American PW Watch Balance Repivoting

Discussion in 'Watch Repair' started by Andy Dervan, May 19, 2020.

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  1. Andy Dervan

    Andy Dervan Registered User
    Gibbs Literary Award NAWCC Star Fellow NAWCC Member

    Oct 23, 2002
    2,513
    63
    48
    Male
    Country Flag:
    Region Flag:
    Hello All,

    In the March/April 2020 Watch and Clock Bulletin Mahlon Shetler and I co-authored an article titled "Minimally Invasive Watch Repivoting". We outlined the technique Mahlon has developed to simply and safety repivot pocket and wrist watch balances that he has been doing routinely since 2013.

    Mahlon asked me to poll Message Board Repairers for their comments about the article and the technique.

    I am curious how many repairers actually to watch repivoting?

    Andy Dervan

     
    Paul Raposo and gmorse like this.
  2. gmorse

    gmorse Registered User
    NAWCC Member

    Jan 7, 2011
    11,285
    1,583
    113
    Male
    Retired from Xerox
    Breamore, Hampshire, UK
    Country Flag:
    Region Flag:
    Hi Andy,

    I'm surprised that you haven't had more responses to this, I found Mahlon's technique fascinating and most impressive. I particularly like his use of a sapphire wheel to give the final finish. I do undertake re-pivoting where necessary, but not on balance staffs. This is partly due to the majority of my work being on watches which pre-date the adoption of the lever, and verge staffs are not so conducive to this approach; I'm sure it would be possible to use it on the lower pivots, with care, but getting the very thin staffs to run true is one problem.

    Regards,

    Graham
     
  3. Skutt50

    Skutt50 Registered User

    Mar 14, 2008
    3,556
    125
    63
    Male
    Gothenburg
    Country Flag:
    I have not read the article but I do occational re-pivoting. Very seldom on balance staffs but often on fourth wheel when the seconds hand pivot has been broken or the center wheel when the post for the canon pinion is gone......

    As I said, seldom balance staffs since I often can find a replacement or modify one that is close in dimmensions......
     
  4. Andy Dervan

    Andy Dervan Registered User
    Gibbs Literary Award NAWCC Star Fellow NAWCC Member

    Oct 23, 2002
    2,513
    63
    48
    Male
    Country Flag:
    Region Flag:
    Hello Skutt50,

    Balance staffs are getting harder and harder to find and the punching them out improperly can result in damage to the balance.

    Mahlon's technique is much less invasive to the balance and he does a lot of swiss ladies watches that balances are difficult to find.

    Andy Dervan
     
  5. DeweyC

    DeweyC Registered User
    NAWCC Member

    Feb 5, 2007
    2,132
    771
    113
    Watchmaker
    Baltimore
    Country Flag:
    Andy,

    Thank you for bringing this to my attention. I love seeing other ways to skin the cat!

    It is well written and the photos are very clear. He is obviously one of the first class mechanics and someone who thinks.

    Without a doubt, this article was much better than many articles I have seen in the AWI HT. It really was first class and I highly recommend people read it no matter how experienced they are.

    What you are doing is important work. Keep it up.

    As you may know, I do a lot of small repivoting and have used carbide drills since returning from Switzerland in 2010. Not a brag, or "look at me" declaration, just to put my comments in context.

    As Mahlon will agree, you must have a factory matched head and tailstock and excellent collets.

    The microscope is also essential. Only very young and macho watchmakers do this work with a 10x loupe and their nose in the way. Would have been illustrative to show a view as seen through an eyepiece even if just a camera shot through the eyepiece. This is kind of fiddlely, but can be done with a cell phone or pocket camera (I learned this from a student).

    It looks like Mahlon found that with a carbide spade drill (stiffest design) there is no need to cut a female center? Is it likely a worker who has not mastered female centers is able to make the required grinding jig and make accurate carbide drills? ( editorially: any drill with uneven edges will cut oversize)

    While I do make my carbide cutters with an Agathon grinder (alternatively a Deckel/Alexander SO grinder), I do not make the drill bits. I buy them.

    Measurement is key. I am not looking to make work for you two, but given your writing skill, an article discussing various techniques to obtain the required measurements and how to work to them would likely be much appreciated by learners.

