Part VII: Working with Specialized Functionality
The specific formulas for finding these numbers are not as important as an intuitive grasp of what
the numbers mean and how they are used, at least in relation to using SolidWorks to model sheet
metal parts. The numbers used to fill out Bend Tables using K, BA, or BD values are typically taken
from experimentally developed tables.Auto Relief
Auto reliefs were formerly called Bend reliefs. You can specify three different Auto relief options to
be applied automatically to bends that end in the middle of material. These options are illustrated
in Figure 29.7.FIGURE 29.7
The three Auto relief configurations: Rectangular, Tear, and ObroundRectangular Tear ObroundFor the Rectangular and Obround types, you can control the width and the distance past the tan-
gent line of the bend through the Relief Ratio selection box, which is immediately below the type
selection box in the Sheet Metal PropertyManager. This ratio is the width of the relief divided by
the part thickness. For the Rectangular relief, a ratio of .5 and a thickness of .050 inches means
that the relief is .025 inches wide and that it goes .025 inches deeper into the part beyond the tan-
gent line of the bend. The Obround relief goes slightly deeper because it has a full radius after the
distance past the tangent line of the bend, and so it essentially goes a total of one full material
thickness past the tangent line.The Tear relief is simply a face-to-face shear of the material with no gap.Flat Pattern feature
The Flat Pattern feature is added automatically to the end of the tree when the Base Flange feature
is added. This feature is used to flatten the sheet metal part when the feature is unsuppressed. The
Flatten toolbar button acts as a toggle to unsuppress or suppress the Flat Pattern feature in the tree.
It may be a little confusing, but the Flatten toolbar button and the flat-pattern feature in the
FeatureManager refer to the same functionality. As mentioned earlier, the Flat Pattern has a couple