Hamilton 21 Stopping

amilevad

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My Hamilton Model 21, purchased October 2021 (it was advertised to have had a complete service prior to the sale) ran continuously and perfectly until now. It just stopped one day although fully wound. After restarting it ran for a day or so, then stopped again. When I opened it up and watched, the escapement seems to work properly, but the balance amplitude just decays until the impulse no longer triggers and it dies. The jewels look good. Does anyone have an idea what’s going on?

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Dick Feldman

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it was advertised to have had a complete service prior to the sale
Your Hamilton clock has a movement made by someone other than Hamilton.
A proper determination of what is wrong cannot be made without the information on the rear plate of the clock movement.
A complete set of detailed pictures of the movement will be most helpful or at least a start.
Have you contacted the seller concerning any warranty?
Best,
Dick Feldman
 

wow

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My Hamilton Model 21, purchased October 2021 (it was advertised to have had a complete service prior to the sale) ran continuously and perfectly until now. It just stopped one day although fully wound. After restarting it ran for a day or so, then stopped again. When I opened it up and watched, the escapement seems to work properly, but the balance amplitude just decays until the impulse no longer triggers and it dies. The jewels look good. Does anyone have an idea what’s going on?
Is this a Hamilton clock with a floating balance?
Photos of the movement would help.
 

amilevad

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Yes, it is a Hamilton movement, model 21. See pictuire attached to original post.
 

TJ Cornish

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My Hamilton Model 21, purchased October 2021 (it was advertised to have had a complete service prior to the sale) ran continuously and perfectly until now. It just stopped one day although fully wound. After restarting it ran for a day or so, then stopped again. When I opened it up and watched, the escapement seems to work properly, but the balance amplitude just decays until the impulse no longer triggers and it dies. The jewels look good. Does anyone have an idea what’s going on?

View attachment 710385
Hello Amilevad- your Hamilton 21 Marine Chronometer is a beautiful piece. This forum actually has a section for chronometers under the watch section - you will likely get more help there.

Generally though, if you are losing power, that means something is binding in the train. This could be as simple as the hands binding on each other, or as complicated as a bent pivot in the middle of the train somewhere, although that’s less likely.

You probably know this, but these watches are EXTREMELY delicate - much more so than the typical watch. Many were retrofitted to have a balance arresting mechanism for transport. If yours doesn’t have that, the balance must be carefully shimmed if you need to ship it. Maybe a moderator can move this thread to the Chronometer section for more help.

Best of luck.
 

DeweyC

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My Hamilton Model 21, purchased October 2021 (it was advertised to have had a complete service prior to the sale) ran continuously and perfectly until now. It just stopped one day although fully wound. After restarting it ran for a day or so, then stopped again. When I opened it up and watched, the escapement seems to work properly, but the balance amplitude just decays until the impulse no longer triggers and it dies. The jewels look good. Does anyone have an idea what’s going on?

View attachment 710385
If it was running well, then it most likely is the trip spring is not long enough to be pulled by the unlocking jewel until the locking jewel on the detent is out of the way of the EW tooth.

This can happen when the depth of the trip spring is just "close enough" to do its job. After a couple months it can wear down just enough to no longer engage the trip spring enough. Or the worker may not have driven the trip spring screw home and the trip spring moved.

The way to check for marginal depth is to hold it vertically (12 up) and then 12 down. Usually the side shake will be enough for the unlocking jewel to engage the trip spring deeper.

The M21 has been a bread and butter for my wife and me for 30 years now. If I told you how many we have serviced (by QB records) you would call me a liar.

To correct the trip spring, the detent block must be removed, detent taken off the block, detent held in such a way so as to not break it while loosening the trip spring screw on the Z bracket.

I bought my last 100 detents from Paul Rye who took home the jigs and tooling from Hamilton. He is now dead and I am told the stuff went to the landfill. I have maybe a dozen left and I now charge quite a bit for a replacement.

I tell you this to help you avoid a very expensive mistake.

