To Trim Geometry from a Body
You can trim off a portion of a body’s geometry and remove the trimmed portion from the model. There are two ways to trim a body:
Trim a body using a trimming object
Trim a body using a plane, surface, or quit as a trimming object.
1. Click 
Split/Trim Body. The Split/Trim Body tab opens.
Split/Trim Body. The Split/Trim Body tab opens.2. Under Operation, click 
Trim.
Trim.3. With the Body to split collector active, select the body to trim.
4. With the Splitting object collector active, select a plane, surface, or quilt to use as the trimming object.
In the image, the bottom portion of the body is kept, and the top portion is removed.
5. To change the side of the trimming object from which the geometry is removed, next to Splitting object, click 
flip side.
flip side.
In the image, the top portion of the body is kept, and the bottom portion is removed.
6. To extend the boundaries of the trimming object, click 
Extend Splitting Object.
Extend Splitting Object.7. When the trimming object is a surface or a quilt, and it contains colors, to copy the colors to the newly-created surfaces where the body is being trimmed, click 
Copy Surface Appearances.
Copy Surface Appearances.8. Click 
OK. The split portion of the original body is removed. A Trim Body feature appears in the Model Tree.
OK. The split portion of the original body is removed. A Trim Body feature appears in the Model Tree.Trim off a disjoint volume of a body
When the geometry of the original body is made of disjoint volumes, you can split out volumes and remove them from the model. In the example, each gear is a volume that belongs to the same body.
1. Click Split/Trim Body. The Split/Trim Body tab opens.
Split/Trim Body. The Split/Trim Body tab opens.2. Under Split by, click 
Volume.
Volume.3. Under Operation, click Trim.
Trim.4. Make sure the Surfaces collector is active.
5. Under Trim, click an option to select volumes to remove, or volumes to keep:
◦ 
Selected, and then select one or more surfaces on the volumes to remove. The volumes that are not selected are kept.
Selected, and then select one or more surfaces on the volumes to remove. The volumes that are not selected are kept.
The volume on the left is selected to be removed.
◦ 
Not Selected, and then select one or more surfaces on the volumes to keep. The volumes that are not selected are removed.
Not Selected, and then select one or more surfaces on the volumes to keep. The volumes that are not selected are removed.
The volume on the left is selected to keep.
6. Click OK. The split out volume of the original body is removed from the model. A Trim Body feature appears in the Model Tree.
OK. The split out volume of the original body is removed from the model. A Trim Body feature appears in the Model Tree.