Slava Medical 2428 Review - A cheap entry into high horology concepts and constant force mechanics.

The Slava Medical 2428 is a charming watch with some high horology and affordable values.

0:00 Intro
0:34 Review
20:52 Constant Force discussion

Made in the USSR just 2 years before the fall.
This was the only mechanical pulsometer watch made by the USSR
The story was that doctors and medics helping out with the aftermath of the Chernobyl accident had their quartz watches suddenly run inaccurately or stop due to radiation exposure. Thus a mechanical pulsometer watch was commissioned to the second Moscow watch factory, Slava (Glory).
This particular example was made in April, 1989, 3 years after the accident. It has minimal radiation exposure but still higher than average.

Unique case design nicknamed the fridge case. Made for the healthcare professionals indicated by the Rod of Asclepius logo. Text written in both Latin and Cyrillic. Lollipop seconds hand allowing for easy reading when measuring pulses. A more rare variant called the KFG exists but also lost the red texts design flare.

The movement is the Slava 2428 which has many interesting features.
It runs at 2.5Hz allowing for a very large balance wheel. This gives the movement more ruggedness due to having larging inertial forces and less prone to deviation during bumps.
The power comes from dual main springs arranged in parallel (both barrels discharged simultaneously) giving a more even torque output allowing for a cheap method for constant force. Thus the power reserve was kept at the usual 42 hours, but accuracy was theoretically improved via the parallel dual barrels

Specs:
Diameter: 36.5mm
Lug to Lug: 44.5mm
Thickness: 11mm
Wears like: 43mm
Lug width of 18mm
Acrylic glass
Chrome plated brass construction with SS case back

Constant Force
- The holy grail of watchmaking
- Debated if its considered a complication
- Trying to solve the issue of how a spring's torque changes during its delivery of power
- It is the essence and philosophy behind high horology pursuits
- There are different levels of refinement and complexity to constant force
- innovation can be at any level of the chain (at the origin of the barrel power or at the end point of the escapement)

At the barrel
- Fuse and Chain which was one of the earliest method
- Maltese cross stop works also known as Equal force barrel
- L’instant de vérité (Tensator mainspring)
- Double parallel barrels
- Automatic winding, which is the most common method by keeping it fully wound and thus constant force

Along the gear train
- Special gear teeth - H.Moser teeth, Agenhor teeth (gear w/o play)
- Resonance theory

At the escapement
- Rementoir, and dead beat
- Constant force escapements - Breguet Natural Escapement (Central Impulse)
- New types of escapements: GP, George Daniels, Omega, GS, Misqto, and Desmodromic
- H. Moser double hairspring
- Tourbillon
- Balance wheel material for temperature compensation
- Balance spring material for anti-magnetism

#slavamedical #slava2428 #pulsometer

Тэги:

#slava #TBWS #USSR_watch #Soviet_watch #Russian_watch #Slava_medical #Slava_2428 #Pulsometer #Rod_of_Asclepius #fridge_case #Chernobyl #Cyrillic #KFG_Slava #Dual_barrels #Dual_mainsprings #Double_barrels #Double_mainsprings #Twin_barrels #Twin_mainpsrings #Parallel_mainsprings #Parallel_barrels #Constant_force #High_horology #Fusee_and_Chain #Maltese_cross_stop_works #Equal_force_barrel #Tensator_mainspring #Resonance_watch #Rementoir #Central_Impulse #Natural_escapement

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