In the late 1950ies, flat watches became popular, and it was neccessiary to construct extra flat movements.
The MST 414 shown here belongs to that class of movements. It was available from 1961 and shows very good rates.
Of course, all important bearings contain rubies, even the minute wheel. For the escape wheel, there’s a KIF Duofix cap jewel on the dial side.
This movement still has a directly driven center minute wheel, which is beared below its own bridge. It’s a bit odd to use this outdated construction for an extra flat movement, while the state-of-the-art construction with a second wheel and indirectly driven hands on the dial side, was already available and allowed even more flat movements. But probably MST wanted to be on the safe side.
We have the classical gear train here with directly driven minute wheel, third wheel, center second wheel and escape wheel.
The three leg Glucydur balance still beats with 18000 A/h. It regulates a conventional swiss pallet lever movement and is beared in two Incabloc shock protection bearings. The exact frequency can be adjusted with an excenter and for mimimizing the beat error, a moveable hairspring stud was used.
This was more or less the best combination available at that time.
On the dial side, you see the yoke winding system. Since the plate is a bit slanted on the outer side, it helps to reduce a little height.
At 9 o’clock, you can see the dial side Incabloc bearing, and around 7 o’clock, there’s the KIF Duofix cap jewel bearing for the escape wheel.
In the lab
The tested specimen was in relatively good condition, but its
surrounding case showed a shock-caused crack, and the center
seconds wheel was broken.
It got a simple service, cleaning and adjustment.
The rates are really good, and it’s likely, that without the damages, it might even run within chronometer specs.
|dial up||+19 s/d||260°||0.4ms|
|dial down||0 s/d||289°||0.0ms|
|crown right (12 up)||-3 s/d||253°||0.6ms|
|crown up (3 up)||0 s/d||248°||0.0ms|
|crown left (6 up)||-9 s/d||232°||0.0ms|
|crown down (9 up)||-9 s/d||235°||0.6ms|
|Number of jewels:||17|
Glucydur screw balance|
|Balance bearing / direction hairspring:||Clockwise|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||3 hole(s)|
|Functions:||hour, minute, second|
|Size:||11 1/2''' (measured: 25,2mm)|
|Production period:||1961 - 1973|
Flume: K2 -|