SolidWorks 2011 Assemblies Bible - Matt Lombard [187]
2. Draw a sketch that represents the outer shape of the structure, as well as inner structural members.
3. Use the GridSystem PropertyManager to establish the number of levels (floors), the default height for the levels, and the specific height for each level.
4. Click OK in the PropertyManager and watch SolidWorks build the GridSystem.
The following sections include the details for each of the above steps.
Starting the GridSystem feature
The GridSystem toolbar icon is listed as part of the Feature toolbar, although it does not appear there by default. If you want to add the GridSystem icon to any toolbar, choose Tools⇒Customize⇒Commands, and select it from the end of the list of icons for the Feature toolbar.
You can access the GridSystem feature through the menus by default, but it is in a different location. Through the menus, choose Insert⇒Reference Geometry⇒GridSystem.
Creating the sketch
When you start the GridSystem feature, SolidWorks puts you into a 2D sketch on the Top (XZ) plane. The software is waiting for you to create a sketch with some specific properties. This sketch essentially represents the layout of the structural members forming one level of the structure. Figure 22.5 shows a sample sketch. The sketch is dimensioned in inches, but you can also use other units, such as feet.
FIGURE 22.5
Sketching a sample structural layout
Notice also that annotations label the intersections of the lines with letters for the X direction and numbers for the Z direction. This is the method structural engineers use to identify the columns in the structure. The column in the center of the sketch shown in Figure 22.5 would be called 1B. SolidWorks automatically generates these column line labels when you select the Autonumber Balloons option at the bottom of the GridSystem PropertyManager.
There appear to be several rules for the sketch that are not obvious. First, all of the lines are planar, and either horizontal or vertical within the sketch. Presently, SolidWorks does not allow you to make a circular structure, or use the sketch to lay out something like a power-line tower. This is not to say you could not add diagonal members later, but you cannot use them as part of the initial layout for the GridSystem.
Using the GridSystem PropertyManager
When you are done, exit the sketch by clicking the sketch icon in the Confirmation Corner (in the upper-right corner of the graphics window). The GridSystem PropertyManager appears, as shown in Figure 22.6.
FIGURE 22.6
Setting up the grid in the PropertyManager
The features in the GridSystem PropertyManager are straightforward. The default level height of 118.11023622 inches is a conversion of the default 3-meter height that SolidWorks uses. Notice that you can customize the height of each level; for example, if Level 3 has some specialized equipment that needs more room than the standard level height, you can easily specify this as part of the design.
The 3DSketch Split Lines option controls whether the columns that extend through all levels of the grid will be continuous from top to bottom or will be split at each level. Which option you select depends mainly on what you plan to do with the GridSystem. If you plan to use it to create a weldment, you may want to split the lines. If you plan to simply extrude shapes the entire height of the structure, you may prefer to not split them.
Understanding the GridSystem output
The GridSystem creates a single feature in the FeatureManager with a number of derived sketches and planes, as shown in Figure 22.7. All of the additional features are listed as parents of the GridSystem and indented underneath it in the FeatureManager.
You have already looked at the derived sketches and planes, one for each level, created at the appropriate heights. A derived sketch is simply a parametric copy of the original sketch, placed on a different plane. If the original sketch changes, the derived copies are also updated. You