SolidWorks 2011 Parts Bible - Matt Lombard [174]
Using Evaluation Techniques
You can use evaluation techniques to evaluate geometry errors, demonstrate the manufacturability of a given part, or to some degree quantify aesthetic qualities of a given part, or section of a part. I discuss evaluation techniques here because the design cycle involves iterations around the combination of create-evaluate-edit-evaluate functions. I discuss the following techniques in this section:
• Verification on rebuild
• Check
• Zebra Stripes/RealView/Lights and specularity
• Curvature display
• Deviation analysis
• Tangent Edges as Phantom
• Geometry Analysis
• Feature statistics
• Curvature comb
• DFMXpress (Design For Manufacturability)
• SimulationXpress
Many of these techniques apply specifically to plastic parts and complex shapes, but even if you do not become involved in these areas of design or modeling, these tools may help you to find answers on other types of models as well.
A special tab called Evaluate appears in the CommandManager; this tab has much of the functionality that is discussed in this chapter. You can use the commands on this tab to evaluate parts in several ways. Some focus on plastic parts or thin-walled parts or symmetric parts, and so on. Most of these tools are from the Tools toolbar but are found on the Evaluate tab in the Command Manager.
Using Verification on rebuild
Verification on rebuild is an option that you can access by choosing Tools⇒Options⇒Performance⇒Verification on rebuild. Under normal circumstances (with this setting turned off), SolidWorks checks each face to ensure that it does not overlap or intersect improperly with every adjacent face. Each face can have several neighbors. This option is shown in Figure 12.7.
FIGURE 12.7
The Verification on rebuild option
With the setting selected, SolidWorks checks each face with every other face in the model. This is a better check than with the setting off but greatly increases the workload. The switch is deselected by default to prevent rebuild times from getting out of control. For most parts, the default setting is sufficient; however, when parts become complex, you may need to select the more advanced setting.
If you are having geometry or rebuild error problems with a part and cannot understand why, then try turning Verification on rebuild on and pressing Ctrl+Q. Ctrl+Q applies the Forced Rebuild command and rebuilds the entire design tree. Ctrl+B, or the Rebuild command, only rebuilds what SolidWorks determines needs to be rebuilt.
If you see additional errors in the design tree that were not there before, then the combination of Verification on rebuild and Forced Rebuild has identified problem areas of the model and the features that caused the errors failed. If not, then your problem may be elsewhere. You still need to fix any errors found this way.
Performance
For speed reasons, it is normal practice to turn Verification on rebuild off, and to use it selectively to check models with potential errors. The type of speed degradation that you can see is dependent on the number of faces and bodies in the model. Some of the performance degradation as relates to patterns is documented in Chapter 9.
Using the Check tool
Check is a tool that checks geometry for invalid faces and other similar geometry errors. It is also often used to find open edges of surface bodies, short edges, and the minimum radius on a face or entity. I usually apply the Check tool before selecting the Verification on rebuild option. The Check tool points to specific face or edge geometry (not features or sketches) that is the cause of the problem. When the Check tool finds general faults, the locations it points to may or may not have something obvious to do with a possible fix.
Much of the time, the best tool for tracking down geometry errors is the combination of experience and intuition. It is not very scientific, but you come to