SolidWorks 2007 bible phần 9 pdf

FIGURE 30.6 Selecting a straight edge for a conical part Select one of these edges in the Fixed Face/edge selection box 859 Using the Insert Bends Method for Sheet Metal Parts 30 41_080139 ch30.qxp 3/26/07 5:38 PM Page 859 Mixing Methods Once you have used the Insert Bend tool on a part, it is not automatically excluded from using some of the more advanced tools that are available through the Base Flange method, unless it is a cylindrical or conical part. A Flat Pattern feature is added to the bottom of most feature trees, and the presence of this feature is what signifies that the current part has now become a sheet metal part to the Base Flange features. However, it is recommended that you avoid mixing the different techniques to flatten parts, for example, suppressing bends under Flatten and Process Bends, as well as using the Flat Pattern. Tutorial: Working with the Insert Bends method for sheet metal parts The Insert Bends method has been relegated mainly to duty for specialty functions. Gain an under- standing of how this method works by following these steps: 1. Create a new blank part. 2. On the Top plane, open a sketch and sketch a rectangle centered on the Origin 12 inches in the Horizontal direction and 8 inches in the Vertical direction. 3. Extrude the rectangle 1 inch with 45 degrees of draft, Draft Outward, in Direction 1, and in Direction 2 extrude 2 inches with no draft. The two directions should be opposite from one another. 4. Shell out the part to .050 inches, selecting the large face on the side where the draft has been applied. The part should now look like Figure 30.7. FIGURE 30.7 The part as of step 4 860 Working with Specialized Functionality Part VII 41_080139 ch30.qxp 3/26/07 5:38 PM Page 860 5. Use the Rip feature to rip out the four corners. Allow the Rip to rip all corners in both directions. The part should now look like Figure 30.8. FIGURE 30.8 Ripping the corners 6. Draw a rectangle on one of the vertical faces of the part, as shown in Figure 30.9. FIGURE 30.9 Adding a sketch for the cut Completed rip 861 Using the Insert Bends Method for Sheet Metal Parts 30 41_080139 ch30.qxp 3/26/07 5:38 PM Page 861 7. Use the sketch to create a Through All cut in one direction. Notice that the Normal Cut option is on by default. Examine the finished cut closely; notice that it is different from the default type of cut because it is not made in a direction normal to the sketch, but rather in a direction normal to the face of the part. Details of this are shown in Figure 30.10. FIGURE 30.10 Using the Normal Cut option 862 Working with Specialized Functionality Part VII 41_080139 ch30.qxp 3/26/07 5:38 PM Page 862 8. Click the Flatten button on the Sheet Metal toolbar. Notice that the Flat Pattern feature becomes unsuppressed and that the Bend Lines sketch under it is shown. This works just like it did in the Base Flange method. The finished part is shown in Figure 30.11. FIGURE 30.11 The finished part with the Flat Pattern feature unsupressed Summary The Insert Bends method was convoluted, requiring a lot of jumping around between rollback states, and reordering to place features in the proper order so that everything appears on the flat pattern where it belongs. The new tools are far easier to use, but do not replace all of the function- ality of the old technique. 863 Using the Insert Bends Method for Sheet Metal Parts 30 41_080139 ch30.qxp 3/26/07 5:38 PM Page 863 41_080139 ch30.qxp 3/26/07 5:38 PM Page 864 W eldments in SolidWorks are built on driving structural profiles along sketch entities in a multibody part environment. Weldment members can be curved, you can make them using standard or custom profiles, and you can build them from both 2D and 3D sketches. A Cut list within the part keeps track of how much of each profile is needed to fabricate the weldment. Weldments are specialized parts that are similar in some ways to sheet metal parts. You can use weldments for round or rectangular tubular structures, struc- tures made from channels, flanged sections, standard or custom shapes, gus- sets, and end caps, and they can also represent weld beads in the part. You can also use weldments to create structures that are bolted together, struc- tural aluminum extrusion frames, and vinyl window frames, and you can put them into assemblies with other parts such as castings, sheet metal, and fab- ricated plate. Sketching in 3D Three-dimensional sketching is important for creating weldments in SolidWorks. Structural frames are a large part of the work that is typically done using weldment functionality in SolidWorks, and frames are best repre- sented as 3D wireframes. You can do this with a combination of 2D sketches on different planes, with a single 3D sketch, or with a combination of 2D and 3D sketches. If you have confidence in your ability to use 3D sketches, then that is the best way to go. Three-dimensional sketches can be challeng- ing, but they are certainly