Part I: Introducing Assembly Basics
In This Part
Chapter 1
Understanding Assemblies
Chapter 2
Navigating the Assembly Interface
Chapter 3
Visualizing Assemblies
Chapter 1: Understanding Assemblies
In This Chapter
Why use assemblies
Creating assemblies
Positioning parts into assemblies
Working with external references
This chapter serves as an overview of some of the different tools and techniques that are available to SolidWorks users in assemblies. Most importantly, this chapter discusses the various purposes that you might have for creating assemblies. The second emphasis of this chapter is to help you understand various methods for using external references. More than anything, this chapter prepares you for important decisions that you will need to make relating to your modeling methods in SolidWorks found throughout this book.
If you take the SolidWorks training class from a SolidWorks reseller, all assemblies seem to take the same form and have the same function. You may then take this way of working back to your office and start applying it there. However, if you do this, you could be missing out on many other ways of using assemblies. While SolidWorks definitely seems to have a certain orthodoxy in mind for the assemblies functionality, there are actually an array of techniques that you can use to achieve a wide range of goals.
This chapter helps you identify some of the ways in which you can apply SolidWorks assemblies functionality to accommodate your goals and your workflow style. You are encouraged to experiment and evaluate some of these methods to find out what suits your needs best. You don't have to accept the established techniques. In fact, as you will see in this chapter, the established techniques tend to be less efficient, and especially less robust, than some alternative methods when you start making changes to your assemblies.
A lot of these alternative methods have been developed by many different users of other CAD packages over the years and have become universal to some extent. They have been adapted to SolidWorks use in different forms.
Understanding the Purpose of Assemblies
In the physical world, assemblies exist for several reasons:
• Separating materials
• Allowing relative motion
• Reducing material
• Allowing for different manufacturing techniques
• Allowing for disassembly or repair
In a CAD model, you need to follow these physical-world reasons for making individual parts and putting them together in assemblies, but CAD models can also have additional requirements. Independent of the reasons stemming from physical-world requirements, CAD assemblies might have some unique reasons for existing:
• Depicting an assembly process such as order of operations
• Specifying dimensional assembly relationships and tolerances
• Establishing clearances and limits of motion
• Visualizing motion and spatial relationships between parts
• Designing parts in-context
• Creating a parts list for assembly (Bill of Materials, or BOM)
• Creating a parts list for purchasing
• Automating data entry through PDM (product data management)
• Staging renderings
• Creating data for downstream applications such as animation or motion analysis
You can probably come up with a number of additional reasons for making CAD assemblies. In fact, almost as many reasons exist for making assemblies as there are people making those assemblies.
If you are trying to drive product development with a single top-level assembly, you might run into situations where the various functions of the assembly start conflicting with one another. For example, you might have an assembly where a part flexes. It is difficult or impossible to make flexible parts work effectively in SolidWorks with dynamic assembly motion. Another situation might be in-context relations where the parent and child components move relative to one another. Or maybe you need an assembly for a rendering and the assembly has to have multiple instances of in-context components, which can be tricky to manage. You get the picture. You can't always do everything with a single assembly.
It is certainly possible to have multiple assembly files for a single product. In fact, in some cases, it may be necessary. Rendering is probably one of the most common reasons for you to create a new assembly. Conflicts between external references and motion are another common reason to create a new assembly document.
Identifying types of assemblies
The average SolidWorks user thinks an assembly is a collection of parts put together with mates that position parts and may also allow motion. In this kind of assembly, you might use patterns, configurations, in-context techniques, and so on. The goal of the assembly is probably to simulate reality in the way it looks and moves.
Driving an assembly with base part and mates
This is considered “orthodox” Soli...
