French Marti Rack and Snail Strikes 2 at highest point on snail where one should be

Discussion in 'General Clock Discussions' started by clocks55, Jun 26, 2015.

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  1. clocks55

    clocks55 Registered User
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    I have lined up the 3 dots on the appropriate gears, and it strikes ok at 12, 12:30 but when it reaches the 1:00 position the rack falls all the way down and can not be gathered, so the strike runs completely down. At what should be one on the snail, the highest point on the snail, it strikes twice. I have also tried reindexing the motion work, but still get the same results. french marti movement.jpg Picture shows rack tail at highest point on snail with the gathering pallet about to grab two teeth.
     
  2. harold bain

    harold bain Registered User
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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    Wedge a screwdriver between the rack and the rack tail and make a small adjustment so that only one tooth is gathered. As for the rack falling all the way down, perhaps with the hands set up properly with a washer and pin on the minute hand, the rack will stay back enough that this won't happen.
     
  3. Tinker Dwight

    Tinker Dwight Registered User

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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    The highest point should be 1.
    It sounds like the rack and the rack tail are not right relative to each other.
    After adjusting the angle between the two, you'll need to reset the
    hour hand to match.
    It is usually a tight fit between the rack tail and the rack but it
    one should be able to adjust it.
    I recommend removing it from the movement and determine
    how much angle it needs to be moved by and make a template.
    It is a tiny amount but you don't want to damage
    the movement by slipping and it will be easier to get tools
    around it.
    Tinker Dwight
     
  4. shutterbug

    shutterbug Moderator
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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    To me, it looks like it's set to strike twice at 1:00. The rack tail looks to be a friction fit. Move the tail part away from the rack part and see what you get. TINY adjustments are the key. But that falling all the way down part is problematic. The tail is missing the snail completely.
     
  5. clocks55

    clocks55 Registered User
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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    I thank you 3 gentleman for your excellent suggestions, as usual with this fine forum, the answers come faster than I can apply them, but I will let you know how things work out, this is the last issue left with this clock, I have been working on it for almost a year, and had given up on it many times, but the customer is pleasant and it has been a challenge.
     
  6. ClipClock

    ClipClock Registered User
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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    I always hesitate to make suggestions as I'm not the most experienced, but I have done a lot of French clocks, they're my absolute favourites :)

    Yes it does look like its set up to strike two. I wonder if you still might have one more tooth you can rotate the snail, it looks to me like the rack tail is landing quite far along the snail (for a French clock). I find they like to barely make it onto the high point of the snail.

    Re the dropping all the way down, French clocks seem to be little devils for the hour pinion edging forward unless the hands are firmly pinned. Are you sure this didnt happen in your case? Seems odd it would only drop all the way down for one strike.

    On all the French clocks I've done the rack and rack tail are extremely firmly attached to each other and appear to be almost 'one piece'. I personally would not like to try to change that unless its a last resort!

    One other thing I'd check is the rack hook, it needs to be firmly held on its squared arbor. I don't mean firmly pinned, I mean that the squared hole needs to be snug on the arbor. I've had inconsistent striking due to that being too sloppy and have had to tap lightly around the hole to rectify the problem

    Good luck :)
     
  7. clocks55

    clocks55 Registered User
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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    rack template.jpg I made a template after measuring how far the rack tail would travel for one tooth of the rack. I then opened up the angle between the rack and the rack tail by that amount. Now it works perfectly striking 1 at the highest point and 12 at the lowest point of the snail, and due to the changed geometry the rack no longer falls below the gathering pallet between 12 and 1, thanks again for all the help, kindest regards, Peter Elmendorf
     
  8. harold bain

    harold bain Registered User
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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    Good work, Peter.:thumb:
     
  9. ClipClock

    ClipClock Registered User
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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    Wow what an usual thing. Cool you managed to fix it!
     
  10. Talyinka

    Talyinka Registered User

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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    Well done. This is the type of issue you come across all the time. The rack and the rack tail are lose on their centre, or the rack pin or rack pivoting centre are worn to produce excessive play. You often need to replace the cylinder enveloping the rack pin and solder or press fit in a new one.

    Another thing to look our for is uneven wear around the rack pin causing the rack tail to miss the hour snail to one side or the other, again a common fault often discovered after carrying the clock in a non-vertical position and after putting it down noticing that the strike count is no longer correct.
     
  11. shutterbug

    shutterbug Moderator
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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    :thumb:
     
  12. Tinker Dwight

    Tinker Dwight Registered User

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    Re: French Marti Rack and Snail Strikes 2 at highest point on snail where one should

    In the picture, it looked to be exactly one tooth off. Rather than
    wear, it looked to be misadjusted. That is why I suggested
    moving rather than looking for warn parts.
    Tinker Dwight
     

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