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French Mantle (Slate) Clock Movement


Folkvisor

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Smooth snail wheels are machined in such a way that with each hour the rack drops down a tooth at a time, the only difference is its more difficult to see and judge. With many movements the minute, hour and sub wheels are marked by a small punch mark, have these lined up and all should be correct.

The strike wheels with pins need to be in the correct order. Imagine a clock face and you are looking at it.  The wheel next to the fly should have the warning pin at about 9 45 or 9 50. The gathering pallet wheel with its pin should be resting on the stop leaver inside the movement that is the lever just above the hammer lever. The strike wheel (the one with loads of pins in) should be clear and not in any lifting position of the hammer lever. The gathering pallet should be attached onto the extended pivot at about 10 to the hour (you can always move it if need be) You should have two pins set in the back of the minute wheel, which lift the lever (red arrow) this will lift part (green arrow)The rack will drop down onto the snail, these levers at the time of working also release the wheel next to the fly wheel with the single pin against the guard which is attached to the lever  (red arrow) inside the window (blue arrow). This is called the warning, note the hammer at this stage should not be lifting. When the clock is at the hour, lever (red arrow) will clear the pin on the minute wheel, the guard will also drop causing the strike wheels to rotate. Depending where the rack drops onto the snail will depend how many times it strikes. If there is no punch marks on the wheels, you need to have the rack dropping down for 12 0’clock about here (yellow arrow)   

I know the photo I’m using is for a platform and not a pendulum, the striking is the same.   If you need more info just ask or if you don't understand.

152145213431.jpg

Edited by oldhippy
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23 minutes ago, oldhippy said:

Smooth snail wheels are machined in such a way that with each hour the rack drops down a tooth at a time, the only difference is its more difficult to see and judge. With many movements the minute, hour and sub wheels are marked by a small punch mark, have these lined up and all should be correct.

The strike wheels with pins need to be in the correct order. Imagine a clock face and you are looking at it.  The wheel next to the fly should have the warning pin at about 9 45 or 9 50. The gathering pallet wheel with its pin should be resting on the stop leaver inside the movement that is the lever just above the hammer lever. The strike wheel (the one with loads of pins in) should be clear and not in any lifting position of the hammer lever. The gathering pallet should be attached onto the extended pivot at about 10 to the hour (you can always move it if need be) You should have two pins set in the back of the minute wheel, which lift the lever (red arrow) this will lift part (green arrow)The rack will drop down onto the snail, these levers at the time of working also release the wheel next to the fly wheel with the single pin against the guard which is attached to the lever  (red arrow) inside the window (blue arrow). This is called the warning, note the hammer at this stage should not be lifting. When the clock is at the hour, lever (red arrow) will clear the pin on the minute wheel, the guard will also drop causing the strike wheels to rotate. Depending where the rack drops onto the snail will depend how many times it strikes. If there is no punch marks on the wheels, you need to have the rack dropping down for 12 0’clock about here (yellow arrow)   

I know the photo I’m using is for a platform and not a pendulum, the striking is the same.   If you need more info just ask or if you don't understand.

152145213431.jpg

That's a new one for me I have never seen a smooth snail wheel before. As you say it must be difficult to  get the sequence correct.

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I guess I just lucked out getting to work on a clock with a smooth snail wheel. 

Have you any idea how old such a clock would be? Ballpark...

It is impossible to get this kind of information in books or on the net. If not for this site there would be nothing at all.

You should write a book.

Edited by Folkvisor
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  • 2 weeks later...

Now to regulate it. Providing the springs are good this should keep very good time 1 minute in a week ether way. Once you learn about the striking, these clocks are quite easy to work on. What takes the time is the polishing, cleaning, and bluing screws.

  Happy to help anytime.

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I'm still trying to get it to speed up a little more. small increments. I'm sure I'll be pretty slow when I'm 120 or so years old too.

The pins on the minute wheel aren't any too long so I have to be really careful about pulling off the minute hand or it will pull the pins away from the lifting lever. I'm not sure that I can do anything about that except making sure the pins are in place before I put the clock together.

I'm learning slowly. Someone did a lot of thinking figuring this stuff out!

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Yup. I've found about wheel alignment from experience. There's lots to learn. I'd like to get a French Clock of my own to work on so I can learn more about them.

They want me to fix a grandfather clock but it doesn't look much different than my mantle clock just weights instead of springs and a moon phase 'clock'. Also,  there's lots of info on line about them...unlike French clocks.

 

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Try and get your hands on an 17th or 18th century 8day English Longcase (grandfather) clock. They are wonderful to work on, in my time I must have restored hundreds. French carriage clocks are interesting too, because after all that cleaning, polishing and bluing screws people actually see the clock working, some do have complicated striking.    

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