This is my second favorite Soviet wristwatch movement of the ubiquitous Pobeda.The Luch 2209 has some interesting and arguably pointless design features, but overall, it's accurate & tough. Before I start:
To start the assembly, I've got the mainplate with the set lever/screw and shock spring installed:
The first unusual aspect of the movement is the incredibly small centre wheel and cannon pinion. These are truly tiny pieces..
The keyless works is mostly conventional in its design, except for the set wheels. Most comparable mechanical movements would have just one set wheel, however, this Luch has two. The wheels are the same size, so there is no change in the ratio of input/output, and the physical distance between the clutch and the minute wheel do not seem to warrant the extra wheel (I think it could be achieved with one wheel):
With the bridge installed:
Now for the reverse:
The preference of the Luch 2209's designer for adding superfluous wheels is again demonstrated on the barrel bridge. I think that the ratchet/winding wheel could have been bigger (as it is on most wristwatch movements of this size), and the set of transmission wheels could then subsequently be reduced in number with a slightly larger remaining wheel.
Hidden under the going train bridge, is a smaller bridge that holds two small gears. The only other watch I've seen a similar setup in was Slava from 60's..
The reason for have this small intermediate bridge is to internalize the seconds gearing. In most other watches, the seconds wheel would sit on top of the center wheel and may require another bridge which would also make the movement thicker. This design feature, when coupled with the very small center wheel that I pointed out at the start of the assembly, contribute to a very compact design.
This particular movement belongs in a nice square 10k GP case, so the movement holder is simply a square of aluminum.
These movements are less common that the Pobeda, but definitely more fun to assemble. They are generally a little cheaper than the Pobeda and just look like a quality movement.