Poising with Collet Attached

[margolisd]

Hi all. In Practical Watch Adjusting, de Carle mentions that "strictly" a balance should be poised with the collet attached. Including the collet stud and a tiny length of HS. I understand that some collets are poised during manufacture and these ones can be identified by their sliced edge. So presumably he's only talking about collets that aren't poised. But I'm wondering how important this is to measure and correct poise. And also, I would guess the rotation of the collet on the balance would make a difference. I'd be interested to know your opinions on this.

[margolisd]

Anyone have any thoughts? Should a balance be poised with the collet attached? Or no need?

[nickelsilver]

It's so impractical to do it makes no sense. If you want better positional rates than poising alone can give then dynamic poising comes in.

[margolisd]

How is it that I've been doing this for over a year now and I've not once heard of dynamic poising! I think it's because I have my nose stuck in very old books! It's revolutionised everything for me. Absolutely brilliant. I'm glad I learnt static poising as it's been good practice. But this has helped so much

[nickelsilver]

Dynamic poising isn't a panacea though. The watch has to be in top shape, and especially the escapement and hairspring in very good condition before doing it. Good to do a static poise first if an old watch or the staff has been changed. That said it really is the best/easiest way to get close positional rates.

[margolisd]

Yeah, that occurred to me. It would make sense to start off with a static poise to get it close then get everything cleaned, oiled, HS flat and true. Check for faults in the train and a million other things. This would certainly be the last step in the process.

[Nucejoe]

Hi margolisd, Static poising is only balancing weight distribution around balance staff.

• Dynamic poising is the bigger picture and aims to ballance distribution of moment of inertia, it includes all mass in rotation/motion and is to compensate for changes in gyration of HS, all at room temperature. Poising stops short of accounting for changes in dynamics of the wheel due to change in the force of gravity.

In short hairsprings  R/R causes change in dynamics of the wheel therefore neccessitates dynamic poising anew.

( Mass distribution of HS changes as the spring winds & unwinds, occures only when the wheel is in rotation thence dealt with in dynamic poising ). Collets split balanced out independently sounds redundant.

The level of sophistication you can buy dynamic poising is offered by high end watches.

In case I havn,t confused you, I can always try by another posting.

 

 

 

 

[Nucejoe]

1 hour ago, margolisd said:

How is it that I've been doing this for over a year now and I've not once heard of dynamic poising! I think it's because I have my nose stuck in very old books! It's revolutionised everything for me. Absolutely brilliant. I'm glad I learnt static poising as it's been good practice. But this has helped so much

Hi marg, as long as your nose isn,t stuck permanently and you get it back unhurt, I,ll be happy to talk watch repair.

[praezis]

1 hour ago, margolisd said:

I think it's because I have my nose stuck in very old books!

Not really, rather in the wrong books. 
Effect of imbalanced balance wheels in different positions is known and published for more than 120 years (Lossier, Saunier, Grossmann etc.)

Frank

Edited January 29, 2019 by praezis

[nickelsilver]

Nucejoe I have to say I don't understand a fraction of what you write but your enthusiasm always tickles me and I enjoy your posts!

[Nucejoe]

Sorry, I didn,t mean to waste fellow forumer,s  time.

What post or point do you wish to start on. Please note I am not a jobber nor have I taken any course in watch design, repair or the like. Just physics.  

A part of my education was in my native language,  therefor shortcoming with terminologies and non native language. Joe

 

 

[Nucejoe]

On 1/27/2019 at 4:18 PM, margolisd said:

Anyone have any thoughts? Should a balance be poised with the collet attached? Or no need?

 

On 1/27/2019 at 4:18 PM, margolisd said:

Anyone have any thoughts? Should a balance be poised with the collet attached? Or no need?

Yes ballance the wheel with roller and HS installed on it. Remoing the stud would improve the result. Hard work for little percision.  

Think in terms of what parts move and at what radius from the stem. No big deal or hard to grasp concept, praezis is right, you just have not read on it, though you common sense would suffice.

[JohnR725]

3 hours ago, Nucejoe said:

Yes ballance the wheel with roller and HS installed on it.

Static poising is the balance wheel only with the roller.

