We previously introduced MB & F’s LM Perpetual perpetual calendar movement. For the core reward unit, whether it is an independent brand or high-level complex functions were relatively untouched in the past, so the introduction of the LM Perpetual perpetual calendar movement was also a special example for us; MB & F published LM a month ago The latest work of the series, LM SE, and this new one is actually a simplified version of the LM Perpetual with the unplugged perpetual calendar function. As all the focus in the previous report focused on the complex function mechanism (after all, it is indeed a complicated one that requires detailed explanation Mechanism), the basic wheel of the relative movement can only be passed through in a hurry, and this time the LM SE just removed the complex functions, leaving only the pure basic movement, so we also took this opportunity to look back Analyze the basic structure of this series of movements.
Cal. LM SE
Manually wound movement / eccentric hour, minute, date / power reserve display / 35 stone / frequency 18,000vph / cardless Breguet hairspring, suspended speed-adjusting screw balance, separate escapement system, double spring box
The so-called ‘SE’ refers to the ‘Split Escapement’, which is the split escapement system; the biggest feature of the LM series in the past is the suspension balance wheel drawn from the side of the movement to the surface, and from LM1, 2 to 101, The entire system including the pallet fork and the escape wheel are also moved to the face plate side with the balance wheel, which means that the speed regulation and escapement are on the surface. However, this is not the case for LM Perpetual and SE. It only has a balance wheel on the surface, and the escapement fork and escapement wheel are still on the back of the case, which means that the speed and escapement system is on both sides of the movement. The name ‘Separated Escapement’ was born from this.
According to the official statement, the reason for disassembling the speed control and escapement components is to allow the hanging balance to get a more pure performance; of course, this is also a meaningful incentive, but I believe that the original movement The reason why the design needs to separate the two is because the dial side is equipped with a large number of perpetual calendar mechanisms. The escapement can be placed on the back of the case to make some space-not to mention, the entire surface was previously in LM Perpetual. They are piled with perpetual calendar parts, and the same mechanism does not actually allow the hanging balance to get a more pure performance.
The very long balance wheel shaft must first face the force of twisting when the balance wheel reciprocates, so the movement here strengthens the rigidity of the shaft center at the beginning
The specific structure of the separate escapement will be explained in detail later, but this time MB & F used the same basic movement to disassemble / install complex function modules to develop different products, but it was a little interesting. In the past, the movements of MB & F were almost exclusively for single watches-of course, the similarity of models like HM5, HM8 and HMX is very high, but here we basically treat them as the same time display mechanism Derivative products, in contrast, LM Perpetual and SE are relatively close to the mainstream brand planning products; this point is not meant to refer to MB & F becoming more and more like a mainstream brand. The fact is that when your product volume swells to To a certain extent, this is a very reasonable approach, and here may also show that the so-called independence or the mainstream does not have such a clear line, and strong points are useless.
High rigidity balance shaft
The specific structure of the separate escapement system is to arrange the balance with hairspring on the face plate side, let the axis of the balance wheel pass through the base plate completely, and then install the upstream plate to impact the jewels after coming to the front and back side. Escape wheel. The fundamental difficulty of this structure is that the balance shaft is too long-it has been made much longer than the ordinary balance shaft through the base plate, and the design that lifts the vertical position of the balance wheel makes the final length of the shaft to 11.78. mm; such a long axis must first face the force of torsion when the balance reciprocates, so the movement here strengthens the balance shaft’s rigidity at the beginning to prevent it from twisting and deforming under the transmission of long distance force.
Fine tuning between speed and escapement
Another problem with the ultra-long balance shaft is the accuracy of its balance plate impacting gemstones in contact with the pallet fork, which needs to be adjusted more carefully than usual; turning the movement to the back of the case can be seen in the center Speed control escapement table bridge. At first glance, this bridge is a whole piece, but if you look closely, you will find that there is a disconnection between the balance wheel bearing and the escapement. The relative position between the wheel’s impact gem and the pallet has some room for fine-tuning. It is worth mentioning that shock absorption should also be a major problem for this balance shaft, but from the appearance we can see that it is the general Ingabrero suspension bearing, and what other suspension design is unknown.
Dom-type mirrors are of course to accommodate a hanging balance wheel, but the spherical mirror itself also allows us to enjoy the vertical structure of the three-dimensional balance wheel from the side.
Dual barrel and energy storage display
The balance wheel itself is a large-scale speed-adjusting screw balance with a diameter of up to 14mm, with a Breguet hairspring. Because the large balance wheel is not light and the design of the long shaft is also very torquey, the movement uses a dual barrel with a total energy storage of about 72 hours (of course, this is also related to the original installation of the perpetual calendar module). The two barrels are directly connected by a small coiler, and the independent wheel train in the lower half of the movement is a power reserve display; unlike the impressive three-dimensional energy storage display of the LM1, this is a simple flat pointer form In fact, when the crown turns around in a chain, it takes about 1 hour, and the soft and hard feel is moderate.
Date display and other function configuration
The date display is probably the only function that SE has inherited from the perpetual calendar, and it is also the only date style of the LM series except the perpetual calendar. Judging from the relative positions of the crown, the balance wheel, and the date dial, the date mechanism here should completely inherit the perpetual calendar, and the day-changing method is semi-instantaneous. The entire program is about 23: 50 ～ 00: 00, which is full Short, it can be adjusted quickly by the button on the bottom left. Incidentally, according to the position of the crown, the eccentric hour dial and power reserve display of the SE have moved slightly compared to the perpetual calendar models to match the new surface configuration with greatly simplified functions.
The color of the main surface underneath uses PVD plating instead of transparent enamel. The PVD color film should be thinner, which can highlight the texture of Frosting.
Exquisite hand sanding
One of the great pleasures of enjoying the LM series is to watch the polishing of the movement. This LM SE is definitely worth your careful observation with a high magnifying glass. All the parts have been carefully hand-finished. Do chamfering, and the sharp corner or the gap between the edge of the splint and the curve is the biggest point of manual polishing. Face plate side-I don’t know if it is face plate or the back of the substrate. Rough manual frosting is applied. The surface color is PVD electroplating instead of the transparent enamel used in this price list. The reason is that the color film of PVD is thinner, which can better highlight the texture of Frosting.
Legacy Machine Split Escapement Blue
18K white gold material / manual winding movement / hour, minute, date display / power reserve display / sapphire crystal, transparent bottom cover / waterproof 30 meters / diameter 44mm / limited 18 pieces / reference price: 635,000 RMB
Legacy Machine Split Escapement Grey
18K white gold material / manual winding movement / hour, minute, date display / power reserve display / sapphire crystal, transparent bottom cover / waterproof 30 meters / diameter 44mm / limited 18 pieces / reference price: 635,000 RMB
Legacy Machine Split Escapement Yellow
18K white gold material / manual winding movement / hour, minute, date display / power reserve display / sapphire crystal, transparent bottom cover / water resistance 30 meters / diameter 44mm / limited 18 pieces / reference price: 635,000 RMB