Chelsea Ship's Clock problem

Discussion in 'Clock Repair' started by Jeff Salmon, Sep 30, 2019.

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  1. Jeff Salmon

    Jeff Salmon Registered User
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    Apr 11, 2002
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    Hopefully someone can direct me to fixing a problem with this old Chelsea mantle clock with ship's bell strike serial number 74555 (about 1912). It was in very bad shape when I received it from a client. The case was badly tarnished, the front glass was broken, and, to make matters worse, the movement had been badly treated and was not running. I have repaired many Chelsea clocks over the years, but the previous attempt to repair the clock was obviously done by someone with no experience dealing with Chelsea ship's bell clocks. The movement was previously bushed and many of the bushings were tight and some arbors had no end shake. The pivots needed polishing. The mainsprings were no good, and there were other repairs that needed to be made. Fortunately, the escapement was not damaged.

    Looking at the rear of the clock, you might notice that the rocker annex spring was soldered to the annex arm. There are now 2 tiny screws on the top edge and the spring has been re-formed to a more appropriate shape.
    Notice that the snail has the mark at the 5 position (in black), in order to get the rack tail to hit the snail at the appropriate spot. I often refer to the drawing shown for set up, just in case I miss anything. The drawing shows the dots on the snail, minute wheel and the hour pinion to line up. However, if I do that then the clock is not set up properly. It does not seem like the snail has been moved to the wrong place, relative to the dot.

    After a lot of adjusting on the rocker annex spring, and the rocker itself, I have the tension on it working well. My problem seems to be that when the pins on the lifting wheel come around to lift the hammer, the hammer is not given a chance to fully drop and hit the gong as the next pin is already lifting the hammer again. It's as if the pin on the hammer arbor is too long and the hammer gets lifted too high. When the second lifting pin lifts the hammer, the hammer drops to a low enough position to hit the gong. It does not look like the pin on the hammer arbor has been played with. The movement is set up properly, as I have usually done, with the arm on the hammer arbor (that gets lifted by the lifting pins on the 2nd wheel) is set so the strike train stops with it between the pairs of pins on the 2nd wheel. The pin on the 4th wheel is lined up with the end of the fan blade.

    If anyone has any suggestions, please let me know.
     
  2. Jeff Salmon

    Jeff Salmon Registered User
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  3. bruce linde

    bruce linde Technical Admin
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    Nov 13, 2011
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    impressive work, impressive knowledge, impressive clock! :cool:

    i would make the hammer and supporting rod look as much like the sketch as possible and then see how it behaves. right now, the hammer looks like it's choked up on the rod and should be more to the left... and the rod should be straightened.... might get you closer to the required geometry.
     
  4. Jeff Salmon

    Jeff Salmon Registered User
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    Apr 11, 2002
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    Bruce,

    Thanks very much for the reply. I have adjusted the hammer wire and have had some better luck. I will also move the hammer over to the left to see what that brings. I notice that the hammer assembly seems loose on the arbor (the shaft with the cross-pin). Perhaps this was changed for some reason. I will make a new sleeve for the hub to get a snugger fit. Sometimes I need an extra set of eyes....

    This particular clock was bought new by the current owner's parents. When I disassembled the case for refinishing, all the brass that was not 'improved' by the care that was given over the years, looked like new. More to follow.

    IMG_2970.jpg
     
  5. Jeff Salmon

    Jeff Salmon Registered User
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    Bruce:

    I am still having trouble with this. I had to make a new bushing for the hammer hub as the hammer assy. was loose even when pinned (perhaps replaced earlier). Now the hammer assy. is snug on it's arbor when pinned. I fit a new hammer arbor banking pin as the old one was very bent. I also straightened out the hammer wire by twisting it such that when seen from the side it looks like it makes more sense. Notice in the new picture that the hammer rests just above the gong like it should. My problem continues to be that during the striking, the hammer is raised too high on the first lift to hit the gong, then the 2nd lifting pin happens too quickly for it to strike. The result is such that I get the 2nd strike only, the first has the hammer too high.
    I looks like the previous repairer did something to the end of the rocker arm and you can just see a discolored area at the end. Perhaps there is too much tension on the rocker annex spring. Your thoughts appreciated.

    IMG_2974.jpg
     
  6. bruce linde

    bruce linde Technical Admin
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    flattered that you think i know what i'm talking about. :cool:

    your hammer rod (and position of hammer itself) seem short to me... at least compared to the sketch you provided above. on the other hand, making them match the sketch would smack them into the piece holding the curled gong.

    i really am not the guy who's going to help you solve this... but maybe you could take some video, upload to youtube and then copy and paste the url here so others could see the hammer/strike in motion?

    i would also remove the gong so the view was just movement and hammer.
     
  7. Uhralt

    Uhralt Registered User
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    I believe that the lever that is pushed by the strike wheel might be too long, thus providing too little clearance between strikes. Maybe it has been replaced previously.

    Uhralt
     
  8. Jeff Salmon

    Jeff Salmon Registered User
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    Uhralt,

    I was thinking the same thing, actually. I'll have to check that out. Maybe I can compare it to another, more modern Chelsea that I have. I have compared the old rocker and a newer one and there is very little discernible difference.

    Bruce,
    The end of the hammer wire is too close to the gong block.

    The video sounds like a good idea.
     
  9. bruce linde

    bruce linde Technical Admin
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    as long as you're thinking videos, look for related ones on youtube... they may reveal the answers you're looking for...
     
  10. Jeff Salmon

    Jeff Salmon Registered User
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    Today, I have made a lot of progress, although it is painful. I have spent lots of time on this one, trying to figure out the many problems. Uhralt is correct. The lifting wire is too long. However, it appears that the arbor and probably the hammer wire are incorrect replacements I suspect that these parts from a 'house strike' clock were swapped with a ship's bell clock. Attached are several pictures showing differences between the parts. First off, the lifting wire on (the problem clock is #1) is slightly longer at 8.39mm, while the (ship's bell--correct one-- is #2) is 6.31mm. If I remove the hammer assy. from the arbor on #2, I can get the lifting pin to just clear the arbor above it. Not so with #1. Looking at the other pictures of the 2 hammer arbors shows other differences: Notice that in the picture, with the taper pins relatively parallel, the lifting pin is as a completely different angle. The short pin is to hold the end of the wire tension spring. Notice also, in the picture showing the 2 hammer wire hubs: the blocking pins are at different positions. The two hammer wires are also of different lengths. The longer example for clock #1 appears a better length in relation to the gong. The longer hammer wire probably won't be able to make the quick strikes, though. I always thought that the swing of the hammer on this clock (#1) was way too much. By shortening the lifting pin on the problem clock, I may get better performance and I can shorten the hammer wire if I need to. I am not sure of the differences in the angles between the lifting pin and the hammer hub is 'correctible'. I may have to attempt to make a new arbor.

    IMG_2988.jpg IMG_2983.jpg IMG_2987.jpg IMG_2989.jpg IMG_2982-1.jpg
     

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