It’s doubtful that you’ll spend your life creating solitary parts—more than likely you’ll need to combine these parts in an assembly. This takes us to the Autodesk Inventor assembly file (which we now know is the IAM file). The assembly file holds the information necessary to put the parts together.

There are three types of assembly design: bottom-up, top-down, and middleout. When you insert existing parts and subassemblies in an empty assembly file you’re designing from the bottom up. Creating all your components within the assembly space is top-down design. Middle-out assembly design is a combination of the two (and the route you will probably take). There is no right or wrong way to do it; you determine the best method for yourself.

Bottom-Up Assembly (A)
If possible, insert your components in the order you want the manufacturer to assemble them. The first component should be a fundamental part of the assembly on which the rest of the assembly can be built. The first component you insert becomes the base component, and it is grounded or fixed.

Top-Down Assembly
If you need to create a component while in the assembly mode, simply select the Create Component option from the Assembly panel bar. You’ll be asked to select the face or plane you want to work from (just like sketching), and the existing assembly becomes translucent.Don’t be fooled; you are still creating a part file (IPT), you’re just doing it from inside the assembly file.

Assembly Constraints (B)
Once you have more than one component in your assembly, you’ll want to ensure that they fit together correctly by placing a variety of assembly constraints. For example, a screw fits inside its corresponding hole. If you need to move the hole, you’d like that screw to follow. There are many different types of assembly constraints: Mate, Tangent, and Insert, to name a few. As you add constraints to the components, you’ll find that you’re reducing their freedom to move.

You can also simulate mechanical motion with the Drive Constraint tool.This allows you to view such motions as a gear being rotated by a pulley, a handle turning, and a piston sliding back and forth. These motion constraints can help you view the overall function of the assembly. Autodesk Inventor can even do interference checking (so you won’t get unhappy calls from the shop floor!).

Adaptive Assembly (C)
As I mentioned earlier, one of the things that differentiates Autodesk Inventor from other 3D modelers is its adaptive technology. Adaptivity allows you to create relationships between parts in an assembly. Once you make a part adaptive, moving or changing adjoining parts forces that part to adapt. This is just a very quick overview of the Autodesk Inventor assembly modeling functions. There are so many amazing capabilities in the assembly mode that it is difficult to stick with a few of the basics. I especially wish I had time to dive into one of the newest Autodesk Inventor features—weldments. In the weldment assembly environment you can do weld bead specification, weld edge preparation, and postweld machining (ahhh—another overview, another time!).

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