2009

Assembly Design Strategies
Traditionally, designers and engineers create a layout, design the parts, and
then bring everything together in an assembly. With Autodesk Inventor, you
can create an assembly at any point in the design process instead of at the
end. For a clean sheet design, you start with an empty assembly and create
the parts as you develop the design. To revise an assembly, you create the new
parts in-place so they mate with existing parts. This design methodology
supports top-down, bottom-up, and middle-out design strategies.
The optimal order in which you create parts and subassemblies depends upon
your answers to the following questions:
■ Can you modify an existing assembly or do you have to start a new one?
■ Can you break the larger assembly down into subassemblies?
■ Can you use existing parts or iFeatures?
■ Which constraints drive the functionality of the design?
Changes you make to external components are automatically reflected in your
assembly models, and the drawings you use to document them.
Bottom-Up Assembly Design
When you design from the bottom up, you place existing parts and
subassemblies into an assembly file, and position components with assembly
constraints, such as mate and flush. If possible, place components in the order
in which they would be assembled in manufacturing.
Unless component parts are built from adaptive features in their part files,
they might not fit the requirements of an assembly design. You can place such
a part in an assembly, and then make the part adaptive in the assembly
context. The part is resized in the current design when you constrain its
features to other components.
If you want all underconstrained features to adapt when positioned with
assembly constraints, designate a subassembly as adaptive. When a part in
the subassembly is constrained to fixed geometry, its features are resized as
needed.
132 | Chapter 7 Managing Assemblies