Chrono grade Oscilator.

[Nucejoe]

1-  What goes into making a chrono grade oscilator that a regulare oscilators lack? 

2-  Are modern oscilators manufactured on high tech machines and high tech process not as precise as a chrono grades ones? 

3-  What all is superior in a chrono grade movement besides, the oscilator, high precision gears, pinions, arbours and so on? 

4-  Are there different grade of chrono oscilators?  

5-  Are officially certified chrono movements any superior to non certified ones? 

TIA  for any light shed on these questions.

Regs 

Joe

[nickelsilver]

1 hour ago, Nucejoe said:

1-  What goes into making a chrono grade oscilator that a regulare oscilators lack? 

2-  Are modern oscilators manufactured on high tech machines and high tech process not as precise as a chrono grades ones? 

3-  What all is superior in a chrono grade movement besides, the oscilator, high precision gears, pinions, arbours and so on? 

4-  Are there different grade of chrono oscilators?  

5-  Are officially certified chrono movements any superior to non certified ones? 

TIA  for any light shed on these questions.

Regs 

Joe

1- Generally a chrono grade balance will be made from Glucydur, a copper beryllium alloy. It's hard and stable and works well with Nivarox alloy. The hairspring will be Nivarox 1 or equivalent. The jewels will be of extra high quality.

2- The machines used will be the same. But different materials and less control set the pieces apart

3- The main difference is the higher quality materials, as above. On more "boutique" movements, that aren't mass produced, there might be an emphasis on extra finishing of pinion leaves and pivots, perhaps using convex face olive hole jewels, or adding cap jewels to the escape wheel etc.

4- Not really sure, like at ETA? I think they have their top grade, then the other grades.

5- They are superior in that they have been officially tested and proven. It would be like if your neighbor was the best high diver in the world, but had never competed, they can't really claim that title.

Otherwise, from a given manufacturer, I don't think you will see a difference in service life from a chrono grade or a lower one of the same caliber. Going back to the past, something like a Peseux 260 has an enormous mainspring (2.50mm height, 0.13 thick) for the caliber size, driving an enormous balance wheel, with proportionally small pivots, so that piece will probably need more frequent servicing to avoid premature wear from all the power going through the train, and be more delicate due to the tiny pivots.

[Nucejoe]

1 hour ago, nickelsilver said:

1- Generally a chrono grade balance will be made from Glucydur, a copper beryllium alloy. It's hard and stable and works well with Nivarox alloy. The hairspring will be Nivarox 1 or equivalent. The jewels will be of extra high quality.

2- The machines used will be the same. But different materials and less control set the pieces apart

3- The main difference is the higher quality materials, as above. On more "boutique" movements, that aren't mass produced, there might be an emphasis on extra finishing of pinion leaves and pivots, perhaps using convex face olive hole jewels, or adding cap jewels to the escape wheel etc.

4- Not really sure, like at ETA? I think they have their top grade, then the other grades.

5- They are superior in that they have been officially tested and proven. It would be like if your neighbor was the best high diver in the world, but had never competed, they can't really claim that title.

Otherwise, from a given manufacturer, I don't think you will see a difference in service life from a chrono grade or a lower one of the same caliber. Going back to the past, something like a Peseux 260 has an enormous mainspring (2.50mm height, 0.13 thick) for the caliber size, driving an enormous balance wheel, with proportionally small pivots, so that piece will probably need more frequent servicing to avoid premature wear from all the power going through the train, and be more delicate due to the tiny pivots.

Thank you master for taking the time to post answers to all my questions.

Respectfully 

Joe

[Tudor]

I think that sums it up well.

Coming from the "old days" at Omega, they would pick the cream of the crop for "Kew Observatory" testing. The held very tight tolerance on everything, so they had a very low failure rate overall, but like anything made in quantity, there are always some that stand out- particularly regarding positional error.

The old Omega Constellation watches had always held the best of the best movements, and I believe at one time Omega held the highest quantity of Kew certified movements.

Any of them, from the pre-quartz era can be made to perform at that level, but it takes some doing.

[Nucejoe]

19 minutes ago, Tudor said:

Any of them, from the pre-quartz era can be made to perform at that level, but it takes some doing.

Thanks for your response, surely the "some doing" part would be an interesting read, any links, leads ? 

Regs 

Joe

[nickelsilver]

A lot of what makes a watch "chrono" grade is simply the hairspring. I read that sometimes at Mercer they would abandon a given hairspring, sometimes after days (weeks) of adjusting, as it just wouldn't rate correctly. A friend of mine who worked at Hamilton during the war told me one of the bosses in the prototype lab took a rated marine chronometer, and changed the escapement from spring detent to pin lever to demonstrate how fabulous the Hamilton Elinvar Extra hairspring was (mated to their ovalizing balance)- it still rated well within the federal standard for marine chronometers.

