How to match balance screws?

[Scouseget]

Hi all.

After several weeks of trying, I'm still plodding away trying to accurately regulate a Waltham pocket watch, one that refuses to behave itself. I've changed and/or added  balance screws in an attempt to resolve this problem but it still runs too fast (I actually think the hairspring is mismatched to the balance wheel but it was supplied from a reputable dealer). Obviously this usually means that I need to add weight, either by adding balance screws, or installing heavier ones in place of some of the existing ones. And therein lies the problem.

I have a little can of left over balance screws from other timepieces, and frankly they all look the same, but obviously they aren't as some of the them will be of fractionally different weights. I hoped my electronic scale would be accurate enough to weight them but 1/10 gram is of insufficient resolution for this this. Given this could someone please let me know his opinion on the following:

1) How does one weigh a balance screw, or failing that, how does one compare weights between balance screws?

2) Are balance screw threads an international standard, or even a national standard? For example, can I expect a balance screw from a Molnija Russian pocket watch to fit in an American pocket watch. Or a Waltham balance screw thread to the same as one from, say, an Elgin?

3) I tried to poise the balance wheel, and it's completely out of balance, even though each balance screw has a seemingly identical looking one directly opposite installed. Would it be best to remove them all and then start from scratch, installing the same total number of screws as were removed?

4) I've tried to source balance screw washers but without avail - any suggestions, or should I not even bother using washers anyway and try some other way of altering the weight of individual balance screws, and if so, how?

Thanks in advance for any help you can give me.

Cheers

[clockboy]

Maybe it is not the hairspring but a cannon pinion issue. If too loose the watch will always run to fast.

 

[Geo]

"1) How does one weigh a balance screw, or failing that, how does one compare weights between balance screws?"

If you know anyone that is a target shooter who loads their own amo, ask to borrow their powder scales.  I still have mine from my shooting days and they will measure to 1/10 of a grain, that's 0.006479891 grams!

Here's a picture of my scales.

 

[oldhippy]

If the balance is completely out, then no matter how many balance screws you add you won’t get far. Start right from the beginning and remove all what you have added. Then start from there by gradually adjusting them, it might just be an adjustment to the original ones. Are you sure the balance is true and not bent. Also make sure the roller is correct and even all round not distorted in any way and impulse jewel is tight in its mounting and no rough edges and is of the correct size. There is also the possibility the hairspring is not compatible with the balance wheel. You could also make sure the staff is correct and not a replacement, check the fittings around the balance wheel and the staff  

I can’t think the treads from Russian pocket watches will fit an American pocket watch balance.

[JohnR725]

14 hours ago, oldhippy said:

If the balance is completely out, then no matter how many balance screws you add you won’t get far. Start right from the beginning and remove all what you have added. Then start from there by gradually adjusting them, it might just be an adjustment to the original ones. Are you sure the balance is true and not bent. Also make sure the roller is correct and even all round not distorted in any way and impulse jewel is tight in its mounting and no rough edges and is of the correct size. There is also the possibility the hairspring is not compatible with the balance wheel. You could also make sure the staff is correct and not a replacement, check the fittings around the balance wheel and the staff  

 

I can’t think the treads from Russian pocket watches will fit an American pocket watch balance.

 

Can we have a picture of the balance wheel plus exactly which Waltham pocket watch do you have?

Why did you get a new hairspring?

Then what is your definition of too fast?

So usually I casually read the question the answers that go back and read for detail. So on the casual reading the message quoted seemed excessive. But reading The question for detail I definitely agree go back to the beginning. The balance wheel absolutely has to be round the arms have to line up. It's really easy to bend bimetallic arms especially when you're adding or removing the weights. You will get some really interesting timing problems if the arms are not where there supposed to be. Then is the hairspring touching anything like the balance bridge? Sometimes it's really hard to tell if it's touching the same with touching the balance arms?

So according to the Waltham Material book there are variations. Usually for American hairsprings they came in several strengths usually referred to as light, medium and heavy or something equivalent. The type whether it's steel or something else depends upon what the balance wheel is made from. Then the strength is determined by the number of screws which you've dramatically changed so something definitely isn't right.

Then I don't suppose you have a timing machine? Not just for timing a watch but problems.

Then as far as screw threads go it's a relatively new thing in watches. The early watches all have different screws all the American companies had their own screw standard sizes.

Then if the balance wheels dramatically out of poise there is no point in timing until you get it poised.

[jdm]

On 10/22/2016 at 9:30 AM, clockboy said:

Maybe it is not the hairspring but a cannon pinion issue. If too loose the watch will always run to fast.

Please explain how exactly a lose/slipping cannon pinion can make a watch run fast?

[jdm]

On 10/22/2016 at 0:45 PM, oldhippy said:

I can’t think the treads from Russian pocket watches will fit an American pocket watch balance.

Why not. Russians started their watch industry buying out an American factory in distress, machinery, unfinished movements, workers and all.

Edited October 23, 2016 by jdm

[oldhippy]

26 minutes ago, jdm said:

Why not. Russians started their watch industry buying out an American factory in distress, machinery, unfinished movements, workers and all.

