Help Vintage Elgin Pocket watch running fast

[JohnTosto]

I need help diagnosing old pocket watch that is running too fast

I will try to give as much detail as possible, this is a previously mentioned project WW2 Elgin pocket watch.

Elgin

Prod yr 1943

16s

7 jewel

model 7

grade 291

Ser# 41375491

It was a complete non-runner when I purchased it, I found the following issues.

·        Broken balance shaft pivots

·        Bent Seconds wheel pivot

·        Broken top pivot 3^rd wheel

·        Cracked balance jewel lower.

·        Broken crystal

 

I have a couple of scrappers ser # 30275963, 27820507 & 29280899 all according to the below link share the same parts that I need including balance wheel.

https://pocketwatchdatabase.com/

Still I want to replace shaft, I ordered a balance shaft and my 1^st attempt didn’t go as planned, I did not have a problem with the disassemble but failed at spreading the rivet, not to bore everyone with details but think I used too small of a domed stake, when I lifted the stake after a few taps the wheel and shaft lifted too, use tweezers to pull down……yes you guessed broken lower pivot any way have a couple more on order and think I learn an important lesson.

Again, I do have a good balance wheel from scrapper along with bottom balance jewel, 3^rd & 4^th wheel.

·        Cleaned  bridges, wheels, gears, all parts (parts from scrapper too)

·        Checked balance spring pose

·        Adjusted collet so while balance wheel is at rest pallet fork is in the center of banking pins

·        Reassembled and lubricated  

It runs now, would like to see a little higher amplitude (211), for its age I think beat error is good (0.2ms) however my real concern is the rate is horrible (+781 s/d)

My first thought was contaminates or magnetism of the hairspring but all looks good.

Here are a few pictures of hairspring, balance pivots, banking pins wheel at rest and timegrapher.

 

Any help and suggestions are appreciated.

 

Regards

John

[jdrichard]

You can slow it down by adjusting the timing screws


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[HectorLooi]

Could you take a photo of the regulator, where the hairspring contacts the boot.

[JohnTosto]

Hi Hector,

Here is the picture I believe you asked for.

 

[Nucejoe]

Are you sure you have the right hairsprings on the balance wheel, if not and all else is Ok, let maximum length of hairspring vibrate with the balance, if no change in daily rate, This hairsprings is incompatible with the wheel.

[HectorLooi]

The hairspring looks correct but I think the hairspring stud could be pushed in a little deeper. The overcoil appears to be very low and might be touching the other coils.

Turn the watch edgewise and use a small torch to illuminate the hairspring and watch it 'breathe'. Also check that the hairspring is horizontal.

[rduckwor]

Put the dial and hands on and bench time it for several days.  I find my Chinese timegrapher (W-1000) is terrible with vintage movements.  It will predict a rate of +390 secs or more and yet when I bench time the movement is very accurate.

 

It seems to work fine with modern movements.  Go figure??!!

 

RMD

[jdrichard]

The hairspring looks correct but I think the hairspring stud could be pushed in a little deeper. The overcoil appears to be very low and might be touching the other coils.
Turn the watch edgewise and use a small torch to illuminate the hairspring and watch it 'breathe'. Also check that the hairspring is horizontal.

What is this technique??


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[HectorLooi]

"Zen" hairspring adjustment technique. 

No. I'm saying, watch the hairspring coiling and uncoiling. Make sure that nothing rubs against the hairspring. 

And using a technique that I learnt from you, JD, use the slow motion capture of yr phone camera. The camera can see things that the naked eye can't. 

Like this short video of the watch I was working on last night. Watch the hairspring.... It's so hypnotic.... Zen.... Oooommm....

[JohnTosto]

Hi All

Nucejoe - I believe I have the correct spring, the scrapper I got the hairspring from had same part number based on this website and serial numbers.

https://pocketwatchdatabase.com/

Rduckwor - I tried what you suggested and unfortunately after 12 hrs the watch gained roughly 8 minutes. 

 

Things have changed a little and believe I might be in a better place or maybe worse hoping you can tell me.

My replacement shafts came in and successfully replaced and reassembled balance so watch now has its original balance wheel however now rate is not registering at all, have I just made matter worse and so out of wack its not able to display rate?

I adjusted the regulator for a flat waveform however strangely  noticing at the same interval a set of lines at the top of screen (picture attached), any help as always is greatly appreciated.

 

Regards

 

John

 

 

 

[HectorLooi]

I believe something is touching the hairspring. Could you take a slow motion video of the balance and hairspring in motion?

[Nucejoe]

Hi, Weren't balance wheels produced back then of different weights? jd should know if adjustment for 780secs is doable, it requires plenty of weight also space around the balance wheel. In short was it posed dynamically or static.

[Nucejoe]

Balance wheels made in this era did not all weigh the same, so each balance wheel is to be vibrated with a haisspring. " The scrapper you got this hairspring from" I am afraid may not vibrate with this wheel, since there is a limit to the weight you can add on, therefor, limited adjustment by screws. I am not hands on with Elgines pocket watches, so I don,t know for a fact, but 780secs seem too much to adjust by balance screws. jd knows, he got a truck load of such pieces all of which he has made staff for. If slow motion shows no malfunction on hairspring, considering the amplitude, you just may have a shorter hairspring on the balance wheel. I hope this helps.

