User Manual

UnDerstanDIng FUnctIonal DesIgn
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Too Busy Getting Drawings to the Shop to Build Virtual Prototypes?
You have deadlines to meet, you’re trying to learn a new design tool (Inventor), and you are being
told to spend more time building models? Deciding when to build a virtual prototype depends
on your business and the complexity of the design. At some point, everyone has probably given
rough sketches to the shop to get a part made, but no one wants to do that on a regular basis. In the
beginning, the work you do with Inventor will probably lean more toward just a 3D model and less
toward a 3D prototype, and that’s okay.
As you continue to work, look for areas where you can improve your models and make them more
intelligent. If you know a design is likely to change, build your model with those changes in mind. The
better the model, the easier it is to verify that a replacement component will fit properly, and doing
a major redesign on a product will go more smoothly if you have a solid base from which to work.
Keep in mind that Inventor has a large and deep toolset, but if you’re like most people who use it
in the real world, you’ll probably not use many of these tools. If you create a lot of steel frames and
weldments, it’s likely that you will not have a big need for the plastic features tools. Take the time
to understand and learn all of the tools available so that you know what Inventor has to offer, but
then focus on the parts you need and use most often, and get the most out of those tools.
Understanding Functional Design
Part of creating a fully functioning 3D virtual prototype is using the functional-design tools.
Functional design is an Autodesk term for a knowledge content tool that moves the user from
creating geometrical descriptions (mere 3D modeling) to capturing knowledge. For instance, if
you had the need to create a spring, what tools would you use? You could use the coil tool and
develop a nice spring-shaped model. However, if the actual goal were to determine what size
spring you needed for a particular set of load inputs, then you’d want to use the Compression
Spring generator. You can use the functional-design tools to analyze the function (load of a
spring) and solve the design problems (what size spring is required) rather than spending time
on modeling a solution needed to create 3D representations.
The V-belt Generator
An example of functional design and its benefit is the use of Inventor’s V-belt Generator. Traditionally,
to design a pulley system, you would lay out the pulleys in positions as required by the design and
then choose a belt that met the design requirements and came as close as possible to fitting the pulley
spacing. The result oftentimes is that no common belt size fits the pulley spacing. The functional-
design approach to this task allows you to specify the belt from a standard catalog of belt sizes at
the same time that you are creating the rest of the system. In this way, you know from the outset
that the design is indeed functional and will work in the real world.
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