Working at MECAD Manufacturing, many of our customers are working on router machines cutting parts out of plastic sheets, or sometimes even metal. When it comes to nesting, customers would use external nesting software to nest their parts, or worse nesting all the parts by hand!

Now, this is very counterproductive, because not only do you waste a lot of time to nest parts by hand, but in the case of other nesting software, you first have to nest it with that software, and then transfer the file to Mastercam. This can cause problems with geometry or file type, and the list goes on and on.

What a lot of people don’t know is, Mastercam has a nesting function and it is so easy to use, you can do it with your eyes shut! (Although I would not recommend it)

For example. Let’s say we have the following three parts:

What we want to do is to nest these three parts on sheet sizes of 600x400mm for as many sheets as needed.

The first thing to do is save each of these parts drawings as P1, P2, and P3. Then open a new session of Mastercam and go to the Transform tab and click on Geometry Nesting.

Once you have done that, this window will pop up.

Here you can set the size of your sheets under the Parameters block (Blue in the picture above), as well as the number of sheets you have and the origin of the sheet. For the first example, I’m just going to tell Mastercam to create enough sheets for the necessary quantity.

Under the Common Parameters Block (Red in the picture above), I’ll set the Sheet Margin to 5mm. This will tell Mastercam to space my parts 5mm from the edge of the sheet.

After that, click on the Parts tab (Green in the picture above).

To add parts to the Part List right-click on the blank list (marked in orange above) and click on Add wireframe parts form files… and then select each of the three files.

Next, set the Minimum Qty of P1 (Triangle part) to 50, P2 (Roof shaped part) to 60 and P3 (Parallelogram) to 20. Then, set the Step Angle to 45 degrees. This tells Mastercam how it’s allowed to rotate the part as seen below:

Note that the Step Angle could be different for each part.

Next, at the Mirror option, I’m going to set it to Original or Mirrored as these parts can be mirrored. At the Part-Part Distance I recommend that you enter the diameter of your cutter, maybe a little more, but for this example I’m going to go with 2mm. Lastly, I’m going to check the Optimized pair’s options, this will create close-fit pairs from parts in the nesting session.

Click on the green check and you will get the following window with the following sheets:

On this page, there are a few options. Firstly, if you need to make any changes to the quantity or step angle etc… You can click on the purple undo arrow (marked in purple above) at the bottom left of the screen to Redo those settings. You can also change the setting on each page by first selecting the specific page, and then clicking on the Customize button as shown below in Red:

If you click on the green check again, it would create the geometry that has been nested and ready to use for your toolpath operations.

As per the last example, let’s say you want to nest the same quantity of parts, but in this case you only have 2 sheets instead of 3 sheets, and the most important part is P2 (Roof shaped part), then P1 (Triangle part) and lastly P3 (Parallelogram). This is where we could make use of the Priority option on the Parts tab:

Now by default, if the priority of the parts is left to 1, Mastercam would give priority to the big parts and fit in all the small parts. I’m going to set the number of sheets to 2 and the priority of P2 to 1 (the highest), P1 to 2 and P3 to 3. Then, click on the green check, you will get the following warning:

Here Mastercam is indicating that out of the minimum of 20 parts set to P3, only 13 were nested due to the prioritry value, giving the following result:

I would encourage you to try Geometry Nest in your shop to see how you could save time, money and frustration with the nesting of parts. For more information on the nesting of part and Mastercam please contact us at MECAD Manufacturing (