If the M21 has my sticker on it, and was serviced in the last 12 months, I honor the warranty, owner is responsible shipping.
 

amilevad

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Thank you both for your comments. Dewey Clark's theory sounds very credible indeed. Unfortunately I have no information about the seller or the person who serviced the device. It there any likelihood that improper or inadequate lubrication could have dried out over the course of the seven months of operation? My supposition under this theory is that the gradually increasing friction of drying bearing surfaces would result in the loss of power that TJ Cornish describes. Would application of a tiny amount of Mobius oil on the exposed jewels be a very stupid way to test this?

BTW, how would I request that this thread be moved to CHRONOMETERS, as TJ suggested?

Thanks again!
 

DeweyC

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If it was a power issue, you would hear the trip spring bouncing back. You would hear a click every 1/4 second; one for trip and one detent hitting the block. It is very easy to look through the plates and see if impulse is being delivered. The EW will move one tooth at a time. You can look either through the detent peep hole in the upper plate or between the plates. If the EW does NOT move, then the trip spring is not long enough.

Could also be the unlocking jewel fell out of the unlocking roller, but highly unlikely.

Also if it IS a power issue, then you are in danger of wiping out the escapement because the EW tooth HAS to be locked on the locking jewel or else the impulse jewel and EW tooth will jam against each other and break pivots, resulting in catastrophic damage when the instrument is wound. This is why you never move hands backwards on a chronometer or interfere in any way with the seconds hand. It is a power stoppage as defined above.

The fact that the balance still rotates argues against the issue just above.

Right now it is a simple issue. Block the balance with a paper wedge, (not cork please) until you get it fixed.
 

gmorse

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Hi amilevad,

I've seen chronometers which ran for about a minute and then stopped, and it was because the mainspring had broken and the movement was kept going on the maintaining power alone. For all their size, these are extremely delicate instruments and should only be serviced by someone who really does understand them.

Regards,

Graham
 

DeweyC

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Here is a brief clip of the movement running. It ran for about a minute. Pardon the background sound if my wall clock, please.
Very useful. The EW is delivering impulse so it is not the trip spring.

I would still recommend blocking the balance and not run it until you get it serviced.

It is curious that it ran fine for 6 months.

As Graham said, the maintaining power can provide power for 5 minutes or more. I have also seen the center wheel or fusee seize, but the instrument was recently serviced. So nothing should be seized. And the maintaining power has to go through the fusee and center wheel. Also, if the mainspring broke, the chain would be loose on the barrel.

But something is interfering with the power.

Other than that , I got nuthin!
 

shutterbug

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I'll move this over to the Chronometer forum for more input.
 
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amilevad

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What is the likelihood of causing problems by applying a small amount of watch oil to the train pivots accessible without removing the dial?
 

gmorse

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Hi Dave,
What is the likelihood of causing problems by applying a small amount of watch oil to the train pivots accessible without removing the dial?
I doubt if you'd do any damage, but I also doubt if it will make any difference to your problem; better to leave it alone until you can take it to a specialist. Do you know how to secure the balance for transport?

Regards,

Graham
 
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DeweyC

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What is the likelihood of causing problems by applying a small amount of watch oil to the train pivots accessible without removing the dial?
Right now you are looking at a basic service charge for an M21. If it self destructs you are looking at over $1000 in parts alone if the entire escapement is wiped out.
 

amilevad

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What should I expect for a “basic service” charge, given that it is already clean and runs as much as it does? I have the balance "corked" with paper darts and the movement is put away for now. Thank you for your help and advice. I'd really like to know what is going on with this thing - to be running well for seven months and then to simply stop running and to only run about a minute on a restart is very weird. Something has either dried out or shifted slightly, or:???:?
 
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DeweyC

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Dave,

If you go to the website in my signature you will find my pricing and direct email. The phone number is pretty useless because cell service is spotty.

Whether I can serve you or you choose someone else, do not run the instrument until it is returned from service. I know this is frustrating, but we all want to help you avoid a total escapement failure.

Regards,

Dewey
 

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