Fastbeat Vs Slowbeat mechanical Movements.

[padi56]

The high-beat vs low-beat argument has been running as long as I've taken an interest in movements (I am talking about watches here) and opinions are still divided.

One of the more highly regarded chronograph movements is still the Zenith "El Primero" running at 36000 bph. So highly regarded as we all know it was used by Rolex in the Daytona.Now the Zenith calibre 3019 was first introduced in 1969 and I'm pretty sure if there were any problems with hi-beat movements, 42 years is long enough for them to manifest themselves.

Ulysse Nardin marine chronometers have always been highly regarded but it is a little known fact that for years, they were fitted with a high-beat (36000bph) version of the ETA 2824-2, UN calibre NB11QU. Zodiac produced at least four high-beat movements from 1971-73, all with Albert/Shine ebauche, and fitted to the "SST" models. Longines experimented with calibres 430 to 433 from 1967 but when they introduced twin-barrel movements in 1975, chose to revert back to 28800 bph,and in these days Longines made some excellent in-house movements.

Changing the subject slightly, the Longines twin-barrel movements were something I wish had survived in current production,a brilliant movement,but expensive to make. Calibre 890, 892 & 893 had stacked twin barrels whereas calibres 990 to 994 had side-by-side barrels in a movement only 2.95mm thick. The power reserve of 44 hours was respectable but not particularly impressive for a twin-barrel movement, although I'm sure that if R & D had continued on this movement this would have been substantially improved.And would have put many a modern movements to shame,from any manufacturer or brand.

Now the main advantages of slower beat rates (18,000 , 19,800 and 21,600 ) are less immediate. Lower power needs allow for softer mainsprings, limiting stress and friction throughout the wheel train, winding train, and the escapement. Service intervals are longer and more flexible, and part wear replacements are negligible.But in general low beat movements will generally not perform as well as a fast-beat one, and while slow beat movements can perform very well it requires more skill and effort from the watchmaker to achieve and Rolex achieved that though the many years, through laborious positional adjustments and high quality movement parts . Now slow-beat is used primarily by manufactures of high-craft movements, most of whom consider today 21,600 BPH to the best.But most of these type of movements being quite delicate and can easily be put out of adjustment by the slightest Mal adjustment like say a small fall or shock.


Some of the advantages of fast-beat (28,800 v/h and 36,000 v/h) are obvious: better isochronism, and better performance in both vertical and horizontal positions even with minimal adjustment or no adjustment at all.This is one of the reasons fast-beat has been almost universally adopted by mass-producers.If you think of a how fast a quartz movement beats,while Mechanical watch usually have 28000 to 36000 beats per hour, which is 480 to 600 beats per second (Hz), and therefore cannot compete with quartz watches that have around 4000 to 8000 beats per second (10 times faster).So in theory the mechanical High beat movement should be more accurate,with very little difference in over all power reserve, because they use a much stronger main spring.Now some say there is the possible extra wear factor in the Hi beat movement,but IMO as long as the recommend services are done,there is little or no difference.

Now when Rolex's did the modification to the Zenith chronograph, where in addition to reducing the beat rate, they discarded the regulator and installed there own vastly larger Microstella balance wheel,and regulator.And when Zenith would not,or could not, supply the vast quantities Rolex needed, they was forced to design there first ever chrono movement in 2000.

[dddrees]

Great info, thanks Padi.

[BeekerMuppet]

Mechanical watch usually have 28000 to 36000 beats per minute, which is 480 to 600 beats per second (Hz)

Am I reading this wrong? I thought it was 28800/36000 beats per hour = 8/10 beats per second.

[Danand]

That is very interesting thanks!

[frank gama]

I have a 1953 manual wind oyster (cal 710) which is 18000 BPH. Its not COSC but still remains accurate to within 2 seconds a day even after all the years. On the other hand my Blancpain villeret which is 21600 BPH is quite unreliable and can be as much as 12 seconds out in a day. Just goes to show how good Rolex (have always been and) are at making fine movements.

[2th Dr]

Thanks for sharing this Padi! Interesting stuff!

[drlecter]

Great post!

Thanks.

[padi56]

Originally Posted by BeekerMuppet

Am I reading this wrong? I thought it was 28800/36000 beats per hour = 8/10 beats per second.

Thats measurement is in Hertz 480- 600 vibrations per second.

[Frogman4me]

Awesome post Padi thanks for taking the time out to share it with us. cheers

[rolexertion]

Originally Posted by padi56

Mechanical watch usually have 28000 to 36000 beats per hour, which is 480 to 600 beats per second (Hz), and therefore cannot compete with quartz watches that have around 4000 to 8000 beats 10 times faster).

Now when Rolex's did the modification to the Zenith chronograph, where in addition to reducing the beat rate, they discarded the regulator and installed there own vastly larger Microstella balance wheel,and regulator.And when Zenith would not,or could not, supply the vast quantities Rolex needed, they was forced to design there first ever chrono movement in 2000.

Of course mechanical watches beat 28k/36k per hour, not per minute; 4Hz to 5Hz. Most quartz watches 'beat' at 32KHz, 6400/8000 times faster.

The enemy of accuracy is friction, what percentage of the total oscillating momentum is absorbed by friction, and how much that varies with position, dropping spring-tension, temperature changes, etc. A fast-beat movement uses the higher momentum of the faster oscillating mass to better overcome the effects of friction. The same thing can be done with a larger, higher angular-momentum balance. The speed of the 'beat' has little or nothing to do with accuracy per se, it's all in the difference between the angular momentum and the total, variable friction in the train.

