SolidWorks 2011 Parts Bible - Matt Lombard [131]
The Flex feature is very conscious of separate bodies. In some cases this can be helpful, but in default situations when there is only one body in the part, it can be annoying. Remember to select the body to be affected in the very first selection box at the top of the PropertyManager.
Tip
If you want to bend only one of the tabs on the grommet, then the best solution is to split the single body into two bodies and flex only one of the bodies. The examples shown for twisting and stretching use this technique.
Cross-Reference
Splitting a single body into multiple bodies is covered in Chapter 19.
You can place the trim planes by selecting a model vertex, by dragging the arrow on the plane, or by typing in a number. Be careful when dragging the plane arrows because dragging the border of the plane drags the flex value for the feature. (Dragging the plane in a bending operation is like changing the angle or radius for the bend.)
Using the triad can be very tricky. Moving the triad in the bending option moves the axis of the bend, and so it determines whether the bend will compress or stretch the material. The position of the triad also determines which side of the bent body will move or stay stationary, or if both sides will move. Placing the triad directly on a trim plane causes the material outside the bend on that side of the trim plane to remain stationary.
I highly recommend taking a look at the models that are provided with this chapter to examine the various functions of the Flex feature more carefully. The model uses configurations, which are covered in Chapter 11.
Applying the Deform feature
Like the Flex feature, the Deform feature changes the shape of the entire model without regard to parametrics, features, history, or dimensions. Some software packages call this technique global shape modeling. Also like Flex, Deform works on surface bodies as well as solids. Deform can also handle imported geometry as well as SolidWorks native parts. Model complexity is not an issue unless the part runs into itself during deformation.
The Deform feature is also another feature type that you may not use to actually design anything, but that you may use to show a model in a deformed state.
Best Practice
Typically, if you want a model to have a certain shape, then you need to intentionally and precisely model it with that shape. The problem with using deform and flex geometry for actual design data is that they both create fairly approximate geometry, and this process yields a result that is not completely intentional. The shape that you finally achieve is the result of arbitrary uncontrolled function of the feature, not necessarily creating a shape that you had clearly envisioned beforehand.
Deform has three types:
• Point. This type deforms a portion of the model by pushing a point and the geometry around it.
• Curve to curve. The most precise and useful deform type, this type selects an existing edge and forces the edge to match a curve.
• Surface push. This type of deform, while conceptually a very interesting function, is nearly unusable in practice. The part is deformed into a shape vaguely resembling an intermediate shape between the existing state of the part and a “tool” body.
Figure 8.17 shows the PropertyManager interface for the Deform feature. The interface is different for each of the three main types, and also changes, depending on selections within the individual types. The interface shown is for the Curve to curve type because I believe this to be the most useful type.
FIGURE 8.17
The PropertyManager interface for the Curve to curve deform
Looking at Point deform
The Point deform option enables you to push a point on the model, and the model deforms as if it were rubber. Figure 8.18 shows the PropertyManager, as well as a before-and-after example of the Point deform function. The key to using this feature is to ensure that the Deform region option is unselected. Aside from that, you just have to use