SolidWorks 2011 Parts Bible - Matt Lombard [283]
When finished, the Corner Trim feature places itself after the Flat Pattern feature in the FeatureManager. It similarly follows the suppress/unsuppress state of the Flat Pattern feature. When the Break Corner feature is used on its own, it is placed before the Flat Pattern feature. With this in mind, it seems best to use Break Corner as a separate feature unless it is being used specifically to alter the Flat Pattern in a way that cannot be done from the folded state.
Break Corner on its own is primarily used to remove sharp corners using either a chamfer or a rounded corner. This tool is set up to filter edges on the thickness of sheet metal parts, which is useful, because these edges are otherwise difficult to select without a lot of zooming. Break Corner can also break interior corners.
One of the main functions of the Corner Trim feature is to apply bend relief geometry to the Flat Pattern. The three available options are Circular, Square, and Bend Waist. These options are shown in Figure 21.26.
FIGURE 21.25
The Corner Trim PropertyManager, including the Break Corner Options panel
FIGURE 21.26
Applying the Corner Trim Relief options
Mirroring and patterning in sheet metal
Most sheet metal features can be patterned or mirrored following the same logic as normal SolidWorks parts. Figure 21.27 shows a part with some features mirrored.
FIGURE 21.27
Mirroring some features on a sheet metal part
Mirroring sheet metal features
Notice that not all of the features are mirrored, though. In particular, the Corner Break and the Sketched Bend would not mirror. When you get into a situation where individual features don't mirror, you have two options, just like you would with mirroring a normal SolidWorks part: re-create the features on the other side manually or mirror the body rather than the features.
Figure 21.28 shows the same part from Figure 21.27 but modeled by mirroring the body instead of just the features, so all of the geometry is symmetrical. You can use this technique along with changing the feature order to make asymmetrical parts when the need arises.
FIGURE 21.28
Mirroring the entire sheet metal body
Patterning sheet metal features
Patterning also works for multiple sheet metal features. Figure 21.29 shows the patterned tabs with holes and hems. Controlling the bend placement of the first feature changes all of the patterned instances. This works nicely, especially because most patterns in sheet metal are going to be less demanding than general patterns.
FIGURE 21.29
Patterning multiple features in sheet metal
If you examine the part from the DVD (shown in Figure 21.29), it also contains a mirror feature that mirrors a Closed Corner feature. To me, this is very reasonable pattern/mirror functionality from SolidWorks.
Forming tool feature
Forming tools in SolidWorks enable you to place features that are not formed on a brake press. These are features that are not straight-line bends but rather punched, drawn, formed, lanced, sheared, or otherwise deformed material.
One of the important things to understand about forming tools is that they do not stretch the material in the SolidWorks part in the same way that happens in a real-life forming operation. In real life, material is thinned when it is punched, stamped, or drawn. In SolidWorks, the thickness of a sheet metal part remains the same, regardless of what happens to it. For this reason, you need to be careful when using mass properties of sheet metal parts or doing stress analysis of parts that have formed features. You might consider taking your part