SolidWorks 2011 Assemblies Bible - Matt Lombard [139]
FIGURE 16.15
Changing the defaults for density and crosshatch
Broken-Out Section View
The Broken-Out Section View is a view type that alters an existing view rather than creating a new view. It also requires a closed loop sketch. The Broken-Out Section View is very useful in assembly views where parts are obscured by other parts, particularly when a set of parts is inside a housing and you want to show the inside parts without hiding the housing. Of course, you can also use a Broken-Out Section View on parts with internal detail.
A Broken-Out Section View acts like a cut that is created from the drawing view. Any faces created by the cut are hatched. Figure 16.16 shows a simple assembly view using a Broken-Out Section View. On the left is the view with the driving sketch (in this case, a closed loop spline), and on the right is the finished view. You cannot create a Broken-Out Section View using existing Detail, Section, or Alternate Position Views.
A Broken-Out Section View requires you to specify a depth for the break. You can use an edge selected from a different view or a distance to specify the depth. In the case of the broken-out section, the depth is into the screen, while with the regular section the depth is measured as a distance perpendicular to the section line.
FIGURE 16.16
A Broken-Out Section View
Drawing the closed loop
A Broken-Out Section View is initiated from an existing view either with or without a pre-drawn closed loop. If the loop is pre-drawn, then you must select it before clicking the Broken-Out Section toolbar button on the Drawings toolbar or accessing the command by choosing Insert⇒Drawing View⇒Broken-Out Section.
If the view does not have a pre-drawn, pre-selected loop, then initiating the function activates the spline sketch tool. It is not necessary to use a spline as the closed loop for this view type, but a Broken-Out Section View is traditionally created with a freehand sort of boundary, even when drawn manually.
If the loop is closed in an uninterrupted workflow, then after the last spline point is drawn, joining the spline back to itself, the Section Scope dialog box appears. This enables you to select any parts that are not to be sectioned. It is customary to avoid sectioning shafts, screws, or other cylindrical components.
The recommended workflow is to initiate the function from the toolbar, use the spline to create the closed loop, and not pre-draw a loop. This makes everything flow more smoothly, and you create the view surprisingly quickly. If you must use a sketch tool other than the spline, then you must pre-draw it. Even if you simply change sketch tools when the Broken-Out Section View automatically activates the spline, because the workflow has been broken, creating the closed loop does not automatically display the Section Scope interface.
Selecting the depth
After you make the Section Scope selections, the next step is to set the depth of the cut. You can do this in one of several ways. A Broken-Out Section View is usually applied to the center of a hole if available, or in other ways that show the view as cleanly as possible. If you know the depth of the cut that you want to make, then you can type it in as a distance value. Of course, that raises the question, “Distance from what?” The answer seems to be “from the geometry in the view that would come the farthest out of the screen toward the user.” Users most often choose the distance when it does not matter exactly how deep the cut goes or exactly where it cuts, but it gives a relative position.
In situations when you want to cut to the center of a particular feature or up to an edge, it is far easier to simply select the geometry from a drawing view. For example, Figure 16.17 shows the PropertyManager