SolidWorks 2011 Parts Bible - Matt Lombard [285]
Configurations cannot be used with forming tools like they can with library features, although you can change dimensions by double-clicking the Forming Tool icon in the sheet metal part FeatureManager. Forming tools are suppressed when the part is flattened.
Special techniques with forming tools
One application of forming tools that is asked for frequently is the cross break to stiffen a large, flat sheet metal face. SolidWorks has a cosmetic cross break which I discuss next. Cross breaks are clearly not something that SolidWorks can do using straight bends, but a forming tool can do it.
You can create the forming tool by lofting a rectangle to a sketch point on a plane slightly offset from the plane of the rectangle. This creates a shallow pyramid shape. Open the part from the material on the DVD for Chapter 21 called Chapter 21 – Cross Break Sheet Metal.sldprt to examine how this part was made. Figure 21.32 shows the Cross Break forming tool applied to a sheet metal part.
FIGURE 21.32
The Cross Break forming tool applied to a part
Cross breaks
Using a forming tool to create a cross break is overkill for most situations. You may need to do it if you need to actually show the indented geometry. The Cross Break feature is essentially a cosmetic cross break, and it enables you to specify the radius, angle, and direction used to create the cross break. It does not actually change the part geometry at all, but it does add two curve-like display entities.
When you place a Cross Break feature, you have the option to edit the sketch profile that creates the cross. This sketch has two intersecting lines. You cannot add more lines; the feature will fail if you have more than two lines in the sketch. (For example, if you wanted to put three breaks across a hexagonal face, the software will not allow this.) The lines do not have to end at a corner, but they do have to end at an edge. If the lines extend past or fall short of an edge, the feature will display a red X error icon, but it still creates the break lines where the sketch lines are.
Figure 21.33 shows the Cross Break PropertyManager and a part to which a cross break was applied. Notice that you can see the break lines through the solid, much like curves or cosmetic threads.
FIGURE 21.33
Creating a cross break
The Cross Break feature shows up in the FeatureManager just like any other feature, not like a cosmetic thread, which is the only other entity in the software that the cross break much resembles.
Form across bends
A second special technique is a gusset or a form that goes across bends. This can be adapted in many ways, but it is shown here going across two bends. I cannot confirm the practicality of actually manufacturing something like this, but I have seen it done.
The technique used here is to call the single long flat face of the forming tool the Stopping Face. The vertical faces on the ends and the fillet faces must be selected in the Faces to Remove selection box. The fillets of the outside of the forming tool also have to match the bends of the sheet metal part exactly. You may need to edit this part each time you use it, unless you apply it to parts with bends of the same size and separated by the same distance.
When you place the tool on the sheet metal part, you must place it accurately from side to side to get everything to work out properly. This part is in the same location as the Cross Break file and is called Chapter 21 – Form Across Bends Sheet Metal.sldprt. Figure 21.34 shows the tool and a part to which it has been applied.
FIGURE 21.34
Forming across bends
Using the Lofted Bends feature
The Lofted Bends feature enables you to create transitions between two profiles. The range of functionality available through the Loft feature is not available