Because when I was a watchmaker back in the 70's and 80's you could buy packs of screws for American Swiz and Russian watches and screws were not interchangeable, the threads were completely different, a Russian screw tread was co**BLEEP** while Swiz and American had much finer. 

[jdm]

1 minute ago, oldhippy said:

Because when I was a watchmaker back in the 70's and 80's you could buy packs of screws for American Swiz and Russian watches and screws were not interchangeable, the threads were completely different, a Russian screw tread was co**BLEEP** while Swiz and American had much finer. 

Well, the OP asked if balance screws are an "international standard". I don't think that there is "any standard" when it comes to watches. That being said I would be surprised if some Russian balance screws would fit an American balance. The reason is that is a screw so small to not allow much variation in both diameter and pitch.

[JohnR725]

So attached images for Elgin and Waltham tap Screw sizes.

For any of us who have searched through a container screws the word standard in watch repair doesn't really seem to apply.

[Scouseget]

On 10/22/2016 at 3:45 AM, Geo said:

"1) How does one weigh a balance screw, or failing that, how does one compare weights between balance screws?"

If you know anyone that is a target shooter who loads their own amo, ask to borrow their powder scales.  I still have mine from my shooting days and they will measure to 1/10 of a grain, that's 0.006479891 grams!

Here's a picture of my scales.

 

This was a great idea, and as I don't know a hunter, I went to a gun store and bought one of them, very similar to the one shown in your post above. I thought this would work as the resolution is 1/10 grain, and there's 7000 grains to a pound, which is a pretty fine measurement. Alas, it didn't work as hoped as a single balance screw weighs in at just 0.15 grains (well, I actually measured 10 balance screws, which weighed 1.5 grains, then divided the weight by 10). So, insufficient resolution sadly as the least this scale can weight is 0.1 grains - or am I missing something here?

Oh well, onward and upwards. I'll be guided by the suggestions you have all made and I'll keep you posted on the unfolding saga of the Waltham balance problem (oh no, anything but that groans everyone under their breath).

[Geo]

I thought it was worth a try, but had hoped you could have accessed a set of scales without having to purchase them.

[Scouseget]

8 hours ago, Geo said:

I thought it was worth a try, but had hoped you could have accessed a set of scales without having to purchase them.

Actually, I returned the scale at no cost, and then I found an electronic scale on Amazon that measures to 1/1000 gram so have ordered that. It was amazingly cheap ($50) and hopefully this will help once it arrives. 

[JohnR725]

7 hours ago, Scouseget said:

Actually, I returned the scale at no cost, and then I found an electronic scale on Amazon that measures to 1/1000 gram so have ordered that. It was amazingly cheap ($50) and hopefully this will help once it arrives.

So I thought I'd put things in perspective your new scale better but some form of a laboratory scale would be much better. So one milligram (mg) is 1/1000 gram (g) I've attached some images out of the Hamilton deck watch service manual. This is a 35 size watch so it's bigger than the standard pocket watch. So we have a chart that tells you how much weight and the effect on timekeeping. Then another part of the manual showing you the different weights of the various screws. So I am guessing from what I'm seeing you're going to need to be able to measure down to at least .01mg.

Then somewhere in one of my books or somewhere in the universe there is another way to do this. Rather than trying to measure the individual weight of the screws you can make balance. Can't quite visualize it from my memory and not sure which book it was in or where I saw it. But a simple balance to compare one screw to another. That's a be a lot easier than trying to find a laboratory scale to measure the weight to the degree that you need to.

 

[WileyDave]

On ‎10‎/‎23‎/‎2016 at 5:30 PM, jdm said:

Why not. Russians started their watch industry buying out an American factory in distress, machinery, unfinished movements, workers and all.

That was the Dueber Hampden watch Co, http://birthofsovietwatchmaking.blogspot.co.uk/

So yes, some Russian type-1 balance(s)/parts will fit Hampdens and vice/versa, only up to the time that they ran out of original parts, you'd have to compare a true Russian mfg, balance circa  >1930.

p.s Original Hampden balances had movement serial numbers etched on the bottom side. yup it's true!

On ‎10‎/‎22‎/‎2016 at 1:32 AM, Scouseget said:

) Are balance screw threads an international standard, or even a national standard? For example, can I expect a balance screw from a Molnija Russian pocket watch to fit in an American pocket watch. Or a Waltham balance screw thread to the same as one from, say, an Elgin?

I don't think even American PW mfg, Elgin, Hamilton, Waltham or Hampden balance screws are interchangeable. Be interesting to find out, but even I don't have that kind of time on my hands!

[praezis]

Maybe easier than weighing: determine diameter and height, then volume, and multiply with its density (mostly from brass). 

But weight is not all. A high and tall screw has different effect than a low and thick one, both with same weight of course.

Frank 

[digginstony]

I don't think even American PW mfg, Elgin, Hamilton, Waltham or Hampden balance screws are interchangeable. Be interesting to find out, but even I don't have that kind of time on my hands![emoji3]

Elgin aren't interchangeable with Waltham. Walthams Mod 1899 is interchangeable with Mod 1908. Earlier Waltham models are not interchangeable with the two already mentioned. To the best of my memory.

Sent from my SM-G920F using Tapatalk

[oldhippy]

This is all fascinating reading on what you guys come up with about balance screws.

Its turning out to be a good discussion.