Balance staff size using a pivot gauge

Discussion in 'Watch Repair' started by darlek, Feb 18, 2014.

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

    darlek Registered User

    Apr 26, 2013
    68
    0
    6
    Really struggling to identify the size of what I think is a friction fit balance staff. The ID of the maker of this pocket watch is a real problem so I have pushed the staff out so I can measure as best as I can its dimensions. I was wondering if I can use a pivot gauge to help with its dimensions. I have been using a micrometer and the overall length is 4.893mm BUT both ends of this staff are broken so I guess its size should be 5.0mm+ the shoulder measures 2.132mm. I was hoping if not getting the exact balance staff but to purchase a staff that is too large and to make a fit using my lathe. I have been looking at the web site www.balancestaffs.com but I need more measurements. Any help will be most appreciated .


    Balance staff1.jpg Balance staff2.jpg Pocket watch (1).jpg
     
  2. DaveyG

    DaveyG Registered User

    Mar 21, 2005
    2,453
    103
    63
    Male
    Retired military aircraft engineer
    North Wales, UK
    Country Flag:
    Firstly, I don't think that a pivot gauge will help you a great deal as the measurements that you can take using a micrometer (or good quality digital caliper) are those that could possibly be taken with the aid of your pivot gauge. The hardest measurements to take (in my experience) are the length measurements not the those of diameter. I use a digital caliper and/or a depth gauge for those and take the measurements three times. The measurement of overall length is best done using a douzieme gauge or modern equivalent by removing both cap jewels, fitting the balance cock and measuring the outside distance between the hole jewels.

    Secondly, I'm not sure that the staff is a friction fit staff but if you have a lathe have you considered making the staff yourself?

    Finally, I'm afraid that I can't help with identification of the movement although it looks something like a Waltham Equity. I take it that there are no marks on the dial or on the pillar plate beneath the dial?
     
  3. Jim Haney

    Jim Haney Registered User
    NAWCC Member Donor

    Sep 21, 2002
    6,283
    851
    113
    Male
    Working the farm, Garden,horses, goats, chickens,
    Decatur, TN.
    Country Flag:
    Region Flag:
    darlek,

    I have moved your inquiry to the Watch Repair Forum for help.

    Davey has answered your question correctly but other may want to add to it.

    The pivots on balance staff are to small for the gauge you are trying to use.

    Balance pivots are usually measured in mm and fall in the .018-.010 range.


    Thanks
     
  4. 179

    179 Registered User
    NAWCC Member

    Sep 16, 2008
    526
    82
    28
    I have never seen a friction staff with that large of a hub. Friction hubs are riveted to the balance arm. Cannot help with the ID.
     
  5. doug sinclair

    doug sinclair Registered User

    Aug 27, 2000
    14,364
    50
    48
    Calgary, Alberta
    Country Flag:
    Region Flag:
    That is not a friction staff! If you drove the staff out of the balance, you may have done a number on the balance wheel. The gauge you show is one I have never seen used in watch repairing. I suspect you are way beyond your depth on this project!
     
  6. MrRoundel

    MrRoundel Registered User
    Donor

    Dec 28, 2010
    1,081
    91
    48
    So. Cal., USA
    Country Flag:
    Region Flag:
    In Henry Fried's "Watch Repairer's Manual", for length he adds .25mm for each broken pivot in a wrist-watch, and .30mm to each in a pocket watch. This should get you fairly close.
     
  7. darlek

    darlek Registered User

    Apr 26, 2013
    68
    0
    6
    Thanks Doug I think you are correct that I might well be out of my depth. However using the .30mm for the broken pivots and measuring many times I might have found the correct staff at www.balancestaffs.com. Also I think this is not a friction fit its just me being a new boy with this.
    I used a Bergeon Platax tool to remove the staff (after many practices with old staffs I bought on ebay) and there seems no damage to the balance.
     
  8. DaveyG

    DaveyG Registered User

    Mar 21, 2005
    2,453
    103
    63
    Male
    Retired military aircraft engineer
    North Wales, UK
    Country Flag:
    I have seen some cheap Swiss watches that have had friction fit staffs without a hub and this may be of that ilk (although it doesn't look Swiss to me). The ones that I have seen are not good and were only worth the trouble because I was able to buy a staff cheaply.

    Mr Roundel - with a staff, 'fairly close' isn't close enough IMHO. Why guess when you can measure :)
     
  9. bkerr

    bkerr Registered User
    NAWCC Member

    Nov 29, 2007
    1,280
    9
    38
    Male
    Sales & Marketing Manager
    Canal Fulton,OH
    Country Flag:
    Region Flag:
    This is what I use to measure staffs. It is a very nice tool to have in the arsenal.

    JKA measure tool.jpg
     
  10. WatchmakerWannaBe

    WatchmakerWannaBe Registered User

    May 25, 2013
    859
    2
    0
    Northern California, USA
    Country Flag:
    Region Flag:
    I 2nd bkerr's post! The Feintaster micrometer is a must have for staff measurements. It's relatively easy to use - a pleasure to use even. And it