    Fact Is, I hope that Mahlon and I can meet in a shop sometime and spend a day and have lunch. I never did learn anything from someone who did things just like me. I love it!
     
    Rafa G and gmorse like this.
  6. Skutt50

    Skutt50 Registered User

    Mar 14, 2008
    3,556
    125
    63
    Male
    Gothenburg
    Country Flag:
    Since I don't have access to the article I can't comment on it. I only answered your question on repivoting practise.

    I use my lathe to remove a balance. No punching needed.....

    If I can't find a suitable staff to work with I can cut a new. Fortunately I don't have to do that very often.....
     
    Randy Beamer likes this.
  7. f.webster

    f.webster Registered User
    NAWCC Fellow NAWCC Member

    Dec 18, 2009
    771
    26
    28
    Male
    Service/Restoration of Clocks and Mechanical Music
    Louisville, KY
    Country Flag:
    Region Flag:
    I read the article. Being new to watch repair I found it very interesting. I thought that the process detailed WAS the way that things were done.
     
  8. Andy Dervan

    Andy Dervan Registered User
    Gibbs Literary Award NAWCC Star Fellow NAWCC Member

    Oct 23, 2002
    2,513
    63
    48
    Male
    Country Flag:
    Region Flag:
    Dewey and Frank,

    Thank you for your comments...

    Andy
     
  9. Jerry Kieffer

    Jerry Kieffer Registered User
    NAWCC Member

    May 31, 2005
    2,626
    341
    83
    Male
    wisconsin
    Country Flag:
    Andy
    Will answer your last question first.

    While there are exceptions and its no issue, I personally seldom repivot a balance staff. The main reason being that I dimensionally machine replacement staffs in the same manner almost all are originally machined. Since diameters and lengths are precisely mechanically controlled, this eliminates the tedious job of continuous measurement and fitting. In fact the actual machining of the part is never observed, only the movement and settings of calibrated hand wheels under a Loupe configured for 5"-6" working distance. While there is nothing wrong with a professional repivoting, the efficiency of staff machining makes it less attractive for myself. I suspect that machining a staff is seldom if ever utilized in horology, in that it has never been practical with any of my half dozed or so watchmakers lathes and slides.

    I recently had a chance to watch a young Amish watch maker perform this repivoting procedure. It is so refreshing to finally see some original thought and acceptance of demonstrated efficiency as well as their eagerness to see demonstrations by others. On forums, if you challenge a tired high skill procedure, you can only wait for the next melt down.

    If someone wishes to try this method and by chance did not want to make your own drill, carbide drills are readily available designed for both the material being drilled and the depth to be drilled. Depth of drilling is designed by "Diameter times length" . Another words, a drill designated as a "D4" would have flute length of 4 times that of the drill diameter. Such drills are readily available from larger machine tool supply houses by listing or request.

    For the type of work being discussed, lathe alignment must be perfection to protect any drill. The alignment required is seldom available from any lathe even with the original tailstock other than a half million dollar machining center. As mentioned in the article, its possible to shim and modify tailstocks, but requires a lot of patients and skill. One simple method of creating perfection, is to drill/ream stock held in the tailstock to a slip fit to the drill arbor.

    Thanks for publishing an excellent article.

    Jerry Kieffer
     
  10. Chris Radek

    Chris Radek Registered User
    NAWCC Member

    Apr 13, 2014
    574
    190
    43
    Male
    Watchmaker (now accepting new customers)
    Lincoln, NE, USA
    Country Flag:
    Thanks for asking here. What a great article. My random thoughts:

    Before reading this article my opinion was that it's worth the trouble repivoting things with pinions, as I have done on all sizes of work down to wristwatches. I did not consider it worth the trouble to repivot anything that can be simply remade in one piece, such as balance staffs and unthreaded pallet arbors.

    After reading your article I think I might have been wrong. It's hard to argue with your results in figure 10. You also make a strong case, and I agree, that you WILL not affect the adjustment of the watch using your technique. With proper care when restaffing with a riveted staff, you can only say that if everything goes well you MAY not affect it. That is a strong argument. (I am still not convinced a friction staff like the 992B in the article should be repivoted, but I understand you did it as an example.)

