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French clock problem

BOBJAYR

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Mar 12, 2009
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Have a french clock, see photos, that i am having difficulty with.

I have several times reset the snail so that the rack tail properly
falls on the snail to properly give the proper hour. I then have
checked it thru out the hours and making sure that the 12 and 1
properly strike since these are most times the critical hours.

After a couple of days, the clock stops and i find that the rack
tail is stuck against the snail. The clock apparently struck 12
correctly but it hit too close to the angle between 12 and 1
and becomes stuck when it tries to retract.

I have then reset the snail several times only to have the clock
consistently stop as mentioned above.

The snail, the hour wheel and the minute wheels all seem to have
a lot of play or slack when i move them manually.

Is this the problem that the wheels including the snail have too
much play and over time they move and create the above problem?

Or are there other issues that is causing my problem?
DSC00042.jpg DSC00043.jpg DSC00045.jpg DSC00046.jpg
i would appreciate any help anyone can give me in analyzing and
resolving this problem.

Thanks, bob
 

Willie X

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Feb 9, 2008
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The strike train may be stalling. This can be caused by many things but the two most likely culprits are, a stickey mainspring, and/or the hammer is lifting on the warning.
For the snail to actually shift would be unusual. If this is the case something would have to be amis somewhere in the motion works.
Willie X
 

Ralph B

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Nov 25, 2006
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I'd agree with Willie.

The times I have had this happen have been when the customer decided not to wind the strike as they didn't want striking.
Obviously not the case here but sounds like a fault in the strike chain.
At least you've escaped what usually happens next when customers do this, they force the hands around and tear out a tooth.
 

Eckytock

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Feb 24, 2012
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On reassembly did you align the three dot/punch marks on the cannon pinion, minute and hour wheels?
 

harold bain

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When you find it stopped like this, what time is it showing? If you wind it up first, then back up the minute hand, will it strike and clear the problem?
 

R&A

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Oct 21, 2008
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Check the pin that the rack is on. It may have gotten bent to the left to far and you may have to adjust it to the right.The angle of the lift maybe hitting the side of the snail on the lift. How warn is the center shaft bushing? This may cause the problem.
 

BOBJAYR

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Thanks to all for your suggestions. I'm going to check out
each of your suggestions and see if I can get this corrected.

Bob
 

R&A

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Let us know. The results will be in.
 

BOBJAYR

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I need to check this. I did not make sure the three dots on the cannon pinion, minute and hour
wheels were aligned. Could this be my problem.

Thanks, bob
 

Talyinka

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May 14, 2011
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This sometimes happens if the rack bushing is too worn. What happens is that when you install the rack you seat it all the way down on the pin holding it - after a while it works its way slightly "upwards" causing too much play. I remember first time I came across this years ago. It took me ages to figure out what caused it. It is easy enough to remedy - you just make a new rack bushing out of a suitable length of brass tubing, solder it in and ream it to the correct cone dimensions. This type of wear is actually quite common on these movements.
 

shimmystep

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Mar 5, 2012
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I have several times reset the snail so that the rack tail properly
falls on the snail to properly give the proper hour.....

After a couple of days, the clock stops and i find that the rack
tail is stuck against the snail. The clock apparently struck 12
correctly but it hit too close to the angle between 12 and 1
and becomes stuck when it tries to retract.

I have then reset the snail several times only to have the clock
consistently stop as mentioned above.
When you say 'reset the snail'. Can you explain what you mean by 'reset' ?

I'm a little confused where you say the 'clock apparently struck 12 correctly but it hit too close to the angle between 12 and 1 and becomes stuck when it tries to retract'

It can't have struck correctly AND got stuck, no? or am I misunderstanding :)

Do you mean the rack tail dropped correctly but then got stuck against the 12-1 drop off? Without being the teeth being gathered up?

As mentioned, you can check for dots on the wheels but often there are none. Also they are not 100% correct sometimes!
 
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Eckytock

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May be worth lining up those dots. They can just be seen in your first photo except for the dot on the cannon pinion which is hidden behind the snail.
French Movement Dot Alignments.jpg
I found this diagram on this site showing the markers.
 

BOBJAYR

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Thanks for your reply. Just lined up the three dots and got it in test now.

I'll see if that was my problem.

Thanks, Bob
 

BOBJAYR

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Aligned the 3 dots twice and did not help. Clock stopped consistently twice
after couple of days. The tail of the rack again stopping after striking 12
against the side of the snail.

I am now thinking that my cannon pinion is loose and not snug. I can rotate
it slightly back and forth without moving the arbor.

Should it not be snug but not so tight that you cannot move the hands to set
the correct time.

I'm thinking I need to slightly crimp the cannon pinion to snug it.

I'm now guessing that after some time the cannon pinion is slipping just enough
to allow the snail to slightly move from its correct alignment.

What do you think?

