CATProduct user representation of tools described above is the recommended method.

You can attach a CATPart to a tool or tool assembly by means of the NC Resources > Add User Representation contextual command in the Resource List.

You can add a sketch called CUT to define the cutting part of the tool and, optionally, a sketch called NOCUT to define the non-cutting part of the tool. These profiles will be used in the material removal simulation in Photo or Video mode.
Note that the sketches must be called CUT and NOCUT: no other names are possible.

Please note however that user representation may reduce the performance of the material removal simulation .

Here is a step-by step procedure for defining the CUT and NOCUT profiles.

Define a closed profile representing the cutting part of the tool:

• In the Sketcher workbench, create a sketch in the Oyz plane.
• Click the Axis icon then create an axis from (0,0) along the V-axis. 
  This is useful if you want to use the profile to generate a 3D representation of the cutting part of the tool.
• Create the profile, starting from a position on the V-axis. Create the profile using line segments and circular arcs in an anti-clockwise direction. H coordinates must be positive. Close the profile using a line segment.

Examples of correct profiles:

 

• Using the Properties contextual command, name this profile CUT in the Feature Properties tab of the dialog box that appears.

If needed, define a profile representing the non-cutting part of the tool:

• In the Sketcher workbench, create a sketch in the Oyz plane.
• Click the Axis icon then create an axis from (0,0) along the V-axis. 
  This is useful if you want to use the profile to generate a 3D representation of the non-cutting part of the tool.
• Create the profile, starting from a position on the V-axis. Create the profile using line segments and circular arcs in an anti-clockwise direction. H coordinates must be positive. Close the profile using a line segment.
• Using the Properties contextual command, name this profile NOCUT in the Feature Properties tab of the displayed dialog box.

Stock, Design and Fixtures for Material Removal Simulation

The following can be defined as stock, design or fixtures in the Part Operation editor:

• CATPart bodies
• hybrid bodies
• cloud of points bodies
• Video result stored in a CATProduct.
  Note: This CATProduct contains cgr (CATIA graphic representation) and WPC information.

Video results can be used effectively in a Part Operation that contains more that one program. The Video result of the last operation of a program can be used as the stock for a following program. For that, you must set the Simulation at Part Operation level option and use the Video from Last Saved Result command when using simulation in the following program.

If there is no stock defined, the envelope volume of the design part is used. If there is no design part, the envelope volume of the design part is used.

In Video mode only, if the stock geometry is not correctly closed, a stock representing the envelope volume of the design part is computed.