SolidWorks 2011 Assemblies Bible - Matt Lombard [43]
Chapter 5: Getting More from Mates
In This Chapter
Learning efficient mating strategies
Performing degrees-of-freedom analysis
Using Advanced and Mechanical mate types
Editing and troubleshooting assembly mates
Choosing mate options
Examining mate best practices
Mating for success tutorial
In SolidWorks assemblies, mates are the basic units that make everything work together. When properly handled, mates enable your assembly to react predictably to changes in parts in exactly the same way that sketch relations drive changes in part features. As a result, mates and sketch relations often have the same function and even the same weaknesses to watch out for.
This chapter goes one step further with mates, by not just simply putting parts together with Coincident and Concentric mates, but also mating parts when tolerances, gaps, and symmetry become issues. You will also learn about the more advanced mate types that may be useful for special situations.
One of the assumptions made in this chapter is that assembly mates are not just used for positioning parts, but also for motion. Making motion work takes a little more than just establishing the right spatial relationship between parts; it usually also involves analyzing the open degrees of freedom.
Some users take a static approach to putting parts together into assemblies, by simply placing parts at the correct X- and Y- coordinates without assigning any relationships to the parts around them. This defeats most of the purpose of creating parametric, associative assemblies in the first place. Assembly mates are an extremely powerful tool for enabling your assemblies to react predictably to change.
Applying Mates
An average assembly of 100 parts is likely to have almost 300 individual mates. If you created these parts one at a time, taking perhaps a minute for each mate, you would spend five hours just applying mates. You should avoid applying mates whenever possible — assuming you still get the correct results — because this allows you to spend more time doing something else. In this section, you will learn efficient mating strategies, as well as speedy techniques.
As you apply mates to parts in your assembly, keep in mind that SolidWorks has high- and low-risk mating schemes (see Chapter 1). High-risk schemes generally involve mate techniques that are easier, but are also more likely to have problems later in the evolution of your model, such as lost references or conflicts with other mates. More stable mating schemes favor reference geometry such as planes and axes, and possibly sketches over model faces and edges.
Mating through the Mate PropertyManager
The Mate PropertyManager is the default method for applying mates, and you used it briefly in Chapter 4. The Mate PropertyManager interface is shown in Figure 5.1. You can create mates by pre-selecting entities before applying the Mate command or selecting them after you open the Mate PropertyManager. The three types of mates are Standard, Advanced, and Mechanical.
FIGURE 5.1
The Mate PropertyManager interface
Understanding the mate workflow
If you make a lot of mates, it is important to have an efficient rhythm when working with the interface. Assuming you have the Mate PropertyManager already active, the most efficient way to use the Mate interface is as follows:
1. Click the first entity.
2. Click the second entity.
3. Click OK on the right mouse button (RMB) cursor icon to accept the default.
Alternatively, if the automatic default mate type is not the mate that you want to apply, select it from the popup list, shown in Figure 5.2.
FIGURE 5.2
The Mate selection popup list
4. Click the green check mark icon on the popup list.
5. Repeat Steps 1 to 4.
6. After the last mate, press Esc, the green check mark icon, or the red X icon in either the PropertyManager or the confirmation corner (located in the upper-right corner of the graphics area).
Changing the view and