In this article we are going to explore how the feature is applied to the part to create the appropriate relief. We are also going to explain what the relief dimensions and some of the relief options means.
For the circular and square reliefs their sizes are easy to figure out. The circular relief dimension specify the radius of the relief and the square relief its side dimension. Fig. 1, shows also how the circular and square reliefs are applied when the “Centered on bend lines” is unchecked.
When the “Centered on bend lines” is not selected the outer edges of the flanges meet the center of the circular and square relief.
For the obround relief, we use a “slot type” of cut to create the relief. Its dimensions are shown in Fig. 2 (center). Its positional cut in the flat pattern is such that the center of the inner slot arc matches the inner bend region limit of the bends. Fig. 2 (center and right)
Centered on Bend Lines Option
When the option “Centered on bend lines” is checked, the center of the square and circular reliefs match the intersection of the bend lines Fig. 3
For the obround relief, the bend lines intersection meets at the center of the slot.
Ratio to Thickness Option
This option is straight forward. Assume the thickness is 1 mm, a “Ratio to Thickness” equals to 4 will create a 4 mm per side square relief Fig.5
For the obround relief the “Ratio to thickness” options works in a similar manner. For a 3 width ratio, when the part is 1 mm in thickness, the width of the slot will be 3 mm. As Fig. 6 shows, when the “Ratio to thickness” is used in a obround relief, the width ratio has more influence on the shape of the relief than the length ratio.
The “length” ratio (3.2) Fig. 7, only affects the relief within a narrow margin. At length ratio equal to 3.2 –this is the minimum possible length ratio , — the relief will look like more rounded.
Fig. 8 shows the obround relief with the “Centered on bend lines” and “Ratio to thickness” options. The bend lines intersection will be at the center of the slot.
Originally posted in the SOLIDWORKS Tech Blog.