Terry strike side issue

Discussion in 'Wood Movement Clocks' started by jboger, Aug 29, 2019.

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  1. jboger

    jboger Registered User

    Jan 7, 2019
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    This post concerns the strike side of a T&S Terry-type movement. First, I have a Terry movement in a Terry Jr case (pillar and splat). I dismantled the movement, cleaned all the pivot holes (green, oily gunk), and reassembled the clock. It runs beautifully, and the strike side strikes the hour on the hour w/o skipping. The only attention I paid to the strike side when re-assembling was to make sure that as the center wheel turned, it lifted one of the levers (a wire) which in turned lifted another wire (to wheel S3) that released the train so that the weight would drop and the hammer would strike. All good.

    I have another Terry-type T&S movement that wasn't fully running when I got it. I dismantled the movement, cleaned it, and reassembled only the Time side. Runs with good motion to the pendulum (after a repair to two broken teeth). So I added the Strike train and did the same thing I did as described above. Only thing, the outcome is different. The time side continues to run beautifully. And the clock strikes the hour on the hour. Only problem is, the movement decides to skip some of the hours before the train stops. That is, the clock continues to strike into the next hour. The lever will fall into the slot on the count wheel, which I think would drop another wire into S3 and stop the train. But no, the lever rises up again out of the count wheel slot, and the weight continues to drop and the gong to ring. Then it stops. And when I write that it stops, it's not because the weight has run its course but because the lever has fallen into one of the hour slots on the count wheel and stopped the train by stopping S3 from any further rotation.

    If I assume that (1) all wheels are good (they are) and (2) the wires that trip and stop the Strike train are functioning properly (that is, not bent)--then do I have re-assembly problem that I don't understand? Am I not aligning something properly on the Strike side when I put the movement back together? Am I missing something with regards to S3 or the pin on S4? Because it sure does look like the Strike side is working properly except for continuing to chime when it shouldn't.

    I don't want to start bending wires that otherwise look fine until I rule out that I have a re-assebly problem. The Terry clock I've taken apart several times and always have success putting it back together. I don't understand why I don't have similar success with this other clock.

    Sorry for the long post, but I needed to describe the problem.
     
  2. gleber

    gleber Registered User

    Jun 15, 2015
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    The lever dropping into the slot doesn't stop the strike train. It only allows another lever to drop into the correct position to stop the train. If the count lever is falling into the slot properly, it is probably the other lever. Without looking at it, and if I remember correctly, there is a stop lever on the upper lever arbor that blocks a pin on S4. The notch in S3 only allows the count lever to drop (and the count wheel stops it from dropping too far or letting it drop enough), but it doesn't stop the train.

    Two possible issues:
    1. The pin or stop lever is missing.
    2. The S4 is out of sync, so the pin is missing the stop. This would be continuous until the weight reaches the bottom.
    3. Make sure the stop lever is arresting the pin correctly (near the middle) and not just barely on the edge. This could explain why it might stop sometimes and not others.

    Tom
     
  3. jboger

    jboger Registered User

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    The pin on S4 is present. I see the wire (with a flange on the end) that stops S4 from rotating. I will check the alignment.

    Important question: Are you telling me that it is this pin on S4 in combination with that flanged wire that actually stops the Strike train and NOT the lever that falls into a slot on S3 when the count lever drops?
     
  4. gleber

    gleber Registered User

    Jun 15, 2015
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    Yes, the pin on S4 stops the train when the flanged stop lever drops in its path.

