Dynamic Poising

[Mark]

It's a method devised by Greiner in the late 50's or early 60's which allows the use of the timing machine to find the heavy spot when you have an amount of positional error. I understand that their method rendered the 'static poising' method to be obsolete (their words, not mine).

In the most basic form the method is to test in 8 positions (0 to 7) in the vertical, and find the position where the watch is gaining the most.

The starting position is to draw an imaginary line from the escape wheel centre to the balance centre and set the movement on the microphone with the line vertical, the balance being above the escape wheel. This is position '0'

Each test you turn the movement clockwise by 45º, the first = point 1 second = point 2 and so on.

When you find your heavy spot (where the watch is gaining the most) take the balance off the watch and flip it over so the impulse pin is facing up.

Draw an imaginary line from the staff through the impulse pin to the balance wheel rim. This is point 0. At 45º from this point is point '1' and 90º is point 2. Point 4 is at 180º on the balance rim and hopefully you get the idea.

So whatever position is gaining the most on the timing machine, you would either reduce weight at that point or add weight (timing washer) on the opposite side of the heavy spot. And this depends on the rate when the watch is in the horizontal.

If the watch is slower in the horizontal then you will lighten the screw at the point found.
If the watch is faster in the horizontal then you will lighten the screw opposite the point found.
If the watch is running at zero rate in the horizontal then you would lighten the screw nearest the point found and add weight to the opposite of that point in equal measure to the lightening.

If the balance has no screws then the only choice to be had would be to remove material at the heavy spot, it's not possible to add weight.

Two things to note is that, when testing on the timing machine, the watch should be wound down enough so that the amplitude is between 150º and 180º
And secondly the watch must be cleaned and properly lubricated first.

I hope my overview is clear, it's late and I have enjoyed a few fingers this evening  :) 

[clockboy]

Ok, 

I now have a clear head and here for what its worth is my view and if you read this Mark & I am incorrect please comment. Dynamic poising is for the experienced watch repairer only. The reason I have this view is because out of poise can be caused by many factors. I have read many articles about dynamic poising but before adjusting and going down this route you have to know if it is the hairspring, jewel, balance staff or balance that is causing the out of poise. This really only comes with experience. You can, if not careful adjust the poise via adding weights to the balance but the real problem is actually an out of flat or true hairspring. This is why when I change a balance staff I always check the poise using a poising tool. If there is a subsequent problem I know 100% it is not the balance and in my limited experience nearly always it is the dam hairspring. 

Having said this when I have some time and a scrap watch I will have a play with my watch timing machine and dynamic poising. This is a really interesting subject and a perfectly poised watch will run & run. Finding the reason for the out of poise and correcting would really make a interesting but long video.

[Geo]

Very well explained Mark, it was a lot easier to follow without the wine and port effect. Like Clockboy, I feel an experiment coming on.

I have enjoyed a few fingers this evening  :) 

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[cdjswiss]

Many thanks for the dynamic poising tutorial.

Does this mean that dynamic poising of a balance wheel plus hairspring after, for example, using the timing screws to adjust beat rate without re-poising the bare balance wheel, could result in a dynamic poise where the harspring is compensating a small out-of-poise of the balance wheel itself?

Is this a bad thing - perhaps not?

The joys of watchmaking! The best retirement activity that I can imagine.

Edited December 20, 2014 by cdjswiss

[Mark]

Ok, 

I now have a clear head and here for what its worth is my view and if you read this Mark & I am incorrect please comment. Dynamic poising is for the experienced watch repairer only. The reason I have this view is because out of poise can be caused by many factors. I have read many articles about dynamic poising but before adjusting and going down this route you have to know if it is the hairspring, jewel, balance staff or balance that is causing the out of poise. This really only comes with experience. You can, if not careful adjust the poise via adding weights to the balance but the real problem is actually an out of flat or true hairspring. This is why when I change a balance staff I always check the poise using a poising tool. If there is a subsequent problem I know 100% it is not the balance and in my limited experience nearly always it is the dam hairspring. 