A quartz watch maintains high accuracy not because of the fast beat, (32KHz), but because the vibration is not directly connected to the gear train, and thus is unaffected by friction. Instead, an electronic circuit senses the vibration in the quartz crystal, divides it down about 64,000 times, and drives a stepper motor connected to the seconds wheel.

As mechanical watch manufacturers find ways to minimize friction, and to minimize variances in friction, such as with materials that have low friction coefficients without lubrication, mechanical watches will continue to improve in accuracy. They already come very close to standard quartz accuracy, and will probably equal it soon.

[capote]

Edit: double post

[capote]

Thanks for the info

[A.J.R.]

Very informative, thanks!

[padi56]

Originally Posted by rolexertion

Of course mechanical watches beat 28k/36k per hour, not per minute; 4Hz to 5Hz. Most quartz watches 'beat' at 32KHz, 6400/8000 times faster.

The enemy of accuracy is friction, what percentage of the total oscillating momentum is absorbed by friction, and how much that varies with position, dropping spring-tension, temperature changes, etc. A fast-beat movement uses the higher momentum of the faster oscillating mass to better overcome the effects of friction. The same thing can be done with a larger, higher angular-momentum balance. The speed of the 'beat' has little or nothing to do with accuracy per se, it's all in the difference between the angular momentum and the total, variable friction in the train.

A quartz watch maintains high accuracy not because of the fast beat, (32KHz), but because the vibration is not directly connected to the gear train, and thus is unaffected by friction. Instead, an electronic circuit senses the vibration in the quartz crystal, divides it down about 64,000 times, and drives a stepper motor connected to the seconds wheel.

As mechanical watch manufacturers find ways to minimize friction, and to minimize variances in friction, such as with materials that have low friction coefficients without lubrication, mechanical watches will continue to improve in accuracy. They already come very close to standard quartz accuracy, and will probably equal it soon.

Yes typing it quickly got my minutes mixed up with hours but gravity is any mechanical watches worst enemy until they can get over that there will be tiny deviations.They thought that Tourbillons would do just that but IMHO they serve no real purpose in a wrist watch at all,only the fact the watchmaker can make them..Why today there so much admiration for the tourbillon,perhaps the unquestioned and deserved prestige of Breguet, the original inventor.But the tourbillon works best in one position and in theory the tourbillon is always modifying the slight timing errors in the vertical position like say on a static one positon clock.The tourbillon does not correct position variations,as it only prevents them being detected in the usual testing conditions. But when placed on say a vibrograph timing machine, the tourbillon reveals its weaknesses immediately.The tourbillon does not correct anything,in normal wearing wrist movements, it only prevents the detection of an error that still exists in natural gravity with wrist movement.The tourbillon is in fact an additional mechanism that consumes energy without producing anything except misinformation.The energy it consumes is taken from the reserve destined to the regulator. As a result the balance wheel now with less energy will have reduced advantages.Now I agree totally the skill needed to make the cage plus tourbillon etc is a great horological skill.But in reality the watch is no more accurate that several other non tourbillon watches.Gravity is one of the main causes of rate variations in watches. By creating the tourbillon,when Breguet thought he was eliminating its effects,it looks likes to me it was a error on his part,he only masked them like tourbillons do.Now if someone could come up and counteract the effect on gravity on a wrist watch.Now that would be a big break though but until then tourbillon IMO are just good to look at,and they are very expensive,and they make them because they can.

[bondtoys]

Originally Posted by padi56

Zenith calibre 3019 was first introduced in 1969 and I'm pretty sure if there were any problems with hi-beat movements, 42 years is long enough for them to manifest themselves.

The Zenith El Primero movement is well known for having lubrification problems because of the high beat rate.

And high-beat movements have a frequency of 8-10 beats per second, not 480 - 600.

[padi56]

Originally Posted by bondtoys.de

The Zenith El Primero movement is well known for having lubrification problems because of the high beat rate.

Well as long as its serviced at the correct recommend service interval there is no problem.If there was any sort of like you lubrication problems the movement has been around 40 plus years surely Zenith and ETA would have stopped making them years ago.Yes Rolex did reduce the beat rate but only to fall into there own normal 5 year service.Zenith developed a lubrication system based on molybdenum sulphide for there high beat movements.And they experimented first with a 43,200 a/h movement that ran with the oils they had developed without problems.But when launched in 1969 with the 36000BPH movement and yes it had to be serviced with the Zenith recommend oils.Much like George Daniels Co-Axel escapement that needed precise and correct lubrication if it was not done correctly you had problems same for the El-Primo.

[bondtoys]

well, that's what Zenith says.

Independent watchmakers often refer to lubrification problems for the El-Primeros even with the especially developed oils.

[ArcticMoose]

Disregarding the technical aspects, there is one huge advantage to more beats per hour, which is aesthetics. The 28.8k simply looks choppy!

[The Joker]

Thanks Secret for posting. But somehow none of it went in, so please no one test me on the differences.

Damn you hangover.

[Roxas]

Originally Posted by bondtoys.de

The Zenith El Primero movement is well known for having lubrification problems because of the high beat rate.

And high-beat movements have a frequency of 8-10 beats per second, not 480 - 600.

Correct. It's about 480 - 600 beats per minute.

[mrbill2mrbill2]

Originally Posted by bondtoys.de

well, that's what Zenith says.

Independent watchmakers often refer to lubrification problems for the El-Primeros even with the especially developed oils.

I have never heard or read about El Primero lubrication problems. Do you own one and have experienced such? Or is it biased comments?