I have posted a number of examples of this, but one of the features of Sweep (1 & 2) is the frequent appearance of accordion pleats.
In this illustration I have a three sets of circles at the top. In the middle I have a LOFT using the lower set of circles. At the bottom I have a SWEEP1 using a rail running through the center of each of the circles and the same circles and point used for the center surface.
SWEEP (1&2) would be much more useful if they did not have the tendency to create such accordion pleats.