Assembly Layout Sketch
You can design an assembly from the top-down using layout sketches. You can construct one or more sketches showing where each assembly component belongs. Then, you can create and modify the design before you create any parts. In addition, you can use the layout sketch to make changes in the assembly at any time.
The major advantage of designing an assembly using a layout sketch is that if you change the layout sketch, the assembly and its parts are automatically updated. You can make changes quickly, and in just one place.
To use an assembly layout sketch, do the following:
Create a layout sketch in the assembly in which various sketch entities represent parts in the assembly. Indicate a tentative location for each component, capturing the overall design intent.
Reference the geometry in the layout sketch when you create each component. Use the layout sketch to define the component size, shape, and location within the assembly; make sure that each part references the layout sketch.
Creating a Part in an Assembly
Inserting a New Sub-assembly