Preparing 3D Scans For Vacuum Forming: How to do it in SelfCAD
After 3D scanning, the captured data may require post-processing or it will need to be prepared for vacuum forming. Vacuum forming is where a physical replica of a scanned object is created using a mold. This mold is then placed in the vacuum-forming machine, where a heated sheet of material is placed over it. The vacuum is then applied, causing the heated sheet to conform to the shape of the mold, creating a detailed and accurate physical replica of the scanned object. So before using your design for vacuum forming, there are a few things you need to do with your 3D scans, and that's what we are going to check in the steps below.
Steps to Preparing 3D Scans for Vacuum Forming
To begin, launch SelfCAD and open the workspace:
In this section, we want to prepare the object below for 3D printing and later for vacuum forming:
On the right side panel, turn on the Back Face Coloring:
There, you notice that this is just a shell, a surface without any thickness. If you select this object, you notice that it has 288k faces. Therefore, we need to simplify it. From the Modify category, select Simplify Object:
Set the Intensity to 5:
The faces have been simplified up to 28k from 288k, but the look is still the same:
The first step is to flatten the base of this model. Activate the Edge Selection and click on the gear icon to open the Edge selection settings, Click on Select Loose:
Then go to the Modify category and select Extrusion. Set the Amount to 5 and tick the check mark to finalize the extrusion:
As you can see above, new faces have been created, which are visible if you look keenly, as highlighted above by the red arrows. Objects still selected, go to the Deform category and select Flatten:
Use the Gizmos to move it down:
The results will be as follows:
Click on the grid to deselect objects. Click to select the entire object and from the Utilities category, select Flip Normals:
The problem has been fixed by the Flip Normals but still, there are other faces visible:
From the selection settings, click on the gear icon to open the Advanced Settings of the Edge selection and click Select Loose Edges, as highlighted below:
Use the Move tool on the toolbar, to move the edges slightly down using the gizmos:
And the problem is fixed. The next step is to add a custom support structure. On the Modify category, select Cut With Plane. Select Left/Right plane:
On the Advanced Settings, set the Copy Profile to true. Tick the check mark to finalize the Cut with Plane:
Click Hide the object to remain with the profile:
Set the rendering mode to Solid + Wireframe on the right side panel. From the Drawing category, select 3D Sketch. Use the Line Sketch to draw the line by snapping to the points shown below:
The next step is to close it. In this case, we will not use Extrusion, but instead we are filling the polygon. From the Tools category, select Fill Polygon. Then tick the check mark to finalize it:
You will have a basic shape, which we need to add thickness. On the Modify category, select Add Thickness. Set the Mirrored Thickness to true. Set the Thickness to 3 and tick the check mark to add thickness:
Unhide the mesh that we had hidden and then set the rendering mode on the right-side panel to Solid. Select the mesh, go to the Modify category, and select Add Thickness to add the thickness. Set the Amount to -3 and tick the check mark to finalize the thickness:
Click Ctrl + U to activate the Union in the Stitch and Scoop to stitch the meshes together:
Creating Holes For the Vacuum Forming
In this section, we are looking at how to create the holes for vacuum forming. We will utilize the cylinder shape. From the 3D Shapes category, select the Cylinder and set the parameters as shown below:
Scale the size down by setting the X and Z to 0.75 and Y to remain at 500:
Select the cylinder and select the Align tool from the Utilities category. Set the Align mode to Position. On the Reference, select Union_1 mesh and Align it to Back Left as shown below:
Next step, we want to create copies of the cylinder. Select the cylinder, and on the Tools category, select the Copy Offset tool. Set the Position X to 25 and the Number of Copies to 17:
Group the copies together by clicking Ctrl + G:
Set X to 0 and set Z to 25. Set the Number of Copies to 18 and click Copy to make more copies of the cylinders in the Z direction:
Click Ctrl + G to group the copies together again:
On the toolbar, from the Stitch and Scoop tool, select Difference. Select the group_3 (the cylinders put together) to subtract it:
Tick the check mark to finalize the difference:
If you set the Color to red, and zoom the object to inspect it, you will be able to see the tiny holes created as shown below:
That is how you can prepare your object for vacuum forming:
By following the steps outlined in this guide, you can ensure that your scans are optimized for the vacuum forming process, resulting in accurate and reliable dental appliances. Paying close attention to the details and following the best methods will make your dental work better and faster, which is good for you and your patients.
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