Part VI: Using Advanced Techniques
For a more detailed look at the primary shape creation tools (Sweep, Loft, Boundary, and Fill) and
surface modeling in general, please refer to the SolidWorks Surfacing and Complex Shape Modeling
Bible (Wiley, 2008).FIGURE 27.4The Boundary Surface PropertyManager
Offset Surface
The Offset Surface has no solid feature counterpart, but it does in 3D what the Offset Sketch func-
tion does in 2D; it may also fail for the same reasons. For example, if you offset a.25-inch radius
arc by.3 inches to the inside, it fails because it cannot be offset up to or past a zero radius. The
same is true of offsetting surfaces. Complex surfaces do not have a constant curvature, but are
more like a spline by having a constantly changing curvature. If the offset is going in the direction
of decreasing radius, and is more than the minimum radius on the face or faces being offset, then
the Offset Surface feature will fail.
One of the ways to troubleshoot a failing Offset Surface is to use the Check tool to check for mini-
mum radius. Remember that the area with the minimum radius is only a problem if the curvature
is in the same direction as the offset. If a small radius will increase when it is offset, then that small
radius is not the problem. The problem comes from the other direction where you are offsetting to
the inside of a small radius.