, laid out in an unusually straightforward manner. Typically they zigzag severely back and forth from the center and back again (in the case of direct center seconds movements) but in the 8810 they make a leisurely traverse between the barrels and the pallets. The reason for this will become apparent shortly.
To the right of the power train (and occupying a good two thirds of the movement) we find the bridge for the barrels and automatic system. The 8810 is a thoroughly integrated automatic design and houses the automatic system, both barrels, the crown wheel and the indirect center seconds pinion under one large bridge. Sandwiching the barrels between the bridge and plate simplifies their responses to torques (either when winding or unwinding) and is sometimes viewed as a sign of a high quality movement. It seems more elegant to me and certainly is attractive in its simplicity. Coupling that with three automatic winding gears under one bridge makes it a little tricky to install properly but not in any undue way. You'll notice that both barrel arbors are jeweled as well as the first two automatic gears (the third one is bushed).
With the rotor removed, I extracted the case screws and clamps and removed the movement from the case, turning it over to address the dial and hands. Through the crystal the dial has a precision and cleanness of design that actually works against it in some way and this effect was only amplified by seeing it unobscured. The thin black printing on the stark white dial gives the dial a bit of a cheap look (possibly the font is the problem), like something you'd expect on a Timex. The nicely applied numerals (they are really quite perfect) offset this impression a little but the elaborately shaped hour and minute hand only further confuse the overall appearance. All I can safely say about the dial is that it is well executed and well captured in photos and beyond that, a matter of taste.
After removing the hands and dial (did I mention very carefully?), we are able to admire the beautifully simple bottom plate. The date numbers are nicely printed on a metal ring, which is secured by two thin bridges, one for the calendar advance mechanism and one for the minute wheel, keyless works and date jumper.
The calendar advance mechanism is very nicely designed and manufactured and provides for an instantaneous date jump with no possibility for damage while quicksetting the date, even between the hours of 9 PM and midnight.
The simplest date change mechanisms employ an impulse finger enmeshing with the teeth of the date ring for a period of several hours. While there are some older movements that have a quickset and no safety mechanism, most modern movements use an impulse finger mounted (or made of) a flexible spring that can slide out of the way if the quickset is activated while it is enmeshed with the date ring. In the Lemania 8810, the date ring remains absolutely stationary until the instant of the date change as I've tried to illustrate in this animation.
The date advance wheel is enmeshed with a transmission wheel that is driven by the hour wheel. It is through this engagement that the date advance wheel is caused to turn at the rate of once every twenty-four hours. A steel pin that is solidly riveted to the date advance wheel protrudes from the underside where it is encircled by one end of a long circular spring. The other end of the spring is fixed to a tube that is free floating on the same arbor as the date advance wheel. The top side of the tube is attached to an impulse finger for the date ring while the underside is attached to a steel disk with a notch in the side to serve as a detent for the instantaneous impulse action. Approximately four or five hours before the time the date is to advance, the notch in the steel disk comes into contact with a straight copper spring that is fixed into the main plate. This detent action causes the steel disk and the impulse finger to remain stationary while the date advance wheel continues its motion. A few moments before midnight a portion of the date advance wheel that is cut and folded downward at an angle comes into contact with a raised portion of the fixed copper spring that is restraining the steel disk and impulse finger.
Precisely at midnight, this folded portion of the date advance wheel frees the fixed copper spring from its detent action with the notch in the steel disk. This allows the steel disk and the impulse finger to flick forward under the action of the long curved spring (which couples them to the date advance wheel) and advance the date ring one position. As a clever solution to the space requirements of the layout of the wheels and pivots, the date advance transmission wheel runs on a large hollow post that has the third wheel jewel at its center. The downside of this arrangement is that the topside of the jewel in question is at the bottom of a deep hole and not easy to inspect for cleanliness.