Chiming & Striking suspended - or stopped?

[oldhippy]

Rixy, I think what he means by being stuck is the hammer didn't drop. 

[Rixy]

Hi OH. I was wondering if he meant that it didn't drop on the third 'hit' (eg at quarter past it played 1 - 2 - no drop) or that it played all the notes but the last one was the third hammer and it didn't drop (1 -2 -3 -no drop). It might be helpful if we can see a video of it.

[dnhb]

15 hours ago, Rixy said:

It's certainly worth a try. When you have the hammers all down, you will see there is a bit of play before the next hammer starts to lift. Try to align the barrel so that it's at a mid-point between the last hammer landing and the next hammer (for the next quarter) lifting.

When you say the third hammer stuck, do you mean it only played 3 out of 4 (or a multiple of 4) notes or that it played 4 notes but that the 4th one was the third hammer?

Thanks: I'll try to find that 'sweet spot'.

I'm afraid I wasn't watching the movement all the time so I can't answer your question, Rixy. I first noticed the 3rd hammer was raised - to the same extent as the 2nd hammer had been previously - a little after the half hour....

[oldhippy]

Sometimes a bit of bur on a tooth that lifts the hammer can cause such a thing or on the part of the hammer that makes contact just be careful as you do not want to file lots away as it will cause loads of trouble, if it is that a little grease try that first. 

[Bod]

On 11/7/2024 at 10:12 PM, Rixy said:

The illustration is from Practical Clock Repairing by Donald de Carle. I'm sure OH is familiar with it, as will many others here. It's quite an old book but explains an awful lot.

You cannot move individual wheels. The whole barrel moves (moving just one would create a new tune - all the right notes but not in the right order!)

I'm not sure how it might have happened unless someone in the past tinkered with it or there is slippage in the system.  Have you checked all the teeth and bushings?

When rotating the barrel observe the movement of the hammers. When you see 'four in a row' (1234) that is the quarter past chime. That way, if you get lost you can roll on and find your way back.

Here is a diagram of the front plate from the same book.

I'd like to thank everyone for mentioning this book, I've gone ahead and got a copy (1981 reprint).

I should have had it years ago, it would have saved a lot of trial and error.  very clear and informative.

 

Bod

[dnhb]

On 11/9/2024 at 11:45 AM, dnhb said:

Thanks: I'll try to find that 'sweet spot'.

I'm afraid I wasn't watching the movement all the time so I can't answer your question, Rixy. I first noticed the 3rd hammer was raised - to the same extent as the 2nd hammer had been previously - a little after the half hour....

 

On 11/9/2024 at 12:40 PM, oldhippy said:

Sometimes a bit of bur on a tooth that lifts the hammer can cause such a thing or on the part of the hammer that makes contact just be careful as you do not want to file lots away as it will cause loads of trouble, if it is that a little grease try that first. 

Thanks both for your suggestions. Returning to this issue after working on other things, I've set the clock up to run outside the case so I can watch it more closely. I now realise that the hammer stuck in a raised position is a symptom rather than the cause: when the clock gets in this state I can get the chime/strike mechanisms to run by gently flicking the Chime side warning wheel governor just after the quarter-hour points when it fails to operate of its own accord. So I now think that the problem is being caused by some excess friction somewhere in the Chime train. I'd previously had a go at cleaning the pivots but will have another go at this & include the leaves/teeth of the wheels: I'm still chary about disassembling the whole movement as I don't feel confident that I will be able to reassemble the mechanisms successfully. The clock does keep good time at the moment & the owner says they'd be quite happy with that if the C/S issue can't be solved.

On 11/7/2024 at 10:12 PM, Rixy said:

The illustration is from Practical Clock Repairing by Donald de Carle. I'm sure OH is familiar with it, as will many others here. It's quite an old book but explains an awful lot.

You cannot move individual wheels. The whole barrel moves (moving just one would create a new tune - all the right notes but not in the right order!)

I'm not sure how it might have happened unless someone in the past tinkered with it or there is slippage in the system.  Have you checked all the teeth and bushings?

When rotating the barrel observe the movement of the hammers. When you see 'four in a row' (1234) that is the quarter past chime. That way, if you get lost you can roll on and find your way back.

Here is a diagram of the front plate from the same book.

I've just ordered a copy - as a Christmas present to myself ! Tthanks again.

[dnhb]

On 12/9/2024 at 11:31 AM, dnhb said:

 

Thanks both for your suggestions. Returning to this issue after working on other things, I've set the clock up to run outside the case so I can watch it more closely. I now realise that the hammer stuck in a raised position is a symptom rather than the cause: when the clock gets in this state I can get the chime/strike mechanisms to run by gently flicking the Chime side warning wheel governor just after the quarter-hour points when it fails to operate of its own accord. So I now think that the problem is being caused by some excess friction somewhere in the Chime train. I'd previously had a go at cleaning the pivots but will have another go at this & include the leaves/teeth of the wheels: I'm still chary about disassembling the whole movement as I don't feel confident that I will be able to reassemble the mechanisms successfully. The clock does keep good time at the moment & the owner says they'd be quite happy with that if the C/S issue can't be solved.

I've just ordered a copy - as a Christmas present to myself ! Tthanks again.

Further to the above, I've found that the Chime (& Strike) mechanism begins to work again when the Chime Spring is wound up again. It seems that when the Spring has unwound by about 4 turns (after about 48 hours) it no longer has enough power to drive the mechanism. I was ready to believe that the root cause of the problem I initially reported was a badly worn pivot hole but would have expected that to have come in to play when the spring was fully wound rather than partially unwound. So this does seem to point to excess friction somewhere in the train....

[Rixy]

Have you checked the chime mainspring? If it has 'set' it has become old and tired, losing its 'springiness'. Be careful how you remove it from the barrel (I recommend a spring winder) and see what the diameter of the released spring is. It should be about 2½ times the diameter of the barrel. If it's much smaller, you may need to replace it.

[oldhippy]

When it comes to replacing clock springs measure the height from inside the barrel to the edge to were the barrel cap fits and the inside diameter, you do not need the strength. If it is not a hook and eye end then you need to mention the fitting you need. Some springs have an end loop.  

[dnhb]

3 hours ago, Rixy said:

Have you checked the chime mainspring? If it has 'set' it has become old and tired, losing its 'springiness'. Be careful how you remove it from the barrel (I recommend a spring winder) and see what the diameter of the released spring is. It should be about 2½ times the diameter of the barrel. If it's much smaller, you may need to replace it.

 

1 hour ago, oldhippy said:

When it comes to replacing clock springs measure the height from inside the barrel to the edge to were the barrel cap fits and the inside diameter, you do not need the strength. If it is not a hook and eye end then you need to mention the fitting you need. Some springs have an end loop.  

Thanks, Chaps. Yes, that's the other side of the coin: if the spring has lost its strength it won't be able to overcome even the inherent friction in the train after a relatively short period. Thanks again for sticking with me on this issue: it's been a good reminder of the Occam's Razor principle!!