Radially expanding and contracting table
Some observations: The table top pieces are only truly circular in their larger arrangement. In the “contracted” table, the 6 wedges in fact form a kind of rounded-off hexagon, and the outer table edge is made circular by the rotating rim, which has a complementary inner profile. Besides the wedges, there are two other types of pieces that make up the table top–6 “darts” having two parallel sides that rise to fill the spaces between the wedges, and the “star” (a dodecagram, in fact) that rises up in the middle. The table is locked in either configuration by one or more threaded detents which are quite clearly shown in the upper video.