Adjusting a broken Hairspring

[jdrichard]

I think the practical way forward is to weight the balance wheel. A word of caution, those weight screws once backed off have a nasty habit of working loose. On better quality b/ wheels have regulating screws which are found on the wheel over the b/ wheel arms. So if there are no further provisions on the wheel to add screws I suggest you start there.
Drill two holes opposite each other over the arms and add screws. If possible "Tap" if not glue. Working over the arms will give a better chance of keeping alignment of the added screws and aid poising.
Also adding washers is good if you can find them. I don't know a supplier but sometimes old stock turn up on flea bay.

Sent from my SM-T585 using Tapatalk

Adding screws seems to be the best option so far. Just need to figure out the best way of adding the screws if there are no holes. Ahhhhhh


Sent from my iPhone using Tapatalk Pro

[jdrichard]

Took some closeups and looks like there could be two holes available in the balance. Which holes are these, timing screw holes?


Sent from my iPhone using Tapatalk Pro

[jdrichard]

Actually, i think there are four holes available. Looks like two on one side on the first pic and therefore there must be another two on the other side. So how much time could i loose with 2 and then with 4 screws. Any math here


Sent from my iPhone using Tapatalk Pro

[clockboy]

Just a thought I presume the canon pinion is Ok & not to loose. If the hairspring has been shortened then the watch will always run too fast. Adding washers, screws to the balance is a bad idea and highly unlikely not to work because the balance will be out of balance.  If the cannon pin is not too loose then (If it was me) just change the hairspring. 

[szbalogh]

6 hours ago, jdrichard said:

Actually, i think there are four holes available. Looks like two on one side on the first pic and therefore there must be another two on the other side. So how much time could i loose with 2 and then with 4 screws. Any math here


Sent from my iPhone using Tapatalk Pro

There are some holes left, great! Add the screws and poise it man!  Poise it after You are in a good rate range!

It looks from here that You will have to reshape the end curve as well.

[matabog]

try with some screws. You got nothing to lose!

[StuartBaker104]

I’m sure I have a book at home with a table to help on screw weights and positions. Should get a chance to look it out tonight.

[digginstony]

In the picture my driver is pointing to the regulator screw which are located over the balance arms and are designed to be moved in or out to adjust timekeeping. Other screws are used to weight the balance and if backed off are more likely to become loose and fall off into the movement.
The micro adjusters on these old watches are not that sensitive as compared to modern "Etachron" assemblies where extreme adjustment can give a variation as much as 10 minutes

Sent from my SM-G920F using Tapatalk

[JohnR725]

1 hour ago, clockboy said:

Adding washers, screws to the balance is a bad idea and highly unlikely not to work because the balance will be out of balance.

They make specific timing washers for use with watches they do not screw up the poise providing you put them on opposite screws. Then American watch companies make or did make timing screws they also do not seem to screw up the poise providing they go on opposite sides of the balance wheel. They been made with enough precision it's not a problem. But if you're going to be playing with replacing screws you probably want to check the poise anyway there is no guarantee that whoever worked on it last actually did that.

[jdrichard]

I’m sure I have a book at home with a table to help on screw weights and positions. Should get a chance to look it out tonight.

Thanks


Sent from my iPhone using Tapatalk Pro

[jdrichard]

They make specific timing washers for use with watches they do not screw up the poise providing you put them on opposite screws. Then American watch companies make or did make timing screws they also do not seem to screw up the poise providing they go on opposite sides of the balance wheel. They been made with enough precision it's not a problem. But if you're going to be playing with replacing screws you probably want to check the poise anyway there is no guarantee that whoever worked on it last actually did that.

It’s now a matter of finding the screws:) i will poise the balance after adding the screws.


Sent from my iPhone using Tapatalk Pro

[clockboy]

I presume moving the balance screws will work the same as the Rolex Microstella screws. These when  moved give an adjustment of +/- 2 secs a day. Trying to get a large adjustment will not work moving the balance screw (in my opinion).

