SolidWorks 2011 Parts Bible - Matt Lombard [293]
Getting the Flat Pattern
When you need to make a drawing to build a sheet metal part from, getting the flat pattern is an essential part of the process. SolidWorks provides several ways to develop the flattened bend sections in the K-Factor, bend allowance, bend deduction, and bend calculation tables. Getting these values or equations correct is key in making the flat pattern the correct size to produce the finished part accurately. Chapter 21 covers how to use these methods, but you should obtain the actual values from your sheet metal shop.
You create the drawing of a sheet metal part in the same way that you would create one for any other type of part. You can use one of several methods, including the Create Drawing From Part command or dragging and dropping the part onto a drawing. Sheet metal drawings may serve different purposes. Usually a sheet metal drawing requires dimensioned orthogonal views of the finished part, and sometimes it also requires a flat pattern describing the blank the finished part is to be formed from.
To show a view of the flat pattern on a drawing where you already have a sheet metal part, select the view from the FeatureManager or the graphics window, and in the list of views below the Standard Views area of the Orientation panel of the PropertyManager, select Flat Pattern from the list. The Drawing View PropertyManager is shown in Figure 22.1.
FIGURE 22.1
Converting a view of a sheet metal part to a flat pattern
Understanding flat patterns and configurations
When a sheet metal part is put onto a drawing, SolidWorks automatically creates a derived configuration called SM-FLAT-PATTERN. The configuration doesn't exist until the part is put onto a drawing. For a part made with the Base Flange sheet metal method, this derived configuration in Figure 22.2 shows the default arrangement.
FIGURE 22.2
Automatically created derived configuration for the flat pattern
If your part already had multiple configurations, only the config that is showing on the drawing will get a derived flat pattern configuration. If you later show another configuration on the drawing, the derived flat pattern will not be automatically created until you show a flat pattern of that configuration.
Best Practice
You should be careful if you plan to make sheet metal parts with derived configurations for reasons other than the flat pattern. The automatic derived flat pattern configuration functionality may or may not be able to work with your manual or design table-driven derived configuration scheme.
Also be aware that there is a second way to get a flat pattern of a sheet metal part on the drawing. If you use the drop-down list in the Reference Configuration panel of the Drawing View PropertyManager, you can select the derived flat pattern configuration from there. The flat patterns that you get using these two methods may be oriented differently, and if you use the Flat Pattern selection from the More Views options, you will also get bend lines and annotations marking the direction, angle, and inside radius of the bend. The difference between the resulting views of these two methods is illustrated in Figure 22.3.
FIGURE 22.3
Comparing flat pattern views placed by using the More Views options, or by showing the derived flat pattern configuration
Showing bend lines and bend notes
If you show the derived configuration, the bend lines are not included in that view. To turn on the bend lines, you need to go to the FeatureManager for that view, scroll to the Flat Pattern feature, expand it, right-click the Bend Lines sketch, and select Show.
Figure 22.4 shows the drawing FeatureManager with the Bend Lines sketch highlighted.
To get the bend notes to show up, you need to use the Flat pattern view option shown in Figure 22.1. The bend notes are shown in Figure 22.5 and include which direction the bend is formed in, the angle of the bend, and the inside radius of the bend.
Other options for the display of