    I am curious about the sapphire wheel. I have a handheld sapphire "burnisher" (I'm not sure it actually burnishes) but had never considered using one in wheel form. I'm curious about that now but after some google searching I don't immediately see where I can get one like the one you show.

    I wish the article had specified which Loctite product you're using, as there are about a hundred of them. I use 648, cured slightly warm (over an incandescent bulb), when repivoting. It's on the thicker side, which helps apply it I think.

    Like Dewey, I have had so much success with PCB carbide drills that I'm not tempted to try making my own, but I appreciate you writing up the technique anyway.
     
  11. Andy Dervan

    Andy Dervan Registered User
    Gibbs Literary Award NAWCC Star Fellow NAWCC Member

    Oct 23, 2002
    2,513
    63
    48
    Male
    Country Flag:
    Region Flag:
    Thank you the comments.

    We have received inquiries where to acquire tooling and supplies for this repivoting procedure, so we created this list.

    Andy Dervan
     

    Attached Files:

    Randy Beamer likes this.
  12. Al J

    Al J Registered User

    Jul 21, 2009
    594
    69
    28
    Agreed - I never punch out staffs. They are either cut out on the lathe, or dissolved using alum where possible. The latter is the technique I use most often these days.

    Cheers, Al
     
  13. gmorse

    gmorse Registered User
    NAWCC Member

    Jan 7, 2011
    11,285
    1,583
    113
    Male
    Retired from Xerox
    Breamore, Hampshire, UK
    Country Flag:
    Region Flag:
    Hi Frank,

    It's one way of doing it, and in the hands of a master like Mahlon, it appears so easy, but I believe that most people would choose to cut a new staff in the absence of the correct original part, with the practical caveats mentioned earlier about avoiding any damage to the balance in the process of removing the broken staff.

    Regards,

    Graham
     
  14. Chris Radek

    Chris Radek Registered User
    NAWCC Member

    Apr 13, 2014
    574
    190
    43
    Male
    Watchmaker (now accepting new customers)
    Lincoln, NE, USA
    Country Flag:
    Thank you for the extra information! It's just a sapphire watch crystal!
     
  15. Jerry Kieffer

    Jerry Kieffer Registered User
    NAWCC Member

    May 31, 2005
    2,626
    341
    83
    Male
    wisconsin
    Country Flag:
    #15 Jerry Kieffer, May 21, 2020
    Last edited: May 21, 2020
    Andy
    Thanks again for the tool list.

    In your first post you requested comments on technique etc.

    While repivoting has been around for several hundred years, this is unique in the sense that few watchmakers repivot balance staffs. Again, while all repivoting is basically the same procedure, original thought as in this case is always interesting. However, with many suggested horological procedures, it is a very high skill procedure as presented. Again, it is certainly not an issue once mastered and practiced on a daily basis. Unfortunately, when I stand in front of a class, beginning students are really only interested in what they can accomplish today, not ten years from today. Some do not have ten years.

    In most cases, much metal working skill can be replaced by utilizing basic metal working machining practices with this procedure being no exception.

    On this forum, it has been suggested that my interest in model engineering would some how effect my ability to handle watch parts when quite the opposite is true. Exact scale model engineering involves the design, function and construction of a devise despite the laws of physics. Part sizes can be a fraction of watch parts such as the scale .007" x 420 TPI hex bolts and nuts requiring tap/die construction in the first attached photo. Sorry about the quick photo quality. The point of this is that if high skill procedures must be mastered for each procedure, little can be accomplished in a life time. Metal working in Horological repair is much easier in that you simply have to copy an existing part. When you couple that with the use of basic metal working practices, beginning students can often master what may seem impossible on their first attempt. The following is a couple of examples covered in repivoting during the NAWCC WS-117 workshops.

    (1) While making your own .18mm carbide drill is not an issue for some, but is not a skill most watchmakers will ever master. Nor do they need to, since carbide drills are readily available designed for the material drilled and the depth drilled. Second photo example of a 3D drill per post #9.