[jdrichard]

I presume moving the balance screws will work the same as the Rolex Microstella screws. These when  moved give an adjustment of +/- 2 secs a day. Trying to get a large adjustment will not work moving the balance screw (in my opinion).

I think, other than trying to find another spring, that adding balance screws is my only option. I can time the balance by counting the half vibes over a second hand and determine if i am in range after i have added the screws.


Sent from my iPhone using Tapatalk Pro

[digginstony]

I presume moving the balance screws will work the same as the Rolex Microstella screws. These when  moved give an adjustment of +/- 2 secs a day. Trying to get a large adjustment will not work moving the balance screw (in my opinion).

I believe the Ops movement has no regulator screws fitted but you're right, making a 12 minute adjustment is going to require screws to weight the balance.
I normally adjust these regulator screws a quarter turn at a time and then wait to see what happens over the coming day.

Sent from my SM-T585 using Tapatalk

[jdrichard]

I believe the Ops movement has no regulator screws fitted but you're right, making a 12 minute adjustment is going to require screws to weight the balance.
I normally adjust these regulator screws a quarter turn at a time and then wait to see what happens over the coming day.

Sent from my SM-T585 using Tapatalk

I will dive in like a child into a pond, not knowing the depth but having the excitement of the dive alone in mind.


Sent from my iPhone using Tapatalk Pro

[JohnR725]

The Rolex timing screws have a very tiny amounts of adjustments because they are so close they don't need a lot of adjustments. Older watches larger balance wheels the mass of the screws a variety of other things the adjustments are different. For a clue I'm attaching something from Hamilton watch company. Meantime screws nice chart showing the effect of turning these. Then the threads on the meantime screws are different than regular screws to allow them to be adjusted but lots of adjustment they will become loose with time.

Then I'm attaching an image of your own balance wheel you do have two meantime screws which will give you a tiny bit of adjustment.

Then you will note at the bottom of the chart Hamilton comments about using timing washers. The only problem with timing washers are they are really tiny and the maximum per pair is three minutes per day. Then you can use more than one pair but usually in the assortments that you find on eBay for instance all the larger sizes are gone.

Timing screws at least for American pocket watches were available. Compared to a timing washer they add a lot of time to the balance wheel image attached from Elgin watch company. Notice the timing is seconds per hour versus per day.

To give you an idea of physically the size of the screws are looking for an experiment remove one pair of screws. As a reminder everything you do with the balance wheel has to be on both sides to keep it poised In other words both sides the balance wheel have to be the same. So see how much faster the watch runs with two screws missing it should be quite dramatic the screws look to be rather large in size. I suspect you going to need really small screws compared to what you have.

 

[StuartBaker104]

I dug the book out, but note that you have pasted a picture from another page above. The chart didn’t tell me what I had remembered it did (common problem!). It’s on pages 136/137 and it does explain that the open holes are there to allow you to move screws to compensate for temperature errors, not for timing. Are there holes over the balance arms as you could add weight there without impacting thermal compensation?

Timing washers seem to be hard to come by, but Timesavers has some.

[digginstony]

As John stated removing screws will have a dramatic effect, so will adding them. It's going to be a matter of trial and error and moving screws around, equally. But the more central away from the balance arm the less effect.Screws with a head of reduced depth would be a good starting point or reducing the depth of head size as required. A solution is really going to depend on what's available for these old watches and what's required of them. My pocket watches live in a display case, so my concentration of timekeeping is going to be in the crown up position. Positional error is more a consideration if the watch is used in every day life. It's just a pleasure to keep these oldtimers ticking

Sent from my SM-G920F using Tapatalk

[jdrichard]

As John stated removing screws will have a dramatic effect, so will adding them. It's going to be a matter of trial and error and moving screws around, equally. But the more central away from the balance arm the less effect.Screws with a head of reduced depth would be a good starting point or reducing the depth of head size as required. A solution is really going to depend on what's available for these old watches and what's required of them. My pocket watches live in a display case, so my concentration of timekeeping is going to be in the crown up position. Positional error is more a consideration if the watch is used in every day life. It's just a pleasure to keep these oldtimers ticking

Sent from my SM-G920F using Tapatalk

I think i will start by adding two screws and measure the effect by timing the balance in a way similar to the article i attached. This is a british watch, so the screws may be metric thread???


