SolidWorks 2011 Parts Bible - Matt Lombard [186]
4. Select the type of screw. For example, a counterbored hole can accommodate a socket head cap screw or a hex head screw, among others.
5. Select the size of the screw. This is not the size of the hole. If you select a 1⁄4-inch hole, the hole will not measure .250 inch; it will have the nominal diameter to fit a 1⁄4-inch screw. You also have the option to select Show Custom Sizing to enter in custom dimensions for the hole directly, in case the hole is meant to accommodate something other than a standard-sized fastener.
6. Select the fit of the screw into the hole, such as normal, loose, or close.
7. Select the end condition of the hole.
8. Select options for clearance and countersinks or edge breaks.
Alternatively, you can use or assign a favorite. A favorite is a hole with settings that you use frequently and want to save. I discuss these later in this chapter.
You can use Custom Sizing when you need a hole with nonstandard dimensions.
9. Locate the center of the hole or holes. Switch to the Positions tab of the Hole Wizard PropertyManager to do this. You can place multiple holes in a single Hole Wizard feature, even on different faces and curved faces. I address the specifics of this step later in this chapter. Note that if you want to place holes on multiple faces, non-planar faces, or at different heights, you will need to do this with a 3D Sketch, on the Positions tab.
10. Click OK to accept the type, size, and placement of the hole. Figure 13.1 shows the Hole Wizard PropertyManager interface.
Figure 13.1
The Hole Wizard PropertyManager interface
Defining the anatomy of a Hole Wizard hole
Hole Wizard holes are made of two sketches: a center placement sketch and a revolved cut profile. Figure 13.2 shows a simple part with an expanded Hole Wizard feature. Notice that the feature is named for the size and type of the hole.
FIGURE 13.2
A design tree containing a Hole Wizard hole
Using the placement sketch
The placement sketch is listed first under the Hole Wizard feature. It contains one or more sketch points marking the hole centers. It may also contain construction geometry with relations and dimensions to parametrically locate the hole centers. The placement sketch may be a 2D or a 3D sketch. A 3D sketch is more powerful, but also more complex and prone to difficulties. I discuss placement sketches in more detail in the next section.
Using the hole sketch
The revolve profile sketch is not on an identifiable sketch plane that you can reuse for other features. You can change the sketch dimensions outside of the wizard interface, and if you later use the wizard to edit it, then the changes appear in the Custom Sizing panel. Figure 13.3 shows the Custom Sizing panel with the changed counterbore diameter highlighted.
FIGURE 13.3
The Custom Sizing area of the Hole Specifications panel
If you change any of the options in the Options panel, the revolved sketch profile is altered to accommodate the change. For example, if you select the check box for a near side countersink, the sketch changes to add a line for the countersink; a separate chamfer feature is not added.
Using 2D versus 3D placement sketches
In SolidWorks 2010, SolidWorks changed the Hole Wizard so that it defaults to a 2D sketch. Pre-selection of a plane or planar face is still recommended because it eliminates a step later on, but it is no longer required in order to avoid being forced into a 3D placement sketch. Three-dimensional placement sketches are still available and still useful, but because they are so much more difficult to use and rarely truly needed, SolidWorks decided to change the default to a 2D sketch.
Three-dimensional placement sketches are needed for Hole Wizard holes if you have a set of similar holes that are placed on different levels or are always perpendicular to non-planar surfaces. If you need 3D placement sketches, they are still available, but they are no longer the default. To use a 3D placement sketch in a new Hole Wizard feature, just click the 3D Sketch