SolidWorks 2010 Bible

Chapter 12: Building Efficient Assemblies

Grouping subassemblies by relative motion

A more natural way to group subassemblies is by considering relative motion. In the bicycle

example, each wheel is a separate subassembly because it moves as a unit relative to the rest of the

assembly. Figure 12.8 illustrates where relative motion might be on the bicycle.

FIGURE 12.8

Grouping subassemblies by relative motion

Rear suspension swingarm Front suspension linkage

Rear wheel Drive train Front wheel

Grouping subassemblies by relative motion is great for assembly modeling, but it does not usually

reflect product reality very well. Using this method, you often end up with parts in the subassembly

that will have to be disassembled in order to actually put the physical parts together. However, if

your only consideration is ease of modeling, then this is probably the method to use.

Organizing groups of purchased components

If you are modeling a product that is created from a shopping list of purchased components, then

it may make the most sense to organize your subassemblies into groups of parts that are purchased

together. In fact, purchased subassemblies are often modeled as single parts, except when relative

motion is required in the purchased assembly.

For example, in the bicycle assembly, the sprockets on the rear wheel are purchased as a separate

unit, and yet the part that mounts onto the wheel moves relative to the sprockets that are driven by

the chain. This is an example of a purchased part that would be modeled as a subassembly to show

relative motion. The bicycle chain, another purchased subassembly, has not yet been added to this