Sent from my iPhone using Tapatalk Pro

[rodabod]

Unlikely metric if British. Just use what fits. Even Swiss watches are not necessarily consistent in balance screw threading.

I've done something similar to you for an IWC Cal 83 which was using a later Cal 89 hairspring. It was +600s per day, and I added extra screws and balance washer to get in range. Finally poised with smaller washers.

As this is a bi-metallic temperature compensated balance, you may want to keep the added weight towards the arms of the balance, where the quarter screws would often be. I'm interested that you appear to have adjustable screws on this balance....

[jdrichard]

Unlikely metric if British. Just use what fits. Even Swiss watches are not necessarily consistent in balance screw threading.
I've done something similar to you for an IWC Cal 83 which was using a later Cal 89 hairspring. It was +600s per day, and I added extra screws and balance washer to get in range. Finally poised with smaller washers.
As this is a bi-metallic temperature compensated balance, you may want to keep the added weight towards the arms of the balance, where the quarter screws would often be. I'm interested that you appear to have adjustable screws on this balance....

Good to see that someone else has tried this out. Other than adding washers, there is not a lot of material (in my numerous books) on adding balance screws to solve this problem. They all assume the spring length is correct to begin with.


Sent from my iPhone using Tapatalk Pro

[Watchfixr]

Timing washers are available from Jules Borel and possibly other suppliers. However, they are rather expensive for just tinkering around. To preserve the poise, four washers selected to correct the error should be added to the balance at 90 degree points on the wheel. Using only two will make it more difficult to poise the balance. In all probability, the error is too great to be corrected by the addition of washers.

Regarding the meantime screws, they are set when the balance is vibrated initially at the factory. I, for one, leave them alone. They are a friction thread and will almost certainly loosen when adjustments are attempted. Once loose, they will never stay in place again.

I would try to get a suitable hairspring and go from there. Ofrei in California has some hairsprings although I don't know if they have any large enough and strong enough for a balance that size. Sometimes they crop up on eBay. Be warned, installing a new hairspring can be tedious work.

[jdrichard]

Timing washers are available from Jules Borel and possibly other suppliers. However, they are rather expensive for just tinkering around. To preserve the poise, four washers selected to correct the error should be added to the balance at 90 degree points on the wheel. Using only two will make it more difficult to poise the balance. In all probability, the error is too great to be corrected by the addition of washers.
Regarding the meantime screws, they are set when the balance is vibrated initially at the factory. I, for one, leave them alone. They are a friction thread and will almost certainly loosen when adjustments are attempted. Once loose, they will never stay in place again.
I would try to get a suitable hairspring and go from there. Ofrei in California has some hairsprings although I don't know if they have any large enough and strong enough for a balance that size. Sometimes they crop up on eBay. Be warned, installing a new hairspring can be tedious work.

Thank for the advice. I may try adding screws first to see the effect.


Sent from my iPhone using Tapatalk Pro

[StuartBaker104]

You could try adding a couple of blobs of rodico to trial the effect

[jdrichard]

You could try adding a couple of blobs of rodico to trial the effect

That is a really interesting option. I am getting a jewellers scale in a few days and i could weigh out the equivalent of a screw. Would need to add it to the existing empty space for screws so that the distance from the center of the balance is the same, else the math will not work. I am off on business so this approach could be taken this weekend. I am also expecting some timing screws soon.


Sent from my iPhone using Tapatalk Pro