Jewels and VpH

[Teogc]

Lets put fine tuning aside, what is the ideal number of jewels and VpH for a watch to have good precision in timing ?

Thanks in advance..

[taxico]

Lets put fine tuning aside, what is the ideal number of jewels and VpH for a watch to have good precision in timing ?

1 + 2 = 3

the number of jewels have little to do with timing in the short run as their purpose is reduced wear and tear on parts (in the long term). if you want precision, you HAVE to consider beat rate and adjustments.

a higher beat rate, theoretically, allows a watch to recover from a shock (and thus change to timing) faster. a well designed watch, prevents/reduces the impact of such shocks.

unfortunately a higher beat rate wears out parts faster, theoretically resulting in poorer time keeping with age. it seems that 28.8kvph has been/still is the "ideal" compromise.

another factor for accuracy is the power reserve available and escapement (specifically the typical "torque curve" vs "constant force" effect) as the state of a mainspring affects time keeping.

that, or i think i'm not understanding your question or purpose.

[Teogc]

1 + 2 = 3

the number of jewels have little to do with timing in the short run as their purpose is reduced wear and tear on parts (in the long term). if you want precision, you HAVE to consider beat rate and adjustments.

a higher beat rate, theoretically, allows a watch to recover from a shock (and thus change to timing) faster. a well designed watch, prevents/reduces the impact of such shocks.

unfortunately a higher beat rate wears out parts faster, theoretically resulting in poorer time keeping with age. it seems that 28.8kvph has been/still is the "ideal" compromise.

another factor for accuracy is the power reserve available and escapement (specifically the typical "torque curve" vs "constant force" effect) as the state of a mainspring affects time keeping.

that, or i think i'm not understanding your question or purpose.

Thanks for sharing. .

[agong]

Sometimes I just "LOL" at watches with tremendous amount of Jewels. Some have say 80+ Jewels. wahhh! Most of the Jewels in watches now are artificial (synthetic rubies) by the way.

Is it too many? I guess so! With so many jewels, some would be functional where some would be non-functional jewels. Some just decorate its rotor with jewels around its circumference? To us who know what these jewels are for we will find them meaningless. But it appeals to non-watch guys who would be like, "wahhh so many jewels ah? must be expensive!".

Well at least stuffing jewels in watches are still much much cheaper than installing a tourbillon!

[Teogc]

Came across chrono watch of 36,000 VpH, is it normal as to maintain the design accuracy of the watch?

By the way, why some watches have very smooth rotor which able to spin so smoothly with your wrist movement while others don't.
What are the factors contributing to the rotor design?


Thanks

[skydweller_sg]

jewels in a watch are synthetic and has no real monetary value
the value is in terms of reducing friction in the movement (pivot, balance, pallet, escape, third/fourth/center wheels)
without these synthetic rubies, it would be metal rubbing against metal

[taxico]

Came across chrono watch of 36,000 VpH, is it normal as to maintain the design accuracy of the watch?

By the way, why some watches have very smooth rotor which able to spin so smoothly with your wrist movement while others don't.
What are the factors contributing to the rotor design?

i guess it's an zenith EP chrono or vintage watches (GP, longines etc)? it's normal for those to run at 36.6k as they were designed to do so from the outset.

there was a period of time, with the advent of better lubes and the quartz crisis which made a smooth sweep popular, when movement manufacturers were trying to go for as fast a beat rate as possible (> 5hz). eventually this was normalized at 28.8k (the previous "standard" was 18.8k) but zenith retained their fast beat movements.

although zenith was able to do because of reduced wear from a few design/material patents in the el primero, rolex decided to detune the EP to 28.8k when used in their daytonas (4030).

a "smooth" or noisy spin can be attributed to rotor/staff design (jewel/bush/ball bearings and maybe weight), the efficiency/design (including tolerance) of the winding system (eg, 7750 has a single reverser and only winds in 1 direction so it wobbles/spins freely more in the other direction) and wear and tear (eg, unserviced 40 year old rolex whose rotor is rubbing).

[Teogc]

i guess it's an zenith EP chrono or vintage watches (GP, longines etc)? it's normal for those to run at 36.6k as they were designed to do so from the outset.

there was a period of time, with the advent of better lubes and the quartz crisis which made a smooth sweep popular, when movement manufacturers were trying to go for as fast a beat rate as possible (> 5hz). eventually this was normalized at 28.8k (the previous "standard" was 18.8k) but zenith retained their fast beat movements.

although zenith was able to do because of reduced wear from a few design/material patents in the el primero, rolex decided to detune the EP to 28.8k when used in their daytonas (4030).

a "smooth" or noisy spin can be attributed to rotor/staff design (jewel/bush/ball bearings and maybe weight), the efficiency/design (including tolerance) of the winding system (eg, 7750 has a single reverser and only winds in 1 direction so it wobbles/spins freely more in the other direction) and wear and tear (eg, unserviced 40 year old rolex whose rotor is rubbing).

Thanks for sharing..

[Reversing]

Great Info! Thanks