Nesting Holes and Dadoes

Introduction

This tutorial will illustrate how to nest parts with holes and dadoes. You will also learn how to utilize the Nesting Layer Manager to assign layers that don't fall into the recommended naming convention, but that need to be assigned into the holes, dadoes, CAD, or ignored groups to be handled as such.

Part 1) Opening the File and Creating a Nesting Job

The first step of any nesting program is to have the parts in mind that we want to nest and create a Nesting Job. In this case we will be opening a file first and then creating a job inside of that file.

1      Open the Hole_Dado_Tutorial.bbcd file from the C:\BobCAD-CAM Data\BobCAD-CAM V**\Examples folder. Note that when creating a nest, the original orientation of the parts in the CAD window is not important. The parts in this file have been moved off to left because we will be setting up our sheet in the X+,Y+ quadrant. This will make things a little easier to see once the nest has been completed.

2      In the CAM Tree tab of the Data-CAM Tree Manager, right-click on CAM Defaults and select New Job to launch the Nesting Wizard.

3      Select Nesting as our Job Type and then click the Nesting Wizard button.

Part 2) Select Geometry

When it comes to picking geometry you can either select geometry that is already open in your CAD window, load geometry from existing files that have not yet been open, or a combination of both. In this case, we will use a combination.

1      Click the Select Geometry button. The Nesting Wizard hides, and selection mode is activated. 

2      Select the icon at the top of your screen or press Ctrl+A on your keyboard to select all of the geometry in your CAD window at the same time. 

IMPORTANT:     Simultaneous selection of all geometry at once is not recommended unless you are absolutely sure the geometry is clean. If you are not sure the geometry is clean, use a chain selection method to pick one chain at a time. Find out more about chain selection here.

3      Once all of the parts are highlighted, press the spacebar on your keyboard, or right click in the graphics area and click OK, to confirm the part selection.

4      The Nesting Wizard returns, and the four separate parts are listed in the Part List area.

5      Notice that there are three colors present in the previews. These represent the various operational assignments of the geometry. They are as follows:

A     Profile

B      Hole

C      Dado

Part 3) Load Files

Now that we have selected the parts from the CAD window, we will import the other files needed for the nesting job.

1      Click the Load Files button and navigate to the C:\BobCAD-CAM Data\BobCAD-CAM V**\Example folder.

2      Click on 8inch_Dadoes_Holes.bbcd to highlight the file.

3      Hold Ctrl on your keyboard and click on 8inch_Dadoes_Holes2.bbcd to highlight that file as well.

4      Click Open to load the two files and launch the Nesting Layer Manager.

Part 4) Organizing the First File

To have the system automatically assign the proper operations to hole and dado geometry, each type of geometry needs to be separated to a layer of the same name. When importing files whose layers do not align with that naming convention, using the Nesting Layer Manager to assign each layer to the proper operational group becomes necessary. Note how the groups are arranged in the example below.

1      With both files already loaded, you will be able to see both files listed in the File Name group. By default the first file is highlighted and all of its layers are visible in the Profile Layers group. Any layer that stays in the Profile Layers group will be handled as a profile. Take a moment to click on each layer name to see the associated preview to the right in order to decide to which group each layer should be assigned.

NOTE:      Notice the preview for the dimension layer is blank. Dimensions are not valid nesting geometry and, as such, will not be shown in the preview.

2      Judging by the previews, it looks like the only thing that should be under the Profile Layers, is the CAD layer, which contains the outer profile of the part. We now need to assign the other layers to the proper groups. Rather than do this manually, click the Auto Assign Layers button below the File Name group.

3      Notice that the layers are not all under the Profile Layers group any longer. Notice in the Log below the following information has been generated:
******************************************************
Layers with Open Chains to Dado: On
Hole Layer Filter: On
MinDiameter: 0.0000
MaxDiameter: 4.0000
8inch_Dadoes_Holes.bbcd
.5 Dia -> Drill Hole Layers
Dadoes -> Dado Layers
1.5 Dia -> Drill Hole Layers
******************************************************

This tells us which layers have been moved, and to which groups the have been moved to. The moves will also be evident in the groups themselves.

4      Notice in the Profile Layers group we have two layers. Since we will not be cutting the dimensions, we will move that layer to the Ignore Layers field. Drag the Dimensions layer to the Ignore Layers group.

5      We have two layers in the Holes Layers group. Now that we are looking at each a little closer, 1.5 inches is too large of a hole to be handled as a drilling operation. We will need to move the 1.5 Dia layer to the Profile Layers group so we can handle that geometry with a profile cut instead.  Drag the 1.5 Dia layer from the Holes Layers group and into the Profile Layers group.

