Thursday, January 27, 2011

Autodesk Inventor Assembly Design Approach

There are basically three approaches to assembly design with Autodesk Inventor: the Top-down approach; the Bottom-up apprach; and the middle-out approach. Perhaps, you might have been using these approaches already without recognizing them. So let's see what they are all about.

Bottom-Up Approach

The bottom-up approach to designing an assembly involves constructing all parts or components that make up the assembly in separate part files and placing them into the assembly using the Place Component tool. When this approach is used, the parts or component making up the assembly are external references and are can still be referenced in other assemblies or subassemblies. This approach is also very suitable in situations where most of the dimensions of the components are known.

Top-Down Approach

The top-down assembly design approach involves creating of components or parts in-place or within the assembly environment. This is done by using the Create Component tool in Inventor. When using the Create Component tool, the new component will be referenced from a plane - which may be the default XY, XZ, or YZ planes, user-defined work plane or the face of an existing part in the assembly. Components created in the assembly environment are adaptive and will update if any parameter of the reference component is changed.

Parts created with the top-down approach are internal to the assembly unless they are externalized. The process of externalization is automatically done by Inventor when the assembly file is saved. Another thing to be noted in the top-down approach in Inventor is that assembly constraints are automatically applied between the new parts and the features (planes) they were referenced from.

Let me also add that the method is very suitable when you need one or more parameter of a part to be referenced to another parameter on a different part making the new component adaptive as said earlier.

Middle-Out Approach

The middle-out assembly approach is also known as the hybrid approach. In this approach one combines the techniques of the bottom-up and top-down assembly design approach. This means that some of the files will be designed in-place (inside the assembly environment) while others will be designed in the part environment and placed into the assembly.