How to Create a Multiaxis Swarf Feature

Introduction

This tutorial explains how to create a Multiaxis Swarf feature. The goal of swarf milling is to create the desired cut using the entire flute length of the tool. This is great for machining fluid parts such as blisks and impellers.

 

Example File

 

The BobCAD part file for this tutorial is available for download at: http://www.bobcad.com/helpfiles. If you are connected to the Internet, you can click the link provided to download and save the Swarf Example 1.bbcd part file. In the example file provided, the Milling Stock and Machine Setup are already defined for the part. The part is simulated using the BC Table Table machine.

 

In this example, you learn how to select geometry and how to set the chain direction of each curve to create the proper results. This example uses the Best Fit strategy and what is explained here can be applied to the other Swarfing strategies. Adding leads, creating multiple steps, adding a gouge check, and an important note on machine movement are also explained.

 

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Part 1) Create the Feature and Define the Tool

Step 1.    In the Data-CAM Tree Manager, click the CAMTabIconBBCD.png CAM Tree tab.

 

Step 2.    Below MillingStockIconWhite.png Milling Stock, right-click MachineSetupIcon.png Machine Setup and click Mill Multiaxis. (You may need to click ExpanderPlusIcon16x16.png to expand MillingStockIconWhite.png Milling Stock.)

 

Step 3.    In the Multiaxis Wizard, select Swarf Machining, and click Next>>. The Work Offset # is set to the value defined in the Machine Setup dialog box. Click Next>>

 

Step 4.    In the Tool Data group, clear the CheckBoxCleared.png System Tool check box and set the Diameter to 0.75, set the Flute Length to 2.00, and change the Corner Radius to 0.00

 

Step 5.    To assign a tool holder, click Assign Tool Holder. In the Milling Tool Holder Library, in the CAT 40 Holder list, click 0.75 inch I.D. Arbor CAT 40, and click OK.

Part 2) Select Geometry

Step 1.    Click Next>> to go to the Parameters dialog box, and in the Swarfing group, set the Strategy to Best Fit. This option allows the system to find the best fit of the tool between the upper and lower rail.

 

Step 2.    In the Geometry Selection group, next to Upper Curve, click EllipsisButtonIcon16x16.png. In the Workspace select the upper curve as shown next. (Be sure to select the surface edge and not the top surface.) Once the proper selection is made, to accept the selection, click OKCheckmarkIconWhite.png (OK).

 

SwarfTutImg3.png

 

 

Step 3.    Next to Lower Curve, click EllipsisButtonIcon16x16.png. In the Workspace, select the lower curve as shown next. To accept the selection, click OKCheckmarkIconWhite.png (OK).

 

SwarfTutImg4.png

 

 

Step 4.    Next to Swarf Surfaces, click EllipsisButtonIcon16x16.png. In the Workspace, select the swarf surface as shown next. To accept the selection click OKCheckmarkIconWhite.png (OK).

 

SwarfTutImg5.png

 

 

Step 5.    The geometry selection for this example is now complete. To view the feature as it is currently defined, using all other parameters at their default values, at the bottom of the dialog box, click Compute. The result is shown next.

 

SwarfTutImg6.png

 

 

Step 6.    Notice that the toolpath computed on the wrong side of the part. To resolve this issue, you must edit the feature. When you computed the toolpath, which closed the wizard, the Multiaxis feature was added to the CAM Tree. To edit the feature, in the CAM Tree, at the bottom of the Feature Multiaxis group, right-click MultiAxisFeatureEditIcon.png Multiaxis, and click Edit.

 

Step 7.    On the left side of the Multiaxis Wizard dialog box, click Parameters. In the Machining group, next to Side, select Right. At the bottom of the dialog box, click Compute.

 

SwarfTutImg7.png

 

 


TIP:   When defining the Machining Side, the direction is determined using the start point of the selected entities. To view the Start Point of each curve, in the CAM Tree, right-click the appropriate GeometryIcon.png Geometry item (First/Upper Edge Curve) and click Modify Start Point. In the Workspace, the start point becomes visible. To change the start point, click near the end of the entity, and then click OKCheckmarkIconWhite.png OK. Keep in mind that each curve must share the same direction to create the proper results. In addition to the previous method, to reverse the direction, you can right-click the GeometryIcon.png Geometry item, and click Reverse Direction.

 

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Part 3) Adding Leads

Notice that in the previous step, that the toolpath is plunging directly into the edge of the part geometry. This is not the desired result for this example. (To simulate the feature and review the result, in the Modules menu, click Mill Simulation.) Next, you add a lead-in and a lead-out to cause the tool to plunge outside of the part, so that the side of the tool is used to begin the cut.

 

Step 1.    In the CAMTabIconBBCD.png CAM Tree, right-click MultiAxisFeatureEditIcon.png Multiaxis, and click Edit. On the left side of the dialog box, click Parameters, and at the top of the dialog box, click the Link tab.

 

Step 2.    In the Entry/Exit group, next to First Entry, (on the right side) select Use Lead-In. Next to Use Lead-In, click EllipsisButtonIcon16x16.png to open the Leads dialog box. Notice at the top of the dialog box, that the CheckBoxSelected.png Use Default Lead-In check box is selected. To close the dialog box, click OK.

 

Step 3.    In the Entry/Exit group, next to Last Exit, (on the right side) select Use Lead-Out.

 

Step 4.    At the bottom of the dialog box, click Default Lead-In/Out. The Default Lead-In/Out dialog box is displayed. In the Lead-In group, next to Type, select Tangential Line. At the top of the dialog box, next to Copy, click RightArrowNextButton.png. This copies the Lead-In settings to the Lead-Out group. To finish and close the dialog box, click OK.

 

Step 5.    In the Multiaxis Wizard dialog box, click Compute. The result is shown next.

 

SwarfTutImg8.png

 

 

Step 6.    To view the result, in the Modules menu, click MillSimulationIconBBCD.png Mill Simulation. To learn more, view the Getting Started with Simulation help topic.

 

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Step 7.    To close simulation, in the Modules menu, click ExitSimulationIcon.png Exit Simulation.

Part 4) Create Multi Cuts

Now instead of cutting the part with a single slice, multiple slices are created using Multi Cuts.

 

Step 1.    To edit the feature, in the CAMTabIconBBCD.png CAM Tree, right-click MultiAxisFeatureEditIcon.png Multiaxis, and click Edit.

 

Step 2.    Click Parameters, and click the Multi Cuts tab. In the Pattern Slices group, in the Depth Steps box, type 4, and click Compute.

 

SwarfTutImg9.png

 

 

Step 3.    Notice that the retract moves are again within the bounds of the part. To change this result, edit the feature, and click the Links tab.

 

Step 4.    In the Links Between Slice group, next to Large Moves, select Use Lead-In/Out (on the right side). Once selected, click EllipsisButtonIcon16x16.png to open the Lead-In/Out dialog box. Notice that the CheckBoxSelected.png Use Default Lead-In/Out check box is selected. To close the dialog box, click OK.

 

Step 5.    In the Multiaxis dialog box, click Compute.

 

SwarfTutImg10.png

Part 5) Adding a Gouge Check

There may be times when you want to use Swarf machining even though the machining surfaces are not truly flat. This could result in gouging the surface if the feature is defined too close to the target surface. In such a scenario, you can use a Swarf feature to get as close as possible to the target surface before applying a different strategy to finish the part. The Gouge Check can be used to push the tool out of swarf, or away from the target surface. This means that the tool is moved away from the surface by drawing a line between the contact points of the upper and lower rail; the tool is moved away at a right angle to this line.

 

Step 1.    Edit the Multiaxis feature, click Parameters, and click the Gouge Check tab.

 

Step 2.    In the Degouging group, select the CheckBoxSelected.png Gouge Allowance check box, and type the desired allowance value in the Gouge Allowance box.

 

Step 3.    The CheckBoxSelected.png Check Against Swarf Surfaces check box is selected by default (you must have at least one surface to check). This creates a gouge check for the selected Swarf surface.

 

Step 4.    If there are additional surface that you want to gouge check, select the CheckBoxSelected.png Additional Check Surfaces check box. Click EllipsisButtonIcon16x16.png to enable selection mode, and select the geometry that you want to gouge check (and then click OKCheckmarkIconWhite.png OK). This can be the part geometry or any other geometry in the Workspace.

 

Step 5.    To update the feature, click Compute.

Part 6) Minimizing Table Rotations

When creating Swarf features, there may be fast machine movements that need to be minimized. The following option is provided to help reduce these movements.

 

Step 1.    Edit the Multiaxis feature, click Parameters, and click the Tool Axis Control tab.

 

Step 2.    Select the CheckBoxSelected.png Minimize Rotation Axis Changes check box.

 

Step 3.    To update the change, click Compute.

 

Step 4.    To view the result, on the Other toolbar, click the SimulationIcon.png Mill Simulation icon.

 

 

This concludes the tutorial. To learn more about any Swarf feature parameters not explained in this tutorial, view the Swarf Machining help topic.