manageable if you know what to expect from them. 865 IN THIS CHAPTER Sketching in 3D Using Weldment tools Using non-structural components Using sub-weldments Using Cut lists Creating Weldment drawings Tutorial: Working with weldments Using Weldments 42_080139 ch31.qxp 3/26/07 5:39 PM Page 865 Earlier chapters discuss the tools that are available for 3D sketches; this chapter covers techniques for 3D sketching. Navigating in space When working in a 3D sketch, the cursor and Origin initially look as shown in Figure 31.1. The large red Origin is called the space handle, with the red legs indicating the active sketching plane. Any sketch entities that you draw lie on this plane. The cursor also indicates the plane to which the active sketching plane is parallel. The XY graphic shown in Figure 31.1 does not mean that the sketch is going to be on the XY plane, just parallel to it. FIGURE 31.1 The space handle and the 3D sketch cursor Pressing the Tab key causes the active sketching plane to toggle between XY, YZ, and ZX. The active sketching plane indication does not create any sketch relations; it just lets you know the ori- entation of the sketch entities that are being placed. If you want to create a skew line that is not parallel to any standard plane, you can do this by sketching to available endpoints, vertices, Origins, and so on. If there are not any entities to snap to, then you need to accept the planar placement, turn off the sketch tool, rotate the view, and move one end of the sketch entity. An excellent tool to help you visualize what is happening in a 3D sketch is the Four Viewport view. This divides the screen into four quadrants, displaying the Front, Top, and Right views in addition to the trimetric or isometric view. You can sketch in any of the viewports, and the sketch updates live in all of the viewports simultaneously. This arrangement is shown in Figure 31.2. You can eas- ily access the divided viewport screen by using buttons on the Standard Views toolbar or the view selector in the lower-left corner of the graphics window. You can also manually split the screen by using the splitter bars at the lower-left and upper-right ends of the scroll bar areas around the graphics window. These window elements are also described in Chapter 2. When unconstrained entities in a 3D sketch are moved, they move in the plane of the screen. This can lead to unexpected results when viewing something at an angle, moving it, and then rotating the view, which shows that it has shot off into deep interplanetary space. This is another reason for using the Four Viewport view, which enables you to see what is going on from all points of view at once. 866 Working with Specialized Functionality Part VII 42_080139 ch31.qxp 3/26/07 5:39 PM Page 866 FIGURE 31.2 The Four Viewport view Sketch relations in 3D sketches Sketch relations in 3D sketches are not the same as in 2D sketches. Although vast improvements have been made by the addition of relations such as Midpoint and Equal, other relations are miss- ing, such as Symmetric and Pierce. Pierce is replaced by Coincident, because in 3D sketches, there is no difference between Pierce and Coincident; this is because relations are not projected into a plane the way they are in 2D. The Symmetric relation, however, is sorely missed. On the other hand, several other relations are available in 3D sketches that are not found in 2D sketches, such as AlongX, AlongY, AlongZ, and OnSurface. As mentioned earlier, relations in 3D sketches are not projected like they are in 2D sketches. For example, an entity in a 2D sketch can be made coincident to an entity that is out of plane. This is because to make the relation, the out-of-plane entity is projected into the sketch plane, and the rela- tion is made to the projection. In a 3D sketch, Coincident means Coincident, with no projection. 867 Using Weldments 31 42_080139 ch31.qxp 3/26/07 5:39 PM Page 867 As a general caution, keep in mind that solving sketches in 3D is more difficult than it is in 2D. You will see more situations where sketch relations fail, or flip in the wrong direction. Angle dimensions in particular are notorious in 3D sketches for flipping direction if they change and go across the 180-degree mark. When possible, it is advisable to work with fully defined sketches, and also to be careful (and conservative) with sketch relations. For example, the sketch shown in Figure 31.3 cannot be fully defined without also overdefining the sketch. The main difficulty is that the combination of the tangent arc and the symmetric legs of the end brace cannot be located rotationally, even using the questionable reliability of 3D planes that are discussed next. The only workable answer to this is to create a separate 2D sketch on a real 2D sketch plane, where the plane is defined by the elements of the 3D sketch. If you are interested in examining this part in detail, then you can find it on the CD-ROM. The filename is Chapter 31 – Cant Define.SLDPRT. FIGURE 31.3 Three-dimensional sketches may be difficult to fully define. Planes in space Starting with SolidWorks 2006, it has been possible to create planes directly in 3D sketches. These planes function in some respects like sketch entities, by following sketch relations. Sketches can be created on these planes, and move with the planes. Having planes in the sketch also enables planar sketch entities such as arcs and circles in 3D sketches. This set of sketch entities cannot be located rotationally within the 3D sketch 868 Working with Specialized Functionality Part VII 42_080139 ch31.qxp 3/26/07 5:39 PM Page 868 [...]