Thanks again for your help, Bob
 

Fitzclan

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Jul 20, 2014
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Hi Bob,
One more thought; (make that two), If you watch the strike hammer, at the end of the strike sequence, is the hammer completely at rest, or does it lift somewhat after the final strike?
If you see that it lifts after the last strike, there is another adjustment that can be made without separating the plates. If this adjustment is not made, it may cause the clock to stall.
There is a cock on the rear plate that is the pivot for the pinwheel.
FIRST let-down the springs, then remove the cock.
There is a punch mark on the pin wheel that must be lined up with a specific leaf on the pinion of the gathering pallet. This leaf is ground at a 45 degree angle on the top of the leaf.
With the cock removed, it is possible to re-position the wheels so that the punch mark and the ground leaf mesh. Once this is done,the hammer will come completely to rest at the end of the strike sequence releasing any stress caused by lifting on the time train.
The second thought, which should precede the previous setting, is the warning pin setting. It is somewhat different on count wheel clocks (which should be set between 6 and 8 o'clock).
On rack & snail, the pin should be set about 1/2 a revolution away from the warning lever which is at about 11 o'clock.
The punch marks on these movements are critical to the proper operation of these clocks. They are there for a reason and if properly set up will dissolve a host of issues. Before crimping or bending anything, I suggest trying these adjustments. Once something is bent or otherwise modified, it is much more difficult to undo.
As with any troubleshooting, start with the simplest and least modifying fix first. Hope this helps.
 

ClipClock

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Bob are you testing it with hands pinned on? On French clocks often stuff moves forward without hands and causes problems. How is the hand tension? As Fitzclan asks, does the hammer twitch or lift on warning and is it in the relaxed/down position when running between strikes

Honestly I never line up the dots and must have done +/- 100 French clocks now. Its just a time and strike so if its set up right it'll run just fine irrespective of the dots. (But I know its a popular way of doing it and guess it works well for a lot of people).

Can we see a pic between the plates to see how its set up?

I agree with Fitzclan dont bend anything yet! I still think the most likely cause of the problem is the striking stalling
 
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Ralph B

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I think you've pretty much answered this yourself.
If you tested each hour position, and they worked ok, it's unlikely, in my experience, to suddenly change.

What is more likely is the strike not operating for some reason.
This could happen for hours, and not make itself apparent until the rack tail finally comes up against the big climb on the snail from the 12 o'clock position to the 1 o'clock.
It can't just slide up.
Up until now it's just been bumping down from hour to hour and the clock keeps going, now, after 12, it jams, and stops the clock.
If you had a Microset you could count the strikes and confirm it.

There are lots of reasons why the strike doesn't operate but it's not worth going there unless we know that's the reason.

If you suspect the problem is related to the hammer being "on the lift", and are not quite sure, then hold the hammer up yourself with a piece of wire and it will never come into play, and therefore couldn't be the problem.
 

BOBJAYR

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Wow, I'm at a loss. I've checked all the suggestions and cannot find a problem with the strike.

The warning cycle works as designed, the strike works as designed. The hammer is at rest and is
not lifted. There is no apparent worn rack parts etc.

My request: Can someone answer my question on the cannon pinion. Folks tell me not to crimp it and
I understand we don't crimp, bend items unless we know that is the problem but___________, as
far I know this cannon pinion is designed to be crimped to make it snug.

Right now its not snug but can be moved back and forth and me still being a new guy thinks this is
the problem.

Could someone tell me simply if I'm right or wrong on this one question.

thanks, bob
 

shutterbug

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If the cannon is solid, it's not designed to crimp. If it has some grooves cut into it, then it is designed to crimp.
 

ClipClock

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Yeah I've had to slightly squeeze these once or twice, but be careful, its easy to over do it. They arent supposed to be so tight they are hard to remove. Were you testing with hands on the movement? If not I'd try that first
 

shimmystep

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I'm not sure I entirely understand when exactly the clock stops. is the rack stuck against the drop off on the snail or has it got past that after striking successfully, is always the same spot?

One of the issues with these movements that can lead to some tail chasing, especially ones with less distance between the plate which are approx 28mm, is the issue of the spring barrel interfering with the intermediate wheel. The clearance is very fine. This occurs with wear to the bearing surface in the barrel cap and barrel, and can stop either train.
 

shutterbug

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I had one recently that would stop at random times. I had just repaired it, and was wondering if I had a bushing too tight or a bent pivot. On close inspection, I discovered that the rack tail was hitting the teeth on the minute wheel! A strangely designed thing, and putting a false minute hand on it solved the problem by keeping the wheel pushed back far enough to avoid the tail. The real hand was too long to run on my movement holder.
 

BOBJAYR

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Crimped the cannon pinion and that did it. The loose cannon pinion
apparently slipped over time. This caused the snail to
get out of proper alignment and allowed the rack tail to contact the
snail and stop the clock.

Bob