Lemania st-19 pressing reset cronograph button

[debian 0]

It is not recommended to press the chronograph reset button while chronograph is running...

But what will actually happen if doing so?

[GC 4,512]

there occurs a rip in the fabric of space & time and another black hole is created...

 

actually it is not a problem because the ST-19 has a column wheel:

 

4.4 What is a Column-Wheel?

As one can imagine, constructing a chronograph is fraught with the potential for inadvertently stopping or damaging the entire movement. For example, if the reset mechanism was somehow activated while the chronograph was running, large destructive forces would be applied to the entire movement train, which would at the very least jam the movement, and would likely destroy several components.

 

The column wheel was one of the successful early designs to ensure that none of the above happened. If you can visualize the top of a castle turret, with tooth-like battlements, this is what a column wheel looks like. The pushers that control the chronograph rotate this wheel, and the various parts of the chronograph are controlled by fingers that fall into and out of the spaces between the teeth. This ensures that each of the chronograph parts is coordinated properly.

 

Because producing and finishing a column wheel is labor-intensive, a simpler, easier method of producing chronographs was needed to keep this complication from appearing only in very expensive watches. The most common method is to use an oscillating pinion to coordinate the chronograph start, stop, and reset (i.e. a cam shaped device that rotates back and forth as the various functions are activated.) This allows for reliable operation without nearly as much fiddling and hand adjustment as a column wheel requires, and the pinion can be built using pieces of stamped metal.

 

These days, relatively few column wheel designs are still being produced - the Zenith El Primero, some Lemania and F. Piguet movements, and (interestingly) a F. Piguet rattrapante mecaquartz are examples. The most common movements, such as the Valjoux 7750 and various Lemania movements (1874, 5100), are not of column wheel design.

 

Walt Odets dissected a Frederick Piguet column wheel chronograph and an oscillating pinion Valjoux 7750 in the Horologium.

4.4.1 Are Column-Wheel chronographs better than other types?

Tough question - much like the question of which watch is the best.

 

Certainly column wheels are a traditional method of coordinating the chronograph components, and tradition counts for a lot.

 

On the other hand, the newer, non-column wheel movements have certainly proved themselves in a variety of demanding situations. Both the column-wheel and non-column-wheel version of the Omega Speedmaster were certified for space flight by NASA. And the non-column-wheel Lemania 5100 has been one of the few mechanical movements to be accepted as sufficiently rugged by modern military forces.

 

So - much like the question of which watch is best, I suggest that one think about which factors are personally most important in a chronograph, and make the decision from there.

[gran 198]

FYI Venus 175 = ST 19 ...it is not a Lemania

[GC 4,512]

FYI Venus 175 = ST 19 ...it is not a Lemania

 

you are correct gran, but all three Venus, Lemania & ST-19 are all column wheel based chronos.

Just so happens that the ST-19 is actually tooled from the old Venus/Lemania machines too.

[debian 0]

Thanks a lot G.Curcio for excellent information :-)

[gran 198]

FYI Venus 175 = ST 19 ...it is not a Lemania

 

you are correct gran, but all three Venus, Lemania & ST-19 are all column wheel based chronos.

Just so happens that the ST-19 is actually tooled from the old Venus/Lemania machines too.

 

 

It is the original Venus 175 machine they bought and propagated .Yes!

 

 

but there is no connection to Lemania what so ever, they are totally different movements..No LEMANIA machines or tools involved at all Lemania is simply wrong...(is my rant getting trough?)

 

happy timekeeping

Gunnar From Venus

[gran 198]

ST19, Venus 175

 

This movement has been around for a long time, but it is still a very popular movement used. We often got asked about this movement. The movement is nearly identical to the Venus 175 as parts are interchangeable. The only differences or improvements to the Venus 175 are the increased beat (the Venus had only 18000 bph vs Seagull’s 21600 vph) and the asians an added incabloc style shock absorber.

 

Technical details: The Seagull 1901 is a 23 jewel, column wheel controlled, chronograph, lever movement operating at 21,600 bph. It has a running second dial at the 9 o'clock position, a 30 minute counter sub-dial at 3 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 column wheel prevents the action of the reset while the chronograph is running.