So to help with poising the first link has lots of interesting stuff including Joseph School of Watch Making.  You're looking for unit five which is in the second link an example of poising.

https://www.mybulova.com/vintage-bulova-catalogs

https://www.mybulova.com/sites/default/files/file/Joseph Bulova School of Watch Making - Unit 5.pdf

 

[margolisd]

That's what I thought. But as my original post says, De Carle believed the collet, collet stud and a tiny length of HS  the length of the stud hole should be attached. I was simply trying to understand how much of a difference this would actually make. But now I've discovered the marvels of dynamic poising and this has made me very happy.

[Nucejoe]

Both defintions are stated in observance of laws of physics therefore correct.

So I can poise a wheel with or without HS and correctly call my work static poising.

In the case of poising wihout HS all my work theoretically is down the drain as soon as I install the HS. Yet avoiding destruction of a good HS requires lots of practice if poising with HS installed. 

Lucky we can choose the approach we prefer.

 

 

 

 

[nickelsilver]

You wouldn't ever poise with the whole hairspring, minus stud or with. The hairspring is essentially stationary though sort of winding and unwinding. The collet (and a little bit of the hairspring in the collet) is really rotating with the balance. Even if it was somehow scientifically good to do, how? If a freesprung balance, you still have the little bit that goes in the stud; if with normal regulator, you have what extends from the curb pins to the stud, which can vary greatly. This is why DeCarle said the collet with a tiny piece of spring inside with a pin. That's what counts, and that's why poised collets were made.

Side note- this is also one of the reasons why tiny "ladies" calibers are so difficult to time well, the hairspring collet is always disproportionately large for the size of balance and spring. In theory the spring would attach right at the center of the staff, the farther away the worse things are.

[margolisd]

I'm the new kid here, but what nickelsilver says makes more sense to me. A heavy point on the spring would be in a completely different state on the poising tool compared to being in a watch where it would move and disperse with the coiling and uncoiling of the spring. Hence dynamic posing makes so much sense.

But it's fascinating to discuss and thank you everyone. And that's interesting about ladies calibers. I'm working on one right now for my wife and it's been really tricky.

[JohnR725]

5 hours ago, margolisd said:

But now I've discovered the marvels of dynamic poising and this has made me very happy.

As a reminder dynamic poising is not a substitute for doing a poor job of static poising. Takes a lot of work to statically poise a balance wheel and get it really perfect and thinking dynamic poising will fix the problem isn't really the best solution.

Then the books and passed horological theories? We now can get Chinese timing machines for little over $100 that give us very exacting timing of what the watch is doing The rate amplitude and beat This gives us the ability to see things almost instantaneously the cause and effect. Where the old-school method would be timing over time comparing to something. Watches do a beautiful job of averaging problems over time. So when you're looking at your timing machine and seeing all these defects it doesn't really tell you how the watches going to perform on somebody's wrist for instance that's moving around.

 

[Nucejoe]

JohnR, thank you for sending the links. 

[Nucejoe]

I read the st joseph lesson.shows how to poise. Even says a screw removed, effects the time keeping by a second a day.

As a student in class I would ask. Can,t we adjust at lever ? Is one second in the wheel worth all the trouble of poising?

 

 

[praezis]

4 hours ago, Nucejoe said:

I read the st joseph lesson.shows how to poise. Even says a screw removed, effects the time keeping by a second a day.

As a student in class I would ask. Can,t we adjust at lever ? Is one second in the wheel worth all the trouble of poising?

Maybe you misunderstood. E.g. a pair of 0.02 mm thick washers will change the rate by about 40 s/d. 

@ John: You are not aware that all these nice methods like dynamic poising are based on science and research done before 1900 ?

Frank

[Nucejoe]

 A wheel got mass so is an inertial bady.

Definition of inertia; The tendencey of a mass body to resist change in it's motion.

As the wheel oscillates it's angulare velocity, speed and angulare acceleration  etc undergoe sinusoidal behaviour, becuze the whell speeds up, slows down, stops and returns. So to make complete a cycle and bring about two beats per cycle.

A given  impulse ,  generate a lift angle much depending on the wheels moment of inetia among other factors. Poising is to decrease the tendency of the wheel to resist change in its motion.therefore, poising is to optimize lift angle so to incresase percision not accuracy.

As long as you optimize the lift angle by poising, I can,t care less how you do it.