... is set up properly The PropertyManager for the Mirror feature is shown in Figure 31.26 890 42_0801 39 ch31.qxp 3/26/07 5: 39 PM Page 891 Using Weldments FIGURE 31.25 The model after step 26 FIGURE 31.26 The PropertyManager for the Mirror feature in step 28 891 31 42_0801 39 ch31.qxp Part VII 3/26/07 5: 39 PM Page 892 Working with Specialized Functionality NOTE An easy way to select all of the bodies is... the Extend option is not selected, then trimming is the only action available 877 31 42_0801 39 ch31.qxp Part VII 3/26/07 5: 39 PM Page 878 Working with Specialized Functionality FIGURE 31.11 Using the Trim/Extend feature Trim with planar face Body to be trimmed 878 42_0801 39 ch31.qxp 3/26/07 5: 39 PM Page 8 79 Using Weldments End Cap The End Cap feature closes off an open-ended Structural Member You can... from the Annotations toolbar, click Auto-Balloon The finished drawing looks like Figure 31.28 892 42_0801 39 ch31.qxp 3/26/07 5: 39 PM Page 893 Using Weldments FIGURE 31.28 The finished drawing NOTE Relative views are difficult to create with round pipe rather than rectangular tube, although starting with 2007, planes can be used as references for relative views Summary Weldments are based on either... four lines, you need two Structural Member features 22 Make a second Structural Member feature with the other pair of angled lines The model should now look like Figure 31.24 8 89 31 42_0801 39 ch31.qxp Part VII 3/26/07 5: 39 PM Page 890 Working with Specialized Functionality FIGURE 31.24 The model after step 22 23 Apply another Structural Member feature to the 10-foot (120-inch) section, again using the... weldment Custom profiles are easily created as library features, and you can add custom properties to the library features, and the custom properties then propagate to the Cut lists 893 31 42_0801 39 ch31.qxp 3/26/07 5: 39 PM Page 894 ... should now look like Figure 31.20 Apply an Equal relation to two adjacent sides of the rectangle, and dimension any of the lines as 120 inches 886 42_0801 39 ch31.qxp 3/26/07 5: 39 PM Page 887 Using Weldments FIGURE 31.20 A centered rectangle in a 3D sketch 9 Select one of the lines of the rectangle, Ctrl-select the Top plane, and assign an OnSurface sketch relation 10 Activate the Line sketch tool and press... lines come together AlongX in the positive X direction Dimension this new line as 120 inches The sketch should now look like Figure 31.22 FIGURE 31.22 The sketch after step 16 888 42_0801 39 ch31.qxp 3/26/07 5: 39 PM Page 8 89 Using Weldments 17 Exit the sketch Click the Structural Member toolbar button on the Weldments toolbar In the Standard drop-down list in the Structural Member PropertyManager, select... when a plane violates a sketch relation, the relation is not reported, which severely limits the amount of confidence that you can place in planes that are created in this way 8 69 31 42_0801 39 ch31.qxp Part VII 3/26/07 5: 39 PM Page 870 Working with Specialized Functionality The basic recommendation on this tool is to either use it at your own risk, having been warned, or simply to leave it alone The... Using the Weldment Tools Like the Sheet Metal tools, the Weldment tools in SolidWorks are specialized to enable you to create weldment-specific features in a specialized environment Everything starts from a sketch or set of sketches representing the wireframe of the welded structural members 870 42_0801 39 ch31.qxp 3/26/07 5: 39 PM Page 871 Using Weldments Weldment The Weldment button on the Weldment...42_0801 39 ch31.qxp 3/26/07 5: 39 PM Page 8 69 Using Weldments Unfortunately, there is a lot to watch out for with 3D planes, as they are called The first thing to watch out for is that they do not follow their original definition . confidence that you can place in planes that are created in this way. 8 69 Using Weldments 31 42_0801 39 ch31.qxp 3/26/07 5: 39 PM Page 8 69 The basic recommendation on this tool is to either use it at your. of the part, as shown in Figure 30 .9. FIGURE 30 .9 Adding a sketch for the cut Completed rip 861 Using the Insert Bends Method for Sheet Metal Parts 30 41_0801 39 ch30.qxp 3/26/07 5:38 PM Page 861 7 Insert Bends Method for Sheet Metal Parts 30 41_0801 39 ch30.qxp 3/26/07 5:38 PM Page 863 41_0801 39 ch30.qxp 3/26/07 5:38 PM Page 864 W eldments in SolidWorks are built on driving structural profiles along