I found that the threaded shaft piece for the model didn't print well for me, and got stuck when trying to screw in the other pieces, so I designed a threadless version. The diameter of the shaft is designed so that it will fit with the other parts, which still have threads. For me, I found that this piece fit just loosely enough to adjust the pieces with ease, without too much movement being allowed. There are no supports or specific print settings needed for this part, but I recommend using the same settings you use for the rest of the model pieces.
The author remixed this model.
The threadless version of the shaft has roughly the same dimensions as the original piece, but with the threads removed.