SolidWorks 2011 Parts Bible - Matt Lombard [115]
Be careful of the rock-paper-scissors game that you inevitably are caught up in when modeling plastic parts and deciding on the feature order of fillets, draft, and shell. Most fillets should come after draft, and large fillets should come before the shell. Draft may come either before or after the shell, depending on the needs of the area that you are dealing with on the part. In short, there is no single set of rules that you can consistently apply and that works best in all situations.
Dealing with a large number of fillets
Figure 7.28 shows a model with a bit of a filleting nightmare. This large plastic tray requires many ribs underneath for strength. Because the ribs may be touched by the user, the sharp edges need to be rounded. Interior edges need to be rounded also for strength and plastic flow through the ribs. Literally hundreds of edges would need to be selected to create the fillets if you do not use an advanced technique.
FIGURE 7.28
A plastic tray with a large number of fillets
Selecting entities
Some of the techniques outlined previously, such as face and feature selection, can be useful for quickly filleting a large number of edges. Another method that still selects a large number of edges, but is not as intuitive as the others, is window selection of the edges. To use this option effectively, you may want to first position the model into a view where only the correct edges will be selected, turn off the Select Through Faces option, and use the Edges selection filter.
Using the FilletXpert
The FilletXpert is a tool with several uses. One of the functions is its capability to select multiple edges. A part like the one shown in Figure 7.28 is ideal for this tool. To use the FilletXpert, click the FilletXpert button in the Fillet PropertyManager. Figure 7.29 shows this. When you select an edge, the FilletXpert presents a popup tool bar giving you a choice of several selection options. Notice that Figure 7.29 shows the majority of the edges selected that are needed for this fillet.
FIGURE 7.29
Using the FilletXpert selection technique
The FilletXpert is also a tool that automatically finds solutions to complex fillet problems, particularly when you have several fillets of different sizes coming together.
The Corner tab of the FilletXpert enables you to select from different corner options, which are usually the result of different fillet orders. To use the CornerXpert, make sure the FilletXpert is active; then click the corner face, and toggle through the options.
Using preview
I like to use the fillet preview. It helps to see what the fillet will look like, and perhaps more important, the presence of a preview usually (but not always) means that the fillet will work.
Unfortunately, when you have a large number of fillets to create, the preview can cause a significant slowdown. Deselecting and using the Partial Preview are both possible options. Partial Preview shows the fillet on only one edge in the selection and is much faster when you are creating a large number of fillets.
Performance
For rebuild speed efficiency, you should make fillets in a minimum number of features. For example, if you have 100 edges to fillet, it is better for performance to do it with a single fillet feature that has 100 edges selected rather than 100 fillet features that have one edge selected. This is the one case where creating the feature and rebuilding the feature are both faster by choosing a particular technique. (Usually if it is faster to create, it rebuilds more slowly.)
Best Practice
Although creation and rebuild speed are in sync when you use the minimum number of features to create the maximum number of fillets, this is not usually the case. (There had to be a downside.) When a single feature has a large selection, any one of these edges that fail to fillet will cause the entire feature to fail. As a result, a feature with