SolidWorks 2011 Parts Bible - Matt Lombard [48]
Note
PropertyManagers for sketch tools such as Mirror, Convert Entities, Sketch Fillet, and Intersection Curve now include a selection box for the entities to be used in the operation. The Offset PropertyManager is one that is conspicuously missing this functionality.
The workflow for the sketch tools with the selection boxes generally feels interrupted, in comparison to the workflow in SolidWorks versions before the selection boxes existed. To overcome this problem, you can deselect the push pin, and on the next execution of the tool, preselect the entities that would go into the selection box and then click the toolbar icon.
The Convert Entities tool converts edges, curves, and sketch elements from other sketches into entities in the current sketch. When edges are not parallel to the sketch plane, the Convert Entities feature projects them into the sketch plane. Some elements may be impossible to convert, such as a helix, which would produce a projection that overlaps itself. Sketch entities created using Convert Entities get an On-Edge sketch relation.
The Offset Entities tool works like the Convert Entities feature, except that it offsets the sketch to one side or the other of the projection of the original edge, sketch, or curve. Figure 3.11 shows the interface for this command.
FIGURE 3.11
The Offset Entities interface
The options available in the Offset Entities interface are as follows:
• Add dimensions. Constrains offset sketch entities. Instead of the On-Edge relations, Offset Entities creates an Offset sketch relation that cannot be re-created manually.
• Reverse. Changes the direction of the offset.
• Select chain. Selects continuous end-to-end sketch entities.
• Bi-directional. Offsets to both sides simultaneously.
• Make base construction. If you are offsetting sketch entities within the active sketch, this option converts the original sketch entities to construction sketch geometry.
• Cap ends. Is available only when you have selected the Bidirectional option. Capping the ends with arcs is an easy way to create a slot from a sketch of the centerline. This function works with all sketch entities; it is not limited to straight slots. Figure 3.12 shows examples of the Cap ends option.
Caution
The Offset Entities command may fail if the offset distance is greater than the smallest radius of curvature, and you are attempting to offset to the inside of the arc.
In addition to the bidirectional offset with capped ends, SolidWorks also has slot sketch entities for straight and curved slots, which are covered later in this chapter. Composite slots (made of a combination of straight and curved sections) still require the offset method.
FIGURE 3.12
The results of using offset entities cap ends
The Trim tool is actually several functions rolled into one, and it is an extremely powerful tool for editing sketches. Trim Entities allows several methods for trimming, as well as extending and deleting sketch entities. Figure 3.13 shows the PropertyManager interface for this function.
FIGURE 3.13
The Trim interface
• Power trim. Trims by dragging a cursor trail over multiple entities. The entities that you drag the cursor over are trimmed back to the next intersecting sketch entity. Each time you trim an entity, a red box remains until you trim the next entity. If you backtrack with the cursor and touch the red box, this trim is undone. This option is best used when you need to trim a large number of entities that are easy to hit with a moving cursor. Figure 3.14 shows the Power Trim feature in action.
You can also use power trim to extend sketch entities along their paths by dragging the endpoints. Regular dragging can also change the position or orientation of the rest of the entity, but by using the Power trim feature you affect only the length.
Figure 3.14
The Power trim feature in action
• Corner. Trims or extends two selected entities to their next intersection.