[Nucejoe]

Balance wheels made in this era did not all weigh the same, so each balance wheel is to be vibrated with a haisspring. " The scrapper you got this hairspring from" I am afraid may not vibrate with this wheel, since there is a limit to the weight you can add on, therefor, limited adjustment by screws. I am not hands on with Elgines pocket watches, so I don,t know for a fact, but 780secs seem too much to adjust by balance screws. jd knows, he got a truck load of such pieces all of which he has made staff for. If slow motion shows no malfunction on hairspring, considering the amplitude, you just may have a shorter hairspring on the balance wheel. I hope this helps.

[JohnTosto]

 

Thanks everyone for responses and help, Nucejoe thanks for the lesson/education I just assumed same part number (wheel and spring) interchangeable. 

I went back and found original spring and what an improvement!!!! Still have some positional errors going to look into but feel I am much closer to getting this piece working, again thanks and sure I will be asking for help again soon.

Everyone stay safe!

[transporter]

Well done on getting as far as you have, your positional errors may be down to worn jewels, pocket watches are by their very nature and design run in pendant up more than any other position. So other positions may have pivots running on jewels that are slightly out of round .

[Nucejoe]

Getting close means adjust by screws(screws on balance wheel) can now be fruitful. You were right to think both hairsprings have same springness, same "CGS", different length however. I agree with transporter, positional errors are generally due to wear on, jewels also pivots and excess endshake lets different part of pivot come to contact with the jewel hole also in cases there are endstones, pivot end comes to picture as well. I hope this helps.

[Levine98]

Old thread, but really helpful content for me re: have a bunch of old Elgins that I am slowly getting in running order (all grade 291 7j and grade 313 15 jewels). Number one challenge now is getting them to keep time (I've overcome most of the challenges of just getting them ticking). I think in the majority of cases my poor running movements suffer from slight hairspring deformation or in some cases, mis-matched hairsprings to balance wheels. I didn't even know the latter was a concern until I came across this thread.

Edited May 8, 2022 by Levine98

[grsnovi]

3 hours ago, Levine98 said:

I didn't even know the latter was a concern until I came across this thread.

I also discovered that the balance was matched to the main plate s/n.

I have two 313's. One from 1912 the other from 1928 and since they look so similar I thought I could easily swap parts willy-nilly.

Not so.

[JohnR725]

21 hours ago, Levine98 said:

Number one challenge now is getting them to keep time (I've overcome most of the challenges of just getting them ticking). I think in the majority of cases my poor running movements suffer from slight hairspring deformation or in some cases, mis-matched hairsprings to balance wheels. I didn't even know the latter was a concern until I came across this thread.

Usually best on old discussions is to start a new discussion.

Like for instance if you have a watch this giving you a problem you should start a discussion with that watch because I tend to view each watch as an individual watch which means each watch has its own unique problems

A generalization of  people new to watch repair is the failure to grasp the consequences of mixing and matching components. After all you can swap the screws but what about the other stuff and did you notice American pocket watches have serial numbers on all the plates and the balance wheel typically ever wonder why that is?

American pocket watches are made in batches. But even in the batch all the components like the main plates are serial numbered because are manufactured to gather the ability to swap plates is somewhat problematic. The balance wheel is usually serial number to keep that but the pocket watch because it's been adjusted to fit that watch. Specifically the escapement gets adjusted to match the balance wheel looks in their once again problematic if you start swapping you can adjust for the new balance wheel providing understand how to do that.

They hairspring is of the most interesting in that in modern watchmaking and I have a link typically each hairspring is matched exactly to that balance wheel by a process called vibrating. Even though the link shows how they typically do it in school and the factories the machine that does it is really really fast but still each hairspring is matched to that exact balance wheel

http://www.bobinchak.com/watchmaking/2017/4/26/hairspring-week-vibrating-the-hairspring

Now there is some exceptions to the rule? In the case of American pocket watches that have over coil hairsprings or basically any watch with over coil hairspring they hairspring was premade to very exacting specifications. This means that they hairspring will not match the balance wheel causing the balance wheel to have to be matched to the hairspring. So if you look at the ancient pocket watch parts books you would have been able to obtain timing screws to adjust your balance wheel to match your hairspring.

The simplistic of this is if you start mixing and matching hairsprings you're going to have some interesting timing problems?

Then of course there's the other problem the jumping on conclusions that may or may not be correct for the situation? In other words if you're having a timing problem with a pocket watch is it because somebody else swapped they hairspring before you or are you just having a problem because new to watch repair you failed to grasp the fine points of how the balance wheel and hairspring operate. In other words if you don't know what you're looking at you may not see it in may not grasp the problem at all. This is also where having a microscope may not actually help you if you still don't grasp what you're trying to look at.

Then probably the best way to deal with this is start a new discussion with your watch. Give us a background history of where it came from what you've done to it what it's not doing I don't suppose you have a timing machine? Yes there used for more than regulating the watch their used for diagnostics anyone that's trying to repair a watch without a timing machine well does make it a lot more difficult because the timing machine can show us stuff that you can't see otherwise.

Then of course we need some really good pictures of the watch you working on and if you having timing issues good pictures around the balance wheel like looking straight down looking inside ways we need to see what you're not seeing if were going to help you out.