Tutorial 21: To Create Combination Supports

Create two different types of support structures in Netfabb and test their performance in Local Simulation.

Video length (6:35).

Sample files for use with the tutorials are available from the Downloads page. Expand the downloaded ZIP archive into a convenient directory from which you can import files into Local Simulation as you need them.

In some cases, users may want to simulate both the preferred homogenized type supports, covered in Tutorial 15, and also the actual fine structured support, on the same model. We will use Netfabb to create support structures for this part.

1. Launch Netfabb, and if you see the My Machines dialog open, showing the Generic MPBF machine, right-click the machine image and select Open Machine. Skip to Step 5 below.
2. To select a machine, first click Home tab > My Machines .
3. If it's not already there, add Generic MPBF to your list of machines.
   1. In the My Machines dialog, click the Add Machine button.
   2. In the Select a machine to add dialog, scroll down the Process Parameters list, expand the Autodesk category, and click Generic MPBF.
      
   3. Click the Add to My Machines button at the bottom of the dialog.
   
4. In the My Machines dialog, with the machine selected in the left pane, click Open.

   You should see Generic MPBF selected at the top of the project model tree.

5. Right-click Generic MPBF > Add Part and add the sample file Example_21.stl .
6. In the right pane, note the check box for Distance between Part and Platform.
   

   In the field to the right, set the distance to 0.00 mm and press Enter. The part must be seated directly on the platform for proper creation of support structures.

7. Click Create Supports.
   
8. At the bottom of the window, click Run Support Script, in the Choose support script dialog, select SLM, and click Execute.
   

   The lattice-like supports are created.

   
9. For this exercise, we want only the back supports to be homogenized. Click each of the two curved front supports to select them, then right-click and choose Remove selection. You may need to do this more than once if you see bits of lattice remaining.
   
   
10. Click Apply support; in the Editor Apply Behavior dialog, click Keep Editor.
11. Click Start build simulation; in the dialog that opens, enter a suitable file path and name, such as Example_21, leaving in place the file extension .3mf. Click Save.
12. In the Start build simulation dialog, ensure that Postprocess-repair support volumes for simulation is checked, select the Local Simulation version, if both are available, and click Simulate.

    The exported file takes a minute or so to generate, then opens inside the Local Simulation window.

13. If you want to reduce the size of the build plate, click Build Plate > Size tab > Snap to X and Y.
14. Return to Netfabb to add the lattice type supports. If the Start build simulation dialog is still open, click Cancel to close it.
15. In the file tree, drag and drop the Example_21 part from the Generic MPBF workspace to the Parts workspace.
16. In the Support panel, click Generate Supports .
17. Click Run Support Script at the bottom of the Support window. Choose SLM type supports from the list and click Execute.
18. Now delete the back supports which have already been generated and homogenized. Do this by clicking to select them, then right-click and select Remove selection.
19. A thickness must be added for the curved front lattice supports to mesh. Select both curved supports by holding down the Ctrl key and clicking the left mouse button.
20. In the right pane, click the Edit tab.
    

    Expand the Structure properties menu by pressing the + symbol.

21. In the Thickening up structure-hatches field, type 0.50. This will create support structure walls approximately 2-3 bead widths wide. Click Apply support; in the Editor Apply Behavior dialog, click Keep Editor.
    
    
22. To use in simulation, these supports must be turned into an STL file. Click Manage Supports > Split Support to new Part > Into single Part.
    
23. In the project tree, you should see the new part under the Parts node, with (support) in its name. If the part does not appear, right-click Parts > Show Part Numbers.
24. Right-click the support part and click Export Part > as STL. In the Export Parts dialog, beside the File Name field, click Select and navigate to the same folder where the first Example_21.3mf file was saved. Name the new file Example21_support.stl, click OK.
25. Return to the Local Simulation window. On the Home tab, click Import. Select the Example_21_support.stl file just created. Designate this as a Support Structure with a Volume Fraction of 1.00 when prompted.
    
    

    Now you have a part with two types of supports, and you can proceed to perform a simulation as outlined in previous tutorials.