The 31681 MakTime is a 25 jewel, cam controlled, chronograph, coulisse lever system movement operating at 3 Hz (21,600 vph). It has a running second dial at the 9 o’clock position, a 30 minute counter sub-dial at 3 o’clock, a 24h sub dial at 6 o’clock, and a sweep second counter mounted centrally along with the timekeeping minute and hour hands. The chronograph functions are controlled through two buttons, one (at 2 o’clock) for starting and stopping the chronograph, one (at 4 o’clock) for resetting the second and minute counters. The cam prevents the action of the reset while the chronograph is running. The 31681 has a datering and a date quickset mechanism, it can be used by turning back the hands to 23:00 and advancing them to midnight and back again to advance in days.
|Movement Calibre:||31 mm|
|Movement height:||7,38 mm|
|Functions:||hours, minutes, seconds, calendar, summing up stopwatch, 24-h scale|
|Frequency:||3 Hz (21.600 vph)|
|Daily rate:||from -10 to +40 s/day|
|Power reserve:||Chronograph off: 42 h|
Chronograph on: 37 h
In the 1970s, the swiss movement factory Valjoux (a short form for Vallée de Joux) sold their machinery that once produced the chronograph caliber 7734 to the USSR. The watch factory Poljot then used this machinery to produce the 31mm chronograph movement 3168. Most of the parts of the Poljot 31681 are identical to the Valjoux 7734.
Different from the ETA-Valjoux 7734 movement, all chronograph related gears run in jewels, and the Glucydur balance swings in a shock protection system that was developed by Poljot. The balance was modified to a smaller diameter what makes the 3133 faster beating at 3 Hz (21,600 vph). compared to the 7734 with 2.5 HZ (18.000 vph).
The Russian 31mm caliber movements renowned for being robust, precise and reliable. These movements are real workhorses! The 31681 MakTime is no exception.