How to Hollow Out a 3D Object in AutoCAD?

Creating a Hollow 3D Object in AutoCAD

When working with 3D modeling in AutoCAD, one common task is to create a hollow object. This process can be accomplished using a variety of methods, including extruding, subtracting, and using specific commands. Below are the detailed steps for hollowing out a 3D object in AutoCAD 2025.

Step 1: Begin with a Solid Object

1. Open AutoCAD and initiate a new project or open an existing file containing your 3D model.
2. Ensure you are in the 3D Modeling workspace. If necessary, toggle to this workspace by clicking on the Workspace Switching icon on the status bar.

Step 2: Create the Solid Shape

1. Draw your initial shape. For instance, if you want to hollow out a cylinder, select the Home tab, navigate to the Modeling panel, and then select Cylinder.
2. Define the base center and specify the radius and height of the cylinder by following the on-screen prompts.

Step 3: Use the Shell Command

1. Access the Shell Command: Type SHELL in the command line and press Enter. This command allows users to hollow out solid objects by converting them into shells.
2. Select the Solid: Click on your solid object (e.g., the cylinder) to select it and press Enter.
3. Specify the Thickness: When prompted, input the thickness of the walls you want to retain. This thickness determines how hollow the interior will be.

Step 4: Confirm and Modify as Needed

1. After you specify the thickness, AutoCAD will create a hollow version of your object while retaining the defined wall thickness.
2. If adjustments are necessary, you can use the Properties Palette to modify the dimensions, or you can undo the operation and try again with a different thickness.

Step 5: Visualize the Hollow Object

1. To better view the hollow feature, switch to the visual style either by clicking on the Visual Styles icon in the View tab or by typing VISUALSTYLES in the command line.
2. Choose a style such as Conceptual or Realistic for a better understanding of how the hollow object appears.

Alternative Method: Using the Subtract Command

1. If you want to create a hollow object from two shapes, start with a larger solid shape (such as a cylinder).
2. Next, create a smaller solid shape (such as another cylinder) that is centered inside the first solid. Ensure that this inner shape is slightly shorter or has a smaller radius.
3. Select the larger solid first, then type SUBTRACT in the command line and hit Enter.
4. Select the inner solid and press Enter. This will effectively remove the inner volume, making the outer shape hollow.

FAQ

Q1: Can I hollow out any type of solid shape in AutoCAD?
A1: Yes, the shell command and subtract method can be applied to most solid shapes in AutoCAD, including cones, spheres, and more.

Q2: What happens if I set the thickness to zero while using the shell command?
A2: Setting the thickness to zero will result in the original solid being eliminated, as there will be no walls left to form a hollow shape.

Q3: Can I revert a hollow shape back into a solid?
A3: Once a solid has been modified to become hollow, you cannot directly convert it back. However, you can recreate the solid shape with the desired dimensions.