 

Perhaps the most interesting item in the Venus 175 history is ironically how we came to be the recipients of its clone via Seagull in relatively recent times. Around 1957, a factory in Moscow started producing a copy of an earlier Venus Caliber - the 150. This was the legendary 'Strela' movement. A few years later Venus was planning to reduce the number of movements they offered and were planning to offer an upgrade of the 175 - the 180. But they realized they needed money to do so which they would generate by selling some redundant tooling they didn't need. They first tried to sell it to the Soviets (who had already shown an interest in copying them) but they were happy with the Strela and turned them down. But it just so happened that at the same time the Chinese Airforce was in need of a pilot's chronograph and for political reasons could no longer buy Strela's from the Soviets. So Venus offered them the 175 by selling them all the tooling to make the movements. The early 175 is seen in a Chinese military pilots watches. It was only in production for military purposes for a time and then was eventually released to civilians as the Seagull ST-19 in more modern times.

 

Modern Seagull ST-19:

 

So now you know the not-so-secret- which is that the handwound column wheel chrongraph found in those Chinese watches is actually not a Lemania or a Lemania clone but rather a Venus 175 clone. In fact, one might even make the case that it is a Venus 175 really, since it was manufactered using the original tooling - or at least was at one time. Of course blued screws are laquered and not flame blued and the final finish, decoration, and assembly is how shall we say, "all China", but the function and robustness stand. In fact, many watchmakers have given a sort of seal of approval to the ST-19 as one of the best movements to come out of China. Even the dirty versions seen in some of these cheap watches always seem to hold up well, but if you take the care to have it serviced, there is no reason it couldn't last for many years or even a lifetime.

Edited June 8, 2010 by gran

[debian 0]

The "New Asia Valjoux 7750" does not have a column wheel right?

Does it have some other type of safety devise to prevent you from pressing reset button?

[GC 4,512]

FYI Venus 175 = ST 19 ...it is not a Lemania

 

you are correct gran, but all three Venus, Lemania & ST-19 are all column wheel based chronos.

Just so happens that the ST-19 is actually tooled from the old Venus/Lemania machines too.

 

 

It is the original Venus 175 machine they bought and propagated .Yes!

 

 

but there is no connection to Lemania what so ever, they are totally different movements..No LEMANIA machines or tools involved at all Lemania is simply wrong...(is my rant getting trough?)

 

happy timekeeping

Gunnar From Venus

 

Thank you gran, I truly appreciate the correction, I am always very happy to learn something new!

 

So my apology to the OP: I stand corrected regarding the Lemania movt, albeit I was under the mis-information that the Venus175 and Lemania were one and the same. Updating memory banks as we speak...

[RolexAddict 1]

on the Valjoux/ETA 7750 series and Asian clones, nothing happen - and, mechanically talking, regarding the construction - nothing has to happen if the reset pusher is push when chrono is running.

 

Simple mechanic. No mystic.

Open the case back, play with the pushers, and just observe parts movements, timing etc. Simple.

 

 

[RA's comic mode]

 

Oh ! your $$$ rep is kaput now ? so sorry,

 

well : that's the learning curve, buy another one

 

[/RA's comic mode]

[gran 198]

FYI Venus 175 = ST 19 ...it is not a Lemania

 

you are correct gran, but all three Venus, Lemania & ST-19 are all column wheel based chronos.

Just so happens that the ST-19 is actually tooled from the old Venus/Lemania machines too.

 

 

It is the original Venus 175 machine they bought and propagated .Yes!

 

 

but there is no connection to Lemania what so ever, they are totally different movements..No LEMANIA machines or tools involved at all Lemania is simply wrong...(is my rant getting trough?)

 

happy timekeeping

Gunnar From Venus

 

Thank you gran, I truly appreciate the correction, I am always very happy to learn something new!

 

So my apology to the OP: I stand corrected regarding the Lemania movt, albeit I was under the mis-information that the Venus175 and Lemania were one and the same. Updating memory banks as we speak...

 

Thank you G.Curcio