Part 5) Organizing the Second File

1      Click on the 8inch_Dadoes_Holes2.bbcd in the File Name group and take a moment to click on each layer name to see the associated preview to the right in order to decide to which group each layer should be assigned.

2      In this case you can see that the content in the layers, along with the layer names themselves are almost identical to the first part, save for a couple of small variations. In this file as well, we have a 1.5 Dia layer that we will want to have handled as a profile. We will prepare for that prior to using Auto Assign Layers with the Filters.

3      At the bottom left of the Nesting Layer Manager, notice we have a Filters group with two check boxes selected by default. In this instance, we will utilize the Holes Layer Filter option. Since the holes we want to keep in the Profile Layers group are 1.5 diameter, enter 1.0000 in the Max Diameter field of the Holes Layer Filter option.

4      Click the Auto Assign Layers button below the File Name group.

5      Notice that our 1.5 Dia layer has remained in the Profile Layers group thanks to our filter.

6      Drag the Dimensions layer into the Ignore Layers group.

7      Click OK.

Part 6) Setting Part Parameters

Now that the parts are all loaded, and the layers have been organized, we will set some basic part parameters.

1      In the Part Geometry page, notice that we now have Part 5 and Part 6 loaded in the part list. Take a moment to click on each of these to see the associated preview and their color assignment.

2      Click Next>> to continue to the Part Parameters page.

3      Fill out the part quantities to match the following values.

Part 7) Setting the Cutting Strategy

With the Part Parameters set, we will need to adjusting settings for the operations themselves.

1      Click on the Default Profile in the tree to the left of the wizard and set the Total Depth value to 1.0000.

2      Click on the Rough in the tree under Default Profile. Change the Diameter value of the default tool from 0.5000 to 0.3750.

3      Click on Leads under the Default Profile to jump to the Leads page.

4      Select the Circular option for the Lead-in.

5      Set the Length value in the Line group to 0.1875 and the Radius value in the Arc group to 0.1875 as well.

6      Click on the Default Hole in the tree to the left of the wizard and set the Total Depth value to 1.0000.

7      Click on the Rough in the tree to the left of the wizard under Default Dado.

8      Change the value for Diameter from 0.5000 to 0.2500 to set our dado tool to the correct size.

9      Click on Leads under the Default Dado to jump to the Leads page.

10  Select the Parallel option and then click Compute at the bottom right of the wizard.

Part 8) Checking the Result

Now that the nest has been generated, we will want to make sure all the parts quantities fit on the sheet.

1      In the CAM Tree, right-click on Sheets and select Show Summary. Here we can see we have three leftover parts. We will attempt to adjust the result to fit the others on the sheet as well.

2      Click OK at the bottom of the Nesting Summary to close it.

Part 9) Adjusting the Result

Now that the nest has been generated and we can see there are a few parts that have not been fit, we will try to adjust a setting to get a better result.  

1      In the CAM Tree, right-click on Nesting Job and select edit to launch the Nesting Wizard again.

2      Click Nesting Parameters in the tree to jump to the Nesting Parameters page.

3      Click the Other Options button to launch the Other Options dialog box.

4      Select the check box for Best Nesting Direction and click OK to finalize changes and close the Other Options dialog box.

5      Click Compute at the bottom right of the Nesting Wizard.

Part 10) Checking the Result

Now that the nest has been regenerated, we will want to check to see if the change we made to the Nesting Parameters has helped eliminate leftover parts.

1      In the CAM Tree, right-click on Sheets and select Show Summary. Here we can see we have no leftover parts.

2      Click OK at the bottom of the Nesting Summary to close it.

Part 11) Simulating

Now that the nest has been generated and all the parts fit on the sheet, we will check the simulation to visualize the machining order prior to posting the code.

1      Right-click on the Nesting Job and select Simulation to enter into the simulator to check the final result.  Learn more about the simulation here.

Part 12) Posting the Program

Once the nested result has been finalized it will be time to produce the code to send to the machine.

1      In the CAM Tree, Click the plus symbol next to Sheets to show its contents.

2      Click the plus symbol next to Sheet-1 to show its contents.

3      Right-click Sheet-1-1 under the main Tutorial sheet type and select Post Sheet.

4      The code is posted in the Layer-UCS-Post Manager.

5      Right-click on the code in the Layer-UCS-Post Manager to select Save As or Edit CNC. With this method, you can either save to a particular file location or to open in Predator Editor respectively.

This concludes this tutorial.