    How it all works:

    A few minutes before the top of the hour the cam on the minute arbor lifts the long lever on the lower arbor, and the warning lever which is on the same arbor. The long lifting lever also simultaneously lifts a lever on the upper upper arbor which lifts the count lever out of the slot and the stop lever is lifted to release the pin. S4 start to rotate, but is stopped by the warning lever. The clock is now in Warning and stays this way until the lifting lever drops off the cam at the top of the hour. When the lifting lever drops off the cam, The warning lever moves out of the way and then it's "off to the races" - the train starts to run. As S3 turns, an inverted cam potentially allows the count lever to drop into an indentation on each 1/2 revolution (the cam has two indentations 180 degrees apart). When the count lever drops, the count wheel either stops it from going into an indentation or lets it fall into the indentation. If the count wheel stops the count lever from dropping into an indentation, the train continues to run because the count lever keeps the lever on the upper arbor from dropping into the indent and therefore the stop lever from dropping in the way of the pin. When the count wheel allows the count lever to drop into a slot, the lever on the upper arbor drops into the indentation and the stop lever drops enough to block the pin on S4 and the train stops. This repeats at the next hour.

    The indented cam on S3 does not arrest the train. When I was first learning, I thought it did, but it only allows the stop lever to drop in the way of the pin on S4, which can only happen with the count lever drops into a slot on the count wheel.

    While I understand how it works, I don't think I could have ever designed it. I hope this explanation is understandable. It would be better with an animation.

    Tom
     
  5. gleber

    gleber Registered User

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    You will probably find that the pin is not synchronized with the stop lever, so the stop lever is dropping, but the stop pin is not in the right place. When it does get to the right place, the stop pin has already lifted out of the way again by the lever coming out of the indentation and lifting the stop lever.

    You will need to split the plates and rotate S4 vs S3 to get the pin in the right place at the right time.

    Tom
     
  6. gleber

    gleber Registered User

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    I just re-read your problem description. The first time I read it, I thought it said it stops when the weights reach the bottom, but now I see it stops normally sometimes. This could be from synchronization, but now more likely the alignment of the stop lever and pin, or the count lever is not dropping cleanly into the slot and doesn't drop enough when it doesn't stop. You should check both.

    Hopefully you will find it, but let us know if not.

    Tom
     
  7. Jim DuBois

    Jim DuBois Registered User
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    Jun 14, 2008
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    Timing of the strike train is semi-critical on these wood works. Some of the trains in some of the movements have index marks on them telling you where to position the wheels before you put on the top plate. Some do not.

    But;
    1)The hammer lift lever has to be free of the hammer lift pin when the movement locks
    2) in most cases the pin on the warning wheel should be no further than about 1/4 turn from the stop lever when the movement locks up
    3) the movement locks when the count wheel finger drops cleaning in the slot and it should be about centered in the slot
    4) the movement is locked by the pin on the 4th wheel, but the timing of the hoop wheel and the 4th wheel and the hammer lift wheel is most likely your issue.

    A very complete write up of this process with photos can be found in "Extreme Restoration" by T.E. Temple but copywrite prevents copying and sharing of those details here.

    th.jpg
     
  8. Steven Thornberry

    Steven Thornberry User Administrator
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    Use of the conversation function for sharing this information would be allowed.
     
  9. jboger

    jboger Registered User

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    Tom, Jim:

    I basically understand how it works; I did not know that it was the the stop lever against the pin on S4 that actually halts the train. That is very important information and clears up at least one mystery for me.

    It appears I probably do have what I've been calling an "alignment problem". Really a synchronization problem. The levers (wires) look as if they have never been bent and I did not want to start doing that now. I confess, I'm not there yet as for how to get the synchronization right. And I don't understand why every T&S brass movement I've put together didn't have this problem. I guess I will need to pull the movement apart--again.
     
  10. jboger

    jboger Registered User

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    "You will probably find that the pin is not synchronized with the stop lever, so the stop lever is dropping, but the stop pin is not in the right place. When it does get to the right place, the stop pin has already lifted out of the way again by the lever coming out of the indentation and lifting the stop lever."

    This sounds like my problem. I have never paid attention to this detail. I understand the problem, but I'm there yet how to align things properly so that everything is synchronized. I will work on this.
     
