(Rokicki curx paragraph which may be wrong: "At this point you just insert the larger planets of the two Somsky gears; they are guaranteed to mesh with the sun and the outer planet, so you are done." Really?)
The Somsky construction says I can insert the smaller planet, then the sun, pretty much anywhere in contact with the smaller planet, and still insert the larger planet and gears will mesh---without moving the smaller planet, the outer gear, or the sun, at all. Agreed? If this is true, and if I can get two smaller planets and the sun to mesh with the outer gear fine, then I can insert each larger planet without issue. Remember, I'm ignoring clashing (overlap) of planet gears; I'm only worried about meshing. -- -- http://cube20.org/ -- [Golly link suppressed; ask me why] --