Cylinder Escapement

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  • #48777
    chris mabbott
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    Being a patriotic American watch collector which, IMHO, are the finest pocket watches ever made, and the prettiest, I find myself in a conundrum. During my xmas family visit to ole blighty, an aunt who I haven’t seen in years, gave me someones pocket watch. Unfortunately it’s one of those nasty cylinder jobs. On first quick inspection, without my glasses, I could see the balance wobbling around, oh boy.

    When I got home I went to work and stripped it down, then washed my hands from the filth that was inside, while the parts soaked.
    The bad news was, apart from it being a Swiss cylinder, was… Shattered lower cylinder, broken top pivot, both top/bottom balance jewels shattered, two broken teeth on the escapement wheel, and four more broken rubbed in jewels on the train gears.

    The good news, it has a nice dial from a London maker and an English .935 silver case, hands are good etc. I’ve never worked on cylinders before so I’m kinda lost, thanks to a friend on NAWCC, who is a Swiss cylinder guy, I might have the parts which he can replace for me.

    My question is, the escapement with two broken teeth, I have an exact repalcement but, the shaft/pinion is different. How hard is it to remove the old pinion/shaft and fit it to the new escapement? Has anyone tried this before and if so can you provide any tips…. please :?

    Here is the watch..

    #54878
    chris mabbott
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    2

    #54879
    chris mabbott
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    Can we post more than one pic per post?

    #54880
    chris mabbott
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    Last

    #54881
    Bob Tascione
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    Hi Chris,
    It’s really easy if the turned pinion shoulder fits into the new escape wheel without having to open the hole. Really lucky too!
    The pinion is held in place by a light press fit (edit here – and rivet!) and can be removed by placing the wheel on the staking set table and putting the pinion into a hole that is close fitting. You can then tap it out of the wheel. It will come out easily. You should see that the shoulder is cut into the pinion leaves just shy of the dedendum minor dia. So you should see a tiny bit of the leaves left on the arbor. This helps bite into the escape wheel hub and helps keep it from loosening up and rotating. You’ll probably find that the replacement wheel likely has a higher shoulder (hub) than the original wheel and may need to be turned or ground down a little after pressing in the pinion arbor to allow for clearance for the pivot shoulder to reach all the way through. This is also important as you don’t want the wheel to ride on the hub but rather the pivot shoulder.
    If you need to open the hole a little and have questions about it please let me know.

    Enjoy,
    Bob

    #54882
    chris mabbott
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    Thanks for the info Bob, I’m going to go at it probably tomorrow and I’ll take a few progress photos to post for either accolades or to put me up against the wall 😆

    How does it normally go when re-fitting the pinion shaft into the new wheel, if it’s a friction/press fit, how can I prevent any distortion if all distances are correct? Would it be a preferable technique to use a jeweling lever to press it in or simply to tap it in using the hammer?

    Would I need to use a depthing tool along with the refurbished balance to check the mating, or would it be better to eyeball it once it’s mounted in the movement?

    Thanks, Chris

    #54883
    Bob Tascione
    Moderator
    • Topics Started: 38
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    Hi Chris,
    I probably should have gone into a bit more detail about how the pinion is attached to the escape wheel but had to run somewhere for a few minutes when I last posted. It actually should be lightly riveted to the wheel. The escape wheel is hardened so I find that just tapping the pinion arbor out causes the rivet to fold upward leaving it intact to be used again. These generally come out (at least for me) much easier than a balance staff without the rivet doing any damage to the hole. If the rivet breaks off or is removed then a light undercut can be made to the pinion shoulder for re-riveting. This is one reason that the hub height of the wheel will usually need to be reduced. Grinding can be done without having to temper the hub but if the hole needs to be reamed out to fit the arbor shoulder then you’ll need to temper the hole and shoulder anyway. You can then turn down the hub if needed. I do the tempering process with flame and a needle which is inserted into the hole. The needle is then heated until the hub and a tiny bit of the surrounding area just turns a dark blue color and is then withdrawn from the heat. It’s very important that the tempering doesn’t pass through the arms to the rim and into impulse faces. The hole can then be reamed to size. I use a staking set and punches to replace the arbor.
    If you have a depthing tool then this might give you a better perspective for checking to see if the wheel is suitable for the cylinder you’ll be using. I would think though that all real testing such as passage/fouling, drops, inside and outside shakes etc. would need to be checked while in the movement.

    Hope this helps Chris,
    Bob

    #54884
    chris mabbott
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    That is a HUGE help Bob, thank you for taking the time on new years eve to explain in depth, although for us “seasoned guys” the new year is just a new tax period 😆 It’s more about having a good meal and an early night 🙄

    Cheers, Chris

    #54885
    Bob Tascione
    Moderator
    • Topics Started: 38
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    You bet Chris!
    If you zoom in on your pic you can see why I say the leaves can bite a little into the hub to keep it from rotating. The ends of these leaves become the rivet and can bite into and help lock the arbor into the wheel. If the leaves were turned off then the rivet would have a smooth underside and might be more prone to slipping. Then again I don’t know how effective that locking would be with a hardened escape wheel as the pinion is almost certainly tempered a little to allow for riveting without breaking and to protect the pivot. Anyway…at least that’s my theory. Might be wrong but kinda makes sense to me! I have seen escape wheels that were not riveted on but just pressed in place. That doesn’t seem like good practice to me. These may have been replacement wheels or pinions and not how they were manufactured? I’m sure others up here have experienced loose and tilted cylinder escape wheels. Maybe this could have been avoided with a good rivet. Of course the rivet also helps keep the wheel from falling off of the arbor!
    Please let us know how it turns out Chris,
    Adios for now!
    Bob

    #54886
    chris mabbott
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    I would like to revive this thread as I haven’t yet found a workaround for this watch….

    #54887
    arutha
    Participant
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    I have a few cylinder bits and bobs floating around, if you let me have the outside diameter of the escape wheel, and overall length I can have a look and see if i can find you one and a cylinder and balance wheel to match. If i can find a match the main issue will be pivot size so you might need to re-jewel or possibly shorten the escape wheel arbor length and possibly the cylinder plugs? Failing that I might have a complete movement that will just need a service.
    Paul.

    #54888
    arutha
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    Bump – Ha I did reply but you didn’t get back to me! :)

    #54889
    chris mabbott
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    😮 Oops, sorry Paul, I must not have seen it and the thread got lost under the pile, I’ve seen it now though, thanks buddy :)

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chris mabbottCylinder Escapement