  11. jboger

    jboger Registered User

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    I have yet to do this, but I believe Jim DuBois's pictures shows the necessary alignment . . . Off on a at trip. When I get back I'll see if I can find the time and patience to pull the movement apart again. I will (1) put the count lever in the "down" position; (2) rotate S3 so that another lever falls into one of the S3 indentations; and (3) rotate the S4 wheel so that the pin and and stop lever (flanged) are touching. All of this should align the pin on S4 to hit the stop lever when the count lever is all the way down in the count wheel slot. This should stop the train and the weight descending. I tthink I may have it. We'll see when I get back.
     
  12. gleber

    gleber Registered User

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    You need to make sure the lever has time to drop when the clock is running. Sometimes a static sync make be a little too late when the wheels are turning and the pin will pass before the stop lever has time to drop and arrest it.

    Tom
     
  13. jboger

    jboger Registered User

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    Success! Actually I have a third wood movement, an Ephraim Downs clock, which has been de-deviling me. I've lost count the number of times I took the movement apart. One time, the Strike weight descended to the bottom, the movement chiming all the while. Other times it displayed the same symptoms as the clock I described in the original post: the Downs clock would chime on the hour but continue to chime until the stop lever stopped S4 from rotating (before the weight hit bottom).

    It's this clock I decided to tackle first, not the one that started this thread.. Now the Downs movement is functioning properly. When I get back from my trip I will tackle the other clock that started this thread, a Waterberry, South Carolina clock. (Yes, WaterBERRY.)

    This thread has been of much value to me. I can not thank enough the people who took the time to guide me through this, in particular Tom and Jim DuBois. Thank you. I now expect success with the South Carolina clock.
     
    Jim DuBois likes this.
  14. gleber

    gleber Registered User

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    Glad to hear that you got it running!

    Tom
     
  15. jboger

    jboger Registered User

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    Now happy to report that the Waterberry clock strikes properly.
     
  16. jboger

    jboger Registered User

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    A thought. Wheel S3 has two slots into which a lever falls by gravity. These two slots are widest at the top and taper slightly towards the center of the wheel. I think the width of the slot at the top determines how much play one has when positioning the pin on S4 relative to the stop lever that prevents S4 from further rotation. If the distance of the S4 pin from the stop lever is less than the width of the S3 slot when reassembling, then the strike mechanism will be properly synchronized. I sense this to be true but I am by no means certain that I'm correct.
     
  17. R. Croswell

    R. Croswell Registered User

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    I think Jim summed it up pretty well in post #7, but I'll try to add a few hopefully helpful comments.

    1. Intermittent and run-on strike issues often direct our attention to the upper train, but the problem often originates in the lower train. The sync between S2 (the strike pin wheel) and S3 (wheel with the maintenance cam) is the first place to look. Sometimes, as already mentioned, there will be timing marks on the S2 wheel and S3 pinion. Pinions are marked by the corner of one tooth clipped off. We need the lever to drop into the cam slot just after the hammer falls and the count wheel must be in position to receive the count blade. We do not want the count blade dragging on the rim of the count wheel. Even if it doesn't look bent, these blades have often been bent by those messing with strike problems, so it may be necessary to adjust slightly. I usually begin with just S2 and S3 and the levers in place. Once this action is correct, if there are no timing marks I will add them.

    When the count blade and the cam lever drop (after the hammer fall) the stop pin on S4 should be not more than 1/4" away from the stop pin as Jim also mentioned. If the stop pin is too far away, the cam on S3 will start to raise the stop lever before the pin is arrested. The lever pivot holes wear and over the years it is likely that things have been fooled with, so make sure the flat end of stop lever has good contact with the stop pin and not just catching on the edge. But also make sure the stop lever completely clears the stop pin when the strike train is running, Make sure the stop lever is tight in the wooden arbor as well. Most of the problems I have seen are related to incorrect sync between S2/S3 and S3/S4 or misalignment of the count lever blade or the stop lever.'

    I've never seen a movement of this type that locked on the maintenance cam, although that is common in brass clocks, especially New Haven and a few others.

    Glad you have this one running.

    RC
     

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