SolidWorks 2011 Parts Bible - Matt Lombard [320]
The face counts that appear in the color swatches are a very helpful feature that is absent from the Basic draft analysis.
Best Practice
I prefer Face Classification draft analysis because it is the clearest. If I need additional detail regarding other types of faces, then I may run a Steep Face draft analysis as a supplement. The best practice here is not that you follow my favorite type of draft analysis, but that you understand what you need to know and then use the appropriate tools to find this information. This may include running multiple analyses to collect all the necessary information.
Find steep faces
A steep face is defined as a face that transitions from less than the minimum angle to more than the minimum angle. Steep faces are different from straddle faces in that straddle faces are actually positive and negative, while steep faces are either entirely positive or entirely negative. On this part, the dome inside the part is classified as a steep face, as shown in Figure 24.24.
FIGURE 24.24
A steep face
Understanding the Draft Analysis workflow
The workflow for the Draft Analysis tool is as follows:
1. Open a part for which you want to analyze the draft.
2. Select View⇒Display⇒Draft Analysis, or select it from the Evaluate tab of the CommandManager.
3. Select a plane or planar face for the direction of pull, and then set the options you want to use to visualize the draft on your part. The draft colors display immediately after you select the direction of pull.
4. If you want to keep the colors on while you work, click the green check icon. The Draft Analysis icon on the toolbar and menu will display as selected. If you do not want to see the colors anymore, click the red X icon. If you click the green check icon and then later want to turn off the Draft Analysis display colors, you must deselect the Draft Analysis icon in the toolbar or menu.
Using Thickness Analysis
You can run Thickness Analysis in two modes: Show Thin Regions and Show Thick Regions. Of these, Show Thick Regions is the most versatile.
Using the Show Thin Regions option
The Show Thin Regions option, or the “Thinness” Analysis, requires you to input a minimum acceptable thickness. Every face with a thickness above this value is turned a neutral gray, and every face with a thickness below this value is displayed on a graduated scale.
Figure 24.25 shows the PropertyManager for this analysis and its result on the same part used for the draft work in the previous sections.
FIGURE 24.25
Results of the Thinness Analysis
One of the things to watch out for here is that some anomalies occur when you apply this analysis to filleted faces. The faces shown as colored were created by the Shell feature and should be exactly .100 inches thick. However, it does correctly represent the undercut on the end of the part and the thickness of the ribs. A nice addition to this tool would be the identification of minimum thickness faces. Perhaps you can submit an enhancement request.
Using the Show Thick Regions option
The Show Thick Regions option works a little differently from Show Thin Regions. You need to specify an upper thickness limit value, beyond which everything is identified as too thick. In these examples, the nominal wall thickness of the part is shown as .100 inches, and the thick region limit is set to .120 inches. For this type of analysis, the color gradient represents the thicknesses between .100 inches and .120 inches, while in the Thinness Analysis, the color gradient represents the values between .100 inches and 0 inches.
The analysis can produce some anomalous results, especially at the corners, and also in the middle. Again, this is a useful tool, if not completely accurate. You can use it to find problem areas that you may not have considered, but you should certainly examine the results critically.
The Treat Corners As Zero Thickness option should always be selected. I have never seen a situation where selecting it improved the results; in fact, I have found that