Strike Fan

Discussion in 'Clock Repair' started by Ed Schmitt, Dec 6, 2016.

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  1. Ed Schmitt

    Ed Schmitt Registered User
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    Aug 30, 2003
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    I'm now working on a Josef Kopfer & Shone, Tall case, two weight, bim-bam movement. I've had it for almost a month, and just getting started in working on it. Customer said that the strike side did not work most of the time. In looking at the movement as I slowly take it apart, I notice that the strike fan looked like someone worked on it before, then I noticed the other side of the fan. One side has an additional brass weight, and the other side is missing that addition, but you can see solder signs. First, is this added weight normal, and will I have to add one to the other side? Second, could this be the reason the strike side works occasionally?

    Ed Schmitt
    Shadows of Times Past
     

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  2. shimmystep

    shimmystep Registered User

    Mar 5, 2012
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    No, not normal Ed. It needs to come off. As you know as the fly turns the centrifugal force makes the fans open up and so increasing air resistance. Need to ask why they were added in the first instance. And the answer is probably to slow the strike train down. If the train is striking too quickly it may be that the fly components are too loose on the arbour. It might be that a spring that is too powerful has been put into the strike train.
    I would take that extra piece off and see what speed it runs as it is and try and figure out what was wrong to necessitate the additions.
     
  3. shutterbug

    shutterbug Moderator
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    I agree with shimmy, but do not think the added material would keep the train from working. It might work too slow, but should still work. There is another issue going on.
     
  4. R. Croswell

    R. Croswell Registered User

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    I agree with what's been said but will add that having just the one added piece will make it very out of balance. If starting the strike train is already marginal, then perhaps being out of balance could be the cause of the strike not working sometimes. I would begin by removing the remaining added piece and see what happens.

    RC
     
  5. Ed Schmitt

    Ed Schmitt Registered User
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    Thanks everyone for your replies. The movement is powered by weights not springs. I checked with the owner and had them look into the bottom of the case for a very small piece of brass. They found it and brought it to me. I've enclosed 4 more pictures. It appears that someone previously installed the two brass weights. picture 3 shows that the fan does expand like it should, but takes somewhat more pressure. Pic 4 shows a close up of the top of the fan, there is a tension spring on the top and bottom, and you can see a pin that goes through the arbor and it spins as the fan rotates. Again, do I add the additional piece or remove the one that is still attached.
     

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  6. shimmystep

    shimmystep Registered User

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    As mentioned by all, take it off Ed, then see what speed it runs back in place. Are the weights original?? How much do they weigh? If not original perhaps the strike weight is too heavy, causing the strike train to run too quickly.
     
  7. Ed Schmitt

    Ed Schmitt Registered User
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    shimmystep
    You have given me something to think about. I've tried to search the internet for information on this movement. No luck on anything for this movement. I did measure the weights. Strike weight is 7.5 lbs and the Time weight is 7 lbs. I have not seen this type of governor fan before. If you find any information on this movement, please let me know.
    Ed
     
  8. shimmystep

    shimmystep Registered User

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    Quite heavy weights. can we see some pics of the movement, the case and the weights? Do they appear to all go together?
     
  9. Ed Schmitt

    Ed Schmitt Registered User
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    shimmystep
    Here are some pics of the case, weights and movement. What do you think?

    Ed
     

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  10. shimmystep

    shimmystep Registered User

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    The weights don't look out of place do they. Was wondering if they looked obviously wrong, but no. Have to see how the strike train runs on the test stand without those extra pieces on the fly.
     
  11. BigAl

    BigAl Registered User

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    I am intrigued by what I see in your forth picture.

    f4.jpg

    For starters is the pinion slightly bent?

    It could just be the angle of the picture though. However, I am puzzled by the pin that you say goes through the arbour. It seems to me that its presence would prevent the normal free-wheeling of the fly during start up and when it finishes. Additionally the cut-out that the pin rests in, as shewn in the picture, looks very rough, has it been altered by someone?
     

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