Bent Pivot.

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  • #48393
    alwood7
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    Hi everyone,My name is Alan Clifton and I am a new subscriber to Tascione.I live in the UK.in a place near Selby in North Yorkshire.I am 62 years old and admit that I have taken up clock repair a little late in life, but I needed a good hobby for retirement and thought clock repair would be a very interesting hobby.I have only been “going” a few weeks but have jumped straight in with both feet.After taking apart and cleaning/oiling a couple of small mantle clock movements I thought I would go for something a little more complex.To this end I am now trying to repair a “Jauch” 3 Train Westminster chime movement(Weight Driven)I managed to replace a bush that was badly worn and preventing the quarters chiming,but on re-assembly I managed to bend the pivot on the escape wheel.Would anyone be so kind as to tell me the best way to straighten this and make it true?Does it require heat,or can it be done cold?Will it need a new part and if so wheres the best place to get one?:Thank’s in anticipation Alan.

    #52298
    arutha
    Participant
    • Topics Started: 85
    • Total Posts: 1536

    Hi Alan and welcome :)
    Good job its not a French clock as the pivots are very hard and will snap 9 times out of ten. Bending escape wheel pivots was a problem for me when I first started, I was so worried about gears popping out I used to apply just a bit too much pressure when putting the mechanism all back together and would end up having to take it apart as I had bent an escape wheel pivot. The easiest way to do this is if you have a watchmakers lathe, put the bent pivot in the collet and use the pointed end on the tailstock runner as a guide to gently bend, a little at a time until it runs true. If you dont have a lathe then you can try to do it by eye, hold the arbour in a drill chuck and use a cheap small pair of pliers with the inner jaws polished to again gently, a little at a time bend the pivot until it looks true. Once you think it is true just try it on its own in the plates to see if the wheel runs ok and is not binding. The pivots are normaly soft enough that you can bend them back without fear of breaking them. You do not need to use heat. Worse case scenario, if you do break the pivot off, send it to me and I will re-pivot it for you if you dont have the equipment, I too live in the UK in sunny Weston super Mare.
    Good luck and let us know how it goes.

    #52299
    willofiam
    Moderator
    • Topics Started: 75
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    hello alwood7, Alan, welcome, I know what you mean by jumping in with both feet, I too started out with clock repair as a hobby but soon after it became something much more…..completely exciting 😮 , fun 😆 , works the old noggin 🙄 , calming ;) , challenging :geek: , rewarding :D , fascinating 😯 , and more!!! about your bent pivot, Paul is right on as always and I would stress, be gentle ;) I have been brainstorming possible other ways to check your pivot if you do not have a jewelers lathe. maybe by chucking it up in a drill press???? or 2 same size blocks so that you can turn the wheel on the arbor ends and watch the pivots as it rolls, carefully adjusting in small increments until no visible wobble. Basically trying to get both pivots to have the same center by using something to measure that. have fun, William

    #52300
    alwood7
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    • Topics Started: 1
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    Hi Arutha,and Willofium,Thanks for the suggestions on the bent pivot.I am not in possession of a lathe so I think the best idea is to try and bend it cold.I like the idea of the two metal blocks,I presume you would roll the pivot between these and this will show the wobble at the other end of the arbour slowly bending the pivot until this wobble is reduced to zero?Anyway I’ll give it a try and thanks once again for the suggestions Alan.

    #52301
    arutha
    Participant
    • Topics Started: 85
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    You could make do with two metal blocks as William suggested but it would save time and material just to try it between the plates?
    Just a thought :)
    Paul.

    #52302
    willofiam
    Moderator
    • Topics Started: 75
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    Great idea Paul, didnt even think of it 🙄 , I love brainstorming ideas!!!! so if you put the plates together to roll the pivots along any of the edges, I suppose as long as the edges are smooth and parallel, that might work better, you are using the pivots and not the arbor, which in some case can be bent a little, thanks Paul, see yah soon, William

    #52303
    alwood7
    Participant
    • Topics Started: 1
    • Total Posts: 3

    Thanks everyone for your suggestions,I did try spinning the pivot in a drill but this wasn’t very succesful as the drill was too fast to see where the bend was.I tried rolling it between metal blocks,and this did show the wobble,but in the final analysis you have to see the bend visualy to effect a repair,so I looked at the pivot with an eyepeice and sighted down a pinion leaf to the pivot.Any deviation from straight shows up as a slight displacement to left or right and I was able to straighten th e pivot by this process.I have since replaced the part in the movement and it seems to be working ok.Thanks for all your efforts I will probably require further advice as I am only a novice,see you all later.Alan

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alwood7Bent Pivot.