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Comment by dadoge | Hacker News Reader

One of the more fascinating aspects of these is how smooth the second hand movement is.

Second hands on Quartz jump once / second. This is to lengthen the battery life.

On mechanical watches, they are smoother than Quartz since the escapement releases power multiple times / sec. But still ever so slightly jumpy since power is still released in discrete increments.

Spring Drive is outta this world smooth…it can do this since battery life is not an issue since it’s mechanically generated power that can be rewound…for practical purposes, it is releasing power continuously, see for yourself here: https://m.youtube.com/watch?v=jcHA5rBQxQc

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It's so funny how the smoothness of the second hand has changed in desirability over time.

It started with mechanical watches that moved relatively smoothly at 3-6 beats per second. Then Quartz came along, and it became fashionable for seconds to move on the second (the "quartz crisis"). Then mechanical watches became fashionable again as quartz watches became commodities during the "Mechanical Renaissance", and it's now a sign of luxury for a "smooth sweeping" second hand again.

And then you have these modern outliers, like the F.P. Journe Tourbillon Souverain, which feature a "remontoire" that stores up energy before releasing it on the second for increased accuracy. So you can pay $250K for a watch that moves like a $10 quartz :)

I hear ya, it does all makes sense tho

Quartz jumping seconds was a novelty back in the day. No one now views it that way, being interested in it was a fad.

Spring Drive now is not a fad, but IMO a sustained niche for enthusiasts. It’s been around a while and has stood the test of time (pun intended!)

The F. P. Journe is high end mechanical art/creativity. Beauty is in the eye of the beholder.

If you’re on a budget and want a deadbeat seconds hand, Jaeger LeCoultre has a deadbeat seconds watch, the Geophysic True Second, which is ‘only’ around $15k :) I believe it has been discontinued and is only available on the secondary market.

https://www.ablogtowatch.com/one-watch-quarantine-pandemic-j...

Actually, at the very high end of luxury watchmaking they prefer lower beat movements as it increases the service interval, exotic escapements like the remontoir are primarily for exhibition purposes/bragging rights.

I never understood the smooth second appeal, my local Ikea store sells clock with a buttery smooth second hand for a few bucks

I had an electromechanical Timex with a dead beat seconds complication. Which means it was a battery powered watch with a balance that was supposed to be ticking 4 times / second and an extra complication added (the dead beat seconds) to make it tick once per second.

If you'd put your ear to it you could hear it tick 3 times in the background and then a loud tock.

I used to be fascinated with that, until I saw a wall clock that had a smooth second hand movement. It was a cheap $10 clock, because it's not an issue to put a larger battery into a wall clock.

Maybe I already got my kick out of seeing a smooth second hand movement and no longer feel the need to look at it on my wrist. Or perhaps my fascination was based on some gatekeeping, and seeing a cheap item with a similar feature made it disappear. Likely both.

I guess people who genuinely admire the engineering effort would be left unaffected.

I wear a mechanical because the loud tick of a full size 1Hz second handdrives me bonkers. Although I can handle the small seconds in a quartz chronograph.

While most quartz watches use cheaper stepping motors, there are also quartz watches which use synchronous motors, so the hands have a perfectly uniform and noiseless rotation movement.

I had some big wall clocks of this kind, and my father had such wrist watches.

The energy consumption of synchronous motors is lower, because they only have to overcome the friction forces, without having to also accelerate the mass of the hands.

I have a clock that is smooth. Bigger batteries help with that, compared to a small wristwatch battery.

A quartz wristwatch with a smooth seconds hand? How long does the battery last?

I am not sure, because that was some years ago, when my father, who used the watch, was still alive, but in any case the battery lasted at least a year.

Yeah, not that I perceive it to be an assumption that is entirely illogical, but why is smooth movement supposed to consume more power? I can understand that jumping less often conserves power but the power hierarchy should be more ticks > less ticks > no ticks, if we ignore potential increased frictions at lower angular velocity as well as challenges of resisting disturbances.

Ticking is achieved with stepper motors. Whatever motor is required to smoothly rotate uses more power.

Synchronous motors are bit like stepless stepper motors.

At large sizes, synchronous motors are much more efficient than stepper motors, so they use much less power.

At small sizes, the synchronous motors must use permanent magnets, which increase their cost and they have windings that are more difficult to make and the difficulty increases with the smallness of the motor.

The electronic drive of a synchronous motor is more expensive, because it must generate sinusoidal currents, not rectangular currents.

At small sizes, a synchronous motor may have a lower torque than a stepper motor , so it might need extra gears, which would increase the cost.

As long as it is still cost-effective to manufacture a synchronous motor, it will always have a better efficiency and a lower power consumption than a stepper motor. The reason why stepper motors are preferred is that at very small sizes they can be much cheaper, especially when including the cost of all associated electronic and mechanical components.

> Second hands on Quartz jump once / second.

Some quartz movements tick more. Grand Seiko 9F has a multi-step tick that is so fast it’s mostly imperceptible. Bulova Accutron too.

> On mechanical watches, they are smoother than Quartz since the escapement releases power multiple times / sec. But still ever so slightly jumpy since power is still released in discrete increments.

Yup, and the higher the beat rate, the "smoother" it looks. Grand Seiko Hi-Beats and Zenith El Primeros come to mind. There's a good Hodinkee article describing the tradeoffs of different beat rates [1].

[1] - https://www.hodinkee.com/articles/watchs-frequency-hz-vph-me...

Yep. Hi Beats are real solid.

GS movements really are massively better than others in the 5-10k price range

Seiko has a 4Hz series of inexpensive quartz movements (VH31) that are at least as smooth as the entry level Seiko NH35. Bulova has a significantly smoother 15Hz quartz movement but you’re going to spend $600 getting it in a watch.

Second hand on Grand Seiko quartz watches moves once per second, but makes two jumps. You can see it in slow motion video, but not with a naked eye.

Very cool, didn’t know that

Bulova Precisionist, a quartz watch with 16 ticks a second, looks very much like spring drive.

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