When creating sweeps using guide curves, two options appear in the Sweep command to merge faces:Merge Tangent Faces and Merge Smooth Faces. If you’ve ever wondered what these do, well, here is your answer!
Examine the following sweep setup:
We have four sketches to define the sweep: a profile, a path, and two guide curves. When we make our selections and perform the sweep, notice the result with both Merge Tangent Faces and Merge Smooth Faces OFF:
The result of our sweep has a number items that I call “seams,” or divisions between adjacent faces. We see these seams where both guide curves lay as well as well as along the sweep where the guide curves change curvature.
Next, let’s see what happens when we turn ON Merge Tangent Faces:
We get a result that eliminates the seams created by the guide curve positions. Notice we still have seams where the guide curves change curvature. To eliminate those, we’ll turn ON Merge Smooth Faces:
In the end, with both of these smoothing switches enabled, you get one surface that is curvature continuous from end-to-end!
Do note that when you turn on Merge Smooth Faces you will get a warning because SolidWorks is actually changing the surface to be curvature continuous, which means it will be on spline surface. That means relationships to the previous (‘old”) surfaces may very well go dangling, requiring a repair.