Pivot replacement??

Discussion in 'Clock Repair' started by NEW65, Sep 28, 2019.

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  1. NEW65

    NEW65 Registered User

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    #1 NEW65, Sep 28, 2019
    Last edited: Sep 28, 2019
    Hi Chaps,
    Please check this link out:
    Clock Wheel Quick Pivots
    I know about pivot replacement as I have done many BUT I would like your views on this method... it sounds good?
    Cheers :)
     
  2. Uhralt

    Uhralt Registered User
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    Their description says:
    "Turned steel pivot ends for projects where professional re-pivoting is not feasible"

    I would limit their use to this purpose.

    Uhralt
     
  3. NEW65

    NEW65 Registered User

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    Thanks Uhralt - I was thinking more on the basis of saving time using this method... thanks anyway
     
  4. Kevin W.

    Kevin W. Registered User
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    Not sure how trust worthy they might be lower in the train where more power is applied.
     
  5. Willie X

    Willie X Registered User

    Feb 9, 2008
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    There are rare cases where you will find a split arbor. This happens sometimes on old clocks with rought iron arbors, or a botched re-pivot. This is the only time I would consider using the item in question. Willie X
     
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  6. Bruce Alexander

    Bruce Alexander Registered User
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    Don't do it!

    I've only seen one case in which three of these pivot caps were attempted. They were off-center and poorly aligned with the arbor. The mechanism was an absolute mess. After giving the owner a quote to set the arbors right, he decided to scrap the movement (Seth Thomas 124) and seek a replacement off of eBay. I'm fairly confident that I could have rebuilt the gears in question but all things considered, it was a wise decision on his part.

    I defer to Willie's judgement on where these things might be appropriate. No one has trusted me with a movement that old. Considering movements that I do have experience with, I can think of no good reason to use these things. Hacking back the Arbor to make room for them is butchery in my book.

    If one doesn't have a Lathe to accurately re-pivot the arbor, farm the work out so that it is done properly... is what I think.

    Bruce
     
  7. Bruce Alexander

    Bruce Alexander Registered User
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    Here are some photos of the attempted Pivot Caps I reported on earlier. The pics aren't very high-resolution so you can't see just how poorly they were placed. I've included a few non-related repairs to give some idea as to the demonstrated workmanship.

    I think that the "small, medium, large" nature of the system probably doesn't lend itself very well to the wide range of arbor diameters one is likely to encounter. The proper amount of end-shake is probably going to be a crap-shoot too. I suppose that with experience one could acquire some proficiency at placing these things but I can't imagine getting the degree of accuracy necessary without the use of a Lathe so why bother with them?

    Please don't.

    Pivot Cap 1.JPG Pivot Cap 2.JPG Pivot Cap 3.JPG Fly Repair.JPG Prior Chime Barrel Repair.JPG
     
  8. leeinv66

    leeinv66 Moderator
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    I have made and installed pivot caps on several occasions. In most cases they were used to repair damage from attempts at pivot replacement by previous (I use the term loosely) repairers and once to repair a shattered arbor end in an English eight day longcase movement I own. These repairs required no hacking or butchery to perform. I agree with Willie's recommendation on when this method of repair should be considered as pivot caps shouldn't be seen as a cure all.
     
  9. Bruce Alexander

    Bruce Alexander Registered User
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    I can't argue with your experience Peter and I'm not trying to.
    The OP is evaluating these to...

    ... on that basis, and on the basis of what I've seen, I think that he shouldn't.

    Regards,

    Bruce
     
  10. R. Croswell

    R. Croswell Registered User

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    I would not use these in place of "normal" pivot replacements, or to save time.

    RC
     
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  11. Bruce Alexander

    Bruce Alexander Registered User
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    Yes. I suppose that's what I'm saying.

    Here are the details of these Pivot Caps from Cousins website:

    • Steel
    • Original pinion shaft may need adjustment (arbor?)
    • Set, Pack of 12 (2 of each 6 sizes)
    • Individually Graded Packs of 2
    • Designed to be friction fitted to the pinion (arbor?)
    • They can also be held on with a very small amount of super glue

    I think these "small, medium, large" pre-manufactured caps are a far cry from something someone might custom fabricate under a special set of circumstances. As I recall, the failed attempts I ran across fit the arbors very poorly. One was clearly "crimped" and none of them ran true. I don't know if they were held on with super glue or not though. These things turned the movement in question into a donor.

