How Subtract AutoCAD Models? | TutoCAD

Subtracting Models in AutoCAD: A Step-by-Step Guide

When working with 3D models in AutoCAD, subtracting one model from another is a crucial operation. This guide will provide you with detailed steps for performing this function effectively using various methods available in AutoCAD 2025.

Using the SUBTRACT Command

1. Selecting the Base Object: Launch AutoCAD and open your drawing that contains the solid objects. Begin by typing SUBTRACT in the command line and press Enter.

2. Choose the Object to Subtract From: Click on the solid or surface that you want to retain as the base object. This will be the object from which another object will be subtracted. Confirm your selection by pressing Enter.

3. Select the Object to Subtract: Now, select the solid or surface that you want to remove from the base object. Once selected, press Enter again to confirm.

4. Review the Result: The operation will create a new 3D model with the second object removed from the first. Inspect the result to ensure it meets your expectations.

Utilizing the SURFTRIM Command

1. Activate SURFTRIM: Type SURFTRIM into the command line and hit Enter to start the process.

2. Select Keeping Objects: Click on the objects that you wish to keep in your model and press Enter.

3. Identify Objects to Subtract: Next, select the objects that you want to subtract from your selection. Again, confirm by pressing Enter.

4. Finalization: A single new 3D solid or surface will be generated based on your selections, allowing for complex designs to be created effectively.

Subtracting Solids via the Menu

1. Access the Menu: Navigate to the Model tab on the ribbon interface.

2. Select Subtract: Look for the Subtract Solids option in the dropdown and click it.

3. Simultaneous Selection: Similar to the previous methods, select both the base solid and the object you want to subtract from it. Follow up with an Enter command to confirm.

4. Completion: The operation completes, and a new solid is created with the subtraction applied.

Using the INTERSECT Command

1. Initiate INTERSECT: Start the command by typing INTERSECT in the command line, followed by Enter.

2. Selection of Solids: Choose the solids, surfaces, or regions you want to intersect, and press Enter.

3. Finish the Operation: A new 3D solid will be formed based on the overlapping volume of the selected objects. Review your work to ensure accuracy.

Deselecting Selections

When managing selections, freeing up an unwanted selection might be necessary.

1. Using the Deselect Icon: Click the deselect icon available in the selection controls.

2. Shortcut Keys: Alternatively, use shortcut keys like ALT + SHIFT + C or CTRL + SHIFT + Z to remove selected items swiftly.

Frequently Asked Questions

1. Can I subtract multiple objects at once in AutoCAD?
Yes, you can select multiple objects to subtract from the base object by ensuring they are all selected during the subtract command.

2. How do I know which command to use for specific tasks in AutoCAD?
Refer to the AutoCAD help documentation or type the command you wish to use in the command line for prompts and guidance on its use.

3. Is there a way to redo a subtraction if I make a mistake?
If you make a mistake during your operations, use the UNDO command immediately after or access your history as needed to revert the changes.