    (2) Once a hole is drilled, friction fitting tempered stock to a .18mm hole is something that must be attempted to be understood. Of course, anyone can shove a tapered pin in a hole but in this case it would not lead to an except-able outcome. Almost all skill can be eliminated by reaming a desired friction fit hole for the stock purchased. For example, .23mm stock as mentioned is not perfectly round and has a average size of about .0091" By reaming the hole with a .009" reamer, functional friction fitting of the stock is assured each and every time with no fitting, skill or chemicals required.

    (3) Cementing the sapphire crystal to a arbor is not an issue, but again requires experimental and developed manipulation skills. While getting the crystal to run true while spinning is of no issue, having it cure in that position is an issue. Epoxy , before it sets becomes a rubbery type consistency and wants to return to its original position while curing. You can tell me that it will remain in a position of perfection while curing, but it would be another thing to demonstrate it. The skills involved can again be eliminated with basic machining practices per the third attach sketch.
    With a arbor in a accurate collet, you can bore a pocket per the sketch that the crystal will just fit into. This will hold the crystal to perfection minus lathe bearing runout while the epoxy dries. Once dry, machine off the outer ring at the desired location.

    I have had a fair number of students who are intimidated by suggested high skill methods to the point of loosing all interest. (The last thing we need) My goal, is to provide options that will allow for high quality work on their first or second attempt or at least in a very short time.

    Jerry Kieffer

    fullsizeoutput_5d5.jpeg fullsizeoutput_5ce.jpeg fullsizeoutput_5d6.jpeg
     
    Old Rivers likes this.
  16. DeweyC

    DeweyC Registered User
    NAWCC Member

    Feb 5, 2007
    2,132
    771
    113
    Watchmaker
    Baltimore
    Country Flag:
    Jerry,

    Sounds like you should submit an article!
     
  17. Jerry Kieffer

    Jerry Kieffer Registered User
    NAWCC Member

    May 31, 2005
    2,626
    341
    83
    Male
    wisconsin
    Country Flag:
    #17 Jerry Kieffer, May 21, 2020
    Last edited: May 21, 2020
    Dewey
    Actually, I have had many Micro machining/fabrication articles published over the years, but they are of course copyrighted by the publisher. The most popular seems to have been the "Construction of miniature taps and dies" such as those mentioned in post#15. It was published in the Jan-Feb 2008 issue of the Homeshop machinist. Copies are sometimes available from the publisher and or E-Bay.
    The Home Shop Machinist Jan/Feb 2008 Making Miniature Taps and Dies | eBay

    Currently, The Craftsmanship Museum is putting together the story and construction details/procedures of my second bar stock watch movement. It should go online sometime later this year depending on the virus delays. It will also cover Micro machining procedures.

    What I have found over the years is that those truly interested want to experience procedures by their own hands. Repivoting procedures as mentioned are covered in workshop WS-117. Again depending on the Virus, It will probably be held in Vista California sometime in November this year. Anyone interested can contact Gillian at the main office in Columbia.

    Jerry Kieffer
     
  18. DeweyC

    DeweyC Registered User
    NAWCC Member

    Feb 5, 2007
    2,132
    771
    113
    Watchmaker
    Baltimore
    Country Flag:
    I am sure Jerry. But it sounds like you have an article for the NAWCC!
     
  19. Dr. Jon

    Dr. Jon Moderator
    NAWCC Member

    Dec 14, 2001
    5,754
    484
    83
    Aerospace Engineer
    New Hampshire
    Country Flag:
    Region Flag:
    I found the article very useful, especially on making the drill bits.

    I make my own using a Chinese copy of the Deckel grinder. The one Shars sells seems free of the nightmares described in many posts about these copies. I had abandoned the hope of making fine drills. I found that I can make 1/8"'s spade drills that will usually catch a center if the area is not badly garfed and that a printed circuit drill will then follow that center.

    Since reading the article I revisited making finder drills. I now use a microscope for the final finish and I can get to better than 0.2mm.

    One thing the article did not mention is that it is good idea to check the run out on the drills. My grinder had serious run out until I cleaned the work holder. The produced run out in the drills I roughed ground. By rough I mean I take off most of the carbide using a 1500 grit wheel. I then finish it similarly to what the article suggested.

    Now I routinely check run-out before rough grinding and and on the drill point. The grinder is a holder for dressing tool. I mount a dial gauge there instead for making drills.
     

Share This Page