    I wouldn't use them.
     
  12. shutterbug

    shutterbug Moderator
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    Actually the pivot caps are harder to put on than it would be to repivot in the usual way. If you don't have a lathe, farm the work out to someone who does.
    The caps require that the arbor be measured and cut off precisely. The cap has to be placed and attached, typically with solder. After that the pivot has to be sized. After all that, you now have a wheel that can never be restored to "normal" again, and it will have to be pitched by a future repairman trying to restore the clock to it's former glory.
    Unless the arbor is split, don't go that route.
     
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  13. Kevin W.

    Kevin W. Registered User
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    Its sad to me that clock part supply places sell such thing slike this and other bodges, like screw in bushings too.
     
  14. Bruce Alexander

    Bruce Alexander Registered User
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    That's what this reminds me of too Kevin.
     
  15. R. Croswell

    R. Croswell Registered User

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    And just as hard to rectify when it goes wrong, which it usually does.

    RC
     
  16. Bruce Alexander

    Bruce Alexander Registered User
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    I think that in some cases it may be harder RC.

    I've seen a small number of Screw-Ins and Pivot Caps which didn't go well. In one case, a Screw-In on a 2nd Wheel failed and caused a lot of damage to the gear train. That was a major disaster which informed my strong opposition to those things.

    In general, though, I think it's easier to reverse a Screw In Bushing (plug, locate center and drill) than it is to reverse a capped steel Arbor. I suppose one might fabricate a custom pivot cap (as described by Willie and Peter) which actually fits the arbor; the pivot hole/bushing; and runs true between centers with the proper amount of end shake. Outside of that, you'd probably have to rebuild the wheel by fabricating a new Arbor and going from there.

    Those with good Machinist skills and equipment could take either approach easily in stride but the tolerances are a little tight and it would take anyone a lot more time to reverse and correct a pivot cap vs. simply re-pivoting a sound arbor in the first place.

    In the wake of bad results with these things, one ventures far beyond routine maintenance and well into the realm of repair/restoration. They are marketed as short-cuts. Anyone with the skills to make them work would most likely not see any advantage in using them. Yet there must be some demand for them. I don't understand it. As Kevin says, it's just "sad".

    Regards,

    Bruce
     
  17. Kevin W.

    Kevin W. Registered User
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    Unfortunately to some with little or no experience these bodges may look very promising. But i the long run could be way more costly to repair a bodge and make it right again. Cheaper to do it right the first time.
     
  18. kinsler33

    kinsler33 Registered User

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    A few years ago I was terrified of repivoting, so I bought a little assortment of these emergency pivots. The bag was branded "S. LaRose," in fact. I looked at them balefully on occasion, having last seen them as I re-organized my collection of tiny clock parts into dozens of clear-plastic Chinese pill bottles.

    And there they will stay, for I found Al Takatsch's video on re-pivoting and purchased his centering tool (which you could actually make yourself.) You don't really need a real lathe with this surprising method: my bogus no-tailstock sewing-machine-motor-powered sort-of-lathe works quite well.

    I didn't really believe it would work, but once you file off the remains of the deceased pivot, chuck the wheel into anything that will rotate it, and apply the centering tool to produce a starting dimple in the center of the end of the arbor, you can chuck an appropriately-sized twist drill into a pin vise and, with the arbor spinning, accurately drill a hole right down the center of the arbor. Whenever the drill starts to go off-course, you'll feel the pin vise try to spin, so you correct its direction until it feels right again. Pull the drill out occasionally to clear the chips, and it doesn't take very long at all to drill that hole.

    Once you've drilled the hole, you're essentially done, for all that remains to be done is to find a piece of pivot wire that fits that hole and jam it in: much of the time it'll hold there very nicely by friction, and if not you can use the tiniest drop of red Loctite.

    I'm not scared of re-pivoting any more, though I must admit I have not tried this trick with French clocks.

    M Kinsler
     
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