Having said this when I have some time and a scrap watch I will have a play with my watch timing machine and dynamic poising. This is a really interesting subject and a perfectly poised watch will run & run. Finding the reason for the out of poise and correcting would really make a interesting but long video.

 

The problem with poising a balance on a poising tool after fitting a balance staff is, if you make corrections and remove all heavy spots, you could potentially be negating any work done by a previous watchmaker when the watch was manufactured..

Dynamic poising was done by many manufacturers as a measure to compensatate for the breathing of the balance spring. If you then, many years later, poise and correct the balance using a regular poising tool as your measure, then you are negating the work done at the manufacturer and, whilst you may get a perfectly poised balance wheel, in reality when you do final testing, you will be frustrated to find that you still have positional error in the vertical positions.

Enter dynamic poising.

 

Very well explained Mark, it was a lot easier to follow without the wine and port effect. Like Clockboy, I feel an experiment coming on.image.jpg ???????

 

Yes, it's a good idea to play around with the method. I will post some more notes up and some pictures when I get a minute.

 

Many thanks for the daynamic poising tutorial.

Does this mean that dynamic poising of a balance wheel plus hairspring after, for example, using the timing screws to adjust beat rate without re-poising the bare balance wheel, could result in a dynamic poise where the harspring is compensating a small out-of-poise of the balance wheel itself?

Is this a bad thing - perhaps not?

The joys of watchmaking! The best retirement activity that I can imagine.

Many manufacturers adopted this method which, rather than a bad thing, actually is a fast and very accurate way of reducing positional error.

Sadly I was never taught this method when I was an apprentice, I read about it years later and it save me a lot of time and frustration subsequently.

That really is the joy of this trade and learning new things is what keeps the job exciting :)

[autowind]

We live and learn.   :bow: 

[clockboy]

Thanks Mark,

So I have now found out that I might have been doing it wrong. I don,t know what the breathing of the balance spring is and poising is the real deal of watch repairing and I am now getting a bit lost.

I will just have to learn how to dynamic poise. It,s that big learning curve again!!! :startle:  

[bobm12]

Thank you Mark, I enjoyed this explanation and have to admit, it has made some new and useful connections in my brain. I will have, as mentioned before here, to experiment with it a little bit to really get to the bottom of it considering my limited experience. All in all, definitely priority material!

 

Cheers,

 

Bob

[Karimn51]

I have a very basic question for Mark on his dynamic poising tutorial. How much weight do you add or take off? I am confused as what to use as a reference point. Do you take off weight so that it is close to the best time in the vertical position or horizontal position? Sounds like a basic question but I have only done static poising. If anybody else knows the answer please chime in. Thank you fellow horologists.

Karim. USA.

[clockboy]

As I understand it depends on if the watch is running fast or slow whether to add weight on the opposite side of the heavy spot or take weight off the heavy spot. What ever weight it is, it is a very small amount to make the adjustment.

 

I must admit this is one that I really what to try but I just have not had time to play

Edited January 25, 2015 by clockboy

[Watchdog]

Thanks Mark... I think we time in 8 different positions on a timing machine?

So, then I have 8 different readings. With that I've got to figure out my heavy spot. Then mark where I think the spot is..

This really is a "thinking" man's game..

Banking pins,hairspring,dirt,oil and other things could really mess you up.

Yeah, this is advance stuff. I understand the seniors at Litiz's (Rolex) only get 3.5 hours class on this.

With this knowledge it could seperate the men from the boys.. I'm still a little kid,but it sounds fun !!!!

Thanks again. I've learned a lot from the other responces as well.

Thanks all,

[clockboy]

Time is abig issue for me at present. Ie replying to this from Italy. It is advanced watch repair and I will have a go when time. I was told recently that using a poising tool gets it pretty close but the dynamic poising Is more exact

[emso]

I do dynamic poising only on chronometer grade movements,and when i have huge difference of rate than other values

br

emso

p.s: sent from my s****y phone so sorry for typing mistakes

[RandallZadar]

Mark thanks for the information on this. Maybe you can make a video sometime demonstrating the technique. I read somewhere that if the amplitude is under 220, the effect becomes reversed so that a loss becomes a gain. This can be confusing if you are not experienced in this.

 

Randall