 

The fellows I share my workshop with delivered  prototype a while back; this was passed by COSC before delivery as part of the contract. In production the customer couldn't get them to pass... found out they were using another hairspring supplier, suggested they source some Nivarox 1, no, no that's not going to fix it... then, they got Nivarox 1 and boom, it passed.

 

So while you can almost always improve a watch's rate, sometimes no matter what you do you won't get chronometer level performance.

[Tudor]

1 hour ago, Nucejoe said:

Thanks for your response, surely the "some doing" part would be an interesting read, any links, leads ? 

Regs 

Joe

In my watch repair book, there is a section on dealing with positional error. It has a really great chart (I copied it for my work area), which shows "the error", the position, and what to do about it. Also, it reminds us to know when it's "good enough". One take away, without referring to the book I don't have handy, is that for a wrist watch, dial up and pendant down are the two positions of greatest interest. If the wearer has the watch on the right wrist, then pendant up and dial up, with less fiddling with other positions, to reduce hair loss. And from those two positions, their average should be +/-0 to the best of our ability. Then, when worn (or resting on a table), the error will be well within acceptable.

[Nucejoe]

1 hour ago, Tudor said:

In my watch repair book, there is a section on dealing with positional error. It has a really great chart (I copied it for my work area), which shows "the error", the position, and what to do about it. Also, it reminds us to know when it's "good enough". One take away, without referring to the book I don't have handy, is that for a wrist watch, dial up and pendant down are the two positions of greatest interest. If the wearer has the watch on the right wrist, then pendant up and dial up, with less fiddling with other positions, to reduce hair loss. And from those two positions, their average should be +/-0 to the best of our ability. Then, when worn (or resting on a table), the error will be well within acceptable.

 Thank you Tudor, I am sure most of us would find more education on possitional error useful, as its associated with wear mainly on pivots, etc thence inevitable with watch repair.

When rebuilding a chrono balance complete, our choice of hairspring is predetermined and specific to the caliber, the new question now is;  is a chrono balance complete we rebuild as precise as a new but regular factory built one?  

TIA

 

[Tudor]

I would say, if you could get a silicon hairspring, as Omega uses (and I think Oris is using in their latest caliber), you would be hard pressed to improve upon that.

Completely impervious to both magnetic influence and temperature influence (until around absolute zero, where you have other issues). I honestly think that detail is/was a bigger deal than the co-axial escapement, personally.

[jdm]

28 minutes ago, Tudor said:

Completely impervious to both magnetic influence and temperature influence (until around absolute zero, where you have other issues).

Then if it's also resistant to human caused damage, that would make it the greatest thing ever!

[Tudor]

THEN, I would finally be able to work with hairsprings...

[Nucejoe]

1 hour ago, Tudor said:

I would say, if you could get a silicon hairspring, as Omega uses (and I think Oris is using in their latest caliber), you would be hard pressed to improve upon that.

Completely impervious to both magnetic influence and temperature influence (until around absolute zero, where you have other issues). I honestly think that detail is/was a bigger deal than the co-axial escapement, personally.

I am inclined to agree, co-axial is just a smart design, whereas silicone, Nivarox is technology, I read it mostly is kept secret, who knows nano stuff perhaps.

 

[Nucejoe]

1 hour ago, jdm said:

Then if it's also resistant to human caused damage, that would make it the greatest thing ever!

Swiss seem to have bunch of surprises up their sleeve, to show, mechanical is a jewel and quartz is just electronics.

[Tudor]

Not sure how legible this will be, but these are the copies I made from the book (Practical Watch Repairing)

 

[Nucejoe]

On 12/2/2020 at 5:05 AM, Tudor said:

Not sure how legible this will be, but these are the copies I made from the book (Practical Watch Repairing)

 

Thank you Tutor,   I can see that reduction of positional varistions is how you go about building a balance complete for regulation to precision of chrono grade, the more positions adjusted the more precise of a regulation can be achieved.

The charts seem to instruct adjustments for the said reduction and unconcerned about its effect on poise in horizental positions. What did I miss or misunderstood? 

TIA

Joe

[Tudor]

I think that static beat needs to be precise, as well as a good poise of the balance wheel. Of course jewels and pivots in first rate condition, end shake etc.

Then move into this chart, based on the performance you are seeing.

A good take-away for me, is to adjust (on a wrist watch) for best performance (lowest average deviation) with pendant down and dial up. So, I concentrate my efforts in that direction, and unless there is a massive deviation in another position, let them fall where they may.