SolidWorks 2010 Bible

Part II: Building Intelligence into Your Parts

Non-planar sketches become somewhat problematic when you are creating the final extruded fea-

ture. The biggest problem is how you cap the ends. Figure 7.5 shows a non-planar 3D sketch that

is being extruded. Notice that the end faces are, by necessity, not planar, and are capped by an

unpredictable method, probably a simple Fill surface. This is a problem only if your part is going

to use these faces in the end; if it does not, then there may be no issue with using this technique. If

you would like to examine this part, it is included on the CD-ROM as Chapter 7 Extrude 3D

Sketch.sldprt.

FIGURE 7.5

Extruding a non-planar 3D sketch

If you need to have ends with a specific shape, and you still want to extrude from a non-planar 3D

sketch, then you should use an extruded surface feature rather than an extruded solid feature.

One big advantage of using a 3D sketch to extrude from is that you can include profiles on many

different levels, although they must all have the same end condition. Therefore, if you have several

pockets in a plate, you can draw the profile for each pocket at the bottom of the pocket, and

extrude all the profiles Through All, and they will all be cut to different depths.

3D sketches also have an advantage when all the profiles of a single loft or boundary are made in a

single 3D sketch. This enables you to drag the profiles and watch the loft update in real time.

Cross-Reference
Surfacing features are covered in detail in Chapter 27. Chapter 4 contains additional details on extrude end
conditions, thin features, directions, and the From options. Chapter 31 also has more information on 3D
sketches.n