Advanced Nesting

In this tutorial we will explain the more advanced features of the BobCAD-CAM V25 Nesting module such as creating holes, dadoes, and adding machining operations such as pockets and chamfers.


1.  First go to File and click Open and locate the Examples folder under the BobCAD-CAM V25 directory. This is commonly found in the C:\Program Files\BobCAD-CAM\BobCAD-CAM V25\ folder. Open the file named Nesting_Tutorial2.bbcd



2.  One of the most important things to notice about this file is the use of the CAD layers. Notice in the Layer manager, that this file contains 2 special layers used in Nesting; a layer named Holes, and a layer named Dado.


3.  By blanking each individual layer, it should be noticed that the 4 outer holes (shown in green) in the part have been placed on the Holes layer, and the 2 open shapes (shown in orange) at each outer edge of the part have been placed on the Dado layer. Any open shapes that wish to be added to the Nesting must be located on the Dado layer. If help is needed for creating and naming layers, please refer to the BobCAD-CAM V25 Help System. Note that colors make no difference in the nesting result.

4.  Begin by right clicking on Milling Stock and choosing Nest.


5.  The Nesting Wizard will be displayed. On the first page choose the Pick Geometry button and click and drag a window around the part to be nested. When the part is highlighted, right click in the CAD window and choose OK, or simply press the space bar to complete the selection. After this is completed the Nesting Wizard will return displaying one part in the Part list.


6.  Click the Next button to move to the Parts Parameters page. Change the number of parts to 45.


7.  Click the Next button again to move to the Select Sheets page. Nothing is to be changed here, so click the Next button again to move to the Nesting Parameters page. The areas we are concerned about here are the Machining Order and the Cutting Order. Leave Holes first selected so all of the drilling will occur first, and change the Cutting Order to By Sheet, so all of the holes in the sheet will be drilled prior to moving to another machining operation. Choosing By Sheet minimizes tool changes by using that tool over the entire sheet before moving on to the next machining operation. Also change the Bridge Distance to 1.000.


8.  Click the Next button again to move to the Select Tools page. For this example, change the values to match the following image:



Notice we have modified the depths and diameters for different machining operation. Things such as feeds and speeds, lead types, and depths of cut can be modified further by clicking the Edit Advanced button under each category. Click the Finish button to create the Nesting Feature.


9.  Notice that because of the different layers, we now have 3 default operations; Default Profile, Default Drill, and Default Dado. The machining options can be edited by right clicking on these items. For example, expand the Default Drill item, and right click on Drill Hole and click Edit.


10.  The Drill Hole edit dialog will appear. Click on the Parameters item and choose Peck to have the drill perform a pecking cycle. Note that all drill parameters and tools can be set in this dialog.


11.  Click OK to close the dialog.

12.  Now let’s look at adding different types of machining features to the inner shapes of the nesting part. Start by expanding Part 1 under the Nest Parts item.  Each shape will be listed separately under each part in the Nesting Feature.


13.  Click on Inner Profile 1 and notice that the corresponding geometry highlights in the CAD window.


14.  Next right click on Inner Profile 1 and choose Insert Pocketing.  This will assign that shape to a Pocket Feature, and also remove the geometry from the Default Profile Feature inside of the Nesting Feature.


15.  In order to modify the pocketing parameters right click on the Pocket item and click Edit to begin editing the Pocket Feature parameters.  The Pocket dialog will be displayed.  For this tutorial, we can leave the defaults, so editing the feature is not necessary.

16.   Right click on Inner Profile 3 and add another Pocket Feature to this shape, so that each shape will be cleared out.


17.   Now that we have added our pocketing features, we can now recompute the nesting result.  Do so by right clicking on the Nest Parts item and clicking Compute Toolpath.


18.  Notice that now the nesting result contains pocketing toolpath for each shape.



It important to note that each type of shape has different available machining features that can be added. Right clicking on a Dado item under a part allows for adding a custom profile feature, an engrave feature, or a chamfer feature. All of the available hole drilling operations are available when selecting a Hole shape. Inner Profile items can be assigned Profile Features, Pocketing Features, HS Pocketing Features, Engraving Features, and Chamfer Features.


19.  Right click on Sheet 1 and click Start Simulation to see the simulation of the nested result.