SolidWorks 2010 Bible

Part VII: Working with Specialized Functionality

FIGURE 30.17

Using Move Face to extend the length of the barrel of the cast part after the fillets have been removed

Notice how the Web now extends up the side of the barrel. This is the type of edit that would be

clumsy in SolidWorks if it were what you wanted to do. In direct edit, it is the kind of edit that

would be clumsy if it were not what you wanted to do.

This is one of the limitations of direct edit techniques in general — not a limitation of SolidWorks,

but a limitation of the concept. Direct edit cannot make new faces without adding another feature,

and has problems with the intelligent type of face creation that you find in history-based systems.

Direct edit programs are certainly not more powerful than SolidWorks or any other history-based

CAD program. They have weaknesses in different areas, and the weaknesses are more limiting than

SolidWorks history-based weaknesses.

Figure 30.18 shows where the weakness of using the direct edit tools within SolidWorks begins to

show up. The first feature in the part is a revolve that uses a sketch. The last feature in the part is a

Move Face feature that moves the faces created by the revolve. So if you want to change the geome-

try of the barrel, it is controlled by two different features. If you make the sketch a specific size, the

Move Face feature will change it. Move Face can only change relative to a starting point; it cannot

make something a specific dimension.

Some SolidWorks power users consider this double-jeopardy condition sloppy design or bad prac-

tice. You can make a strong case that the direct edit tools should not be used on native SolidWorks

parts, and that you should edit the feature the way it was created. There is certainly a place for that

argument. But I know from my own modeling work that sometimes changing a feature way back

in the tree can have unintended repercussions later in the tree, so using a Move Face feature late in

the tree avoids fixing a lot of propagated errors. Is that a cheap, sleazy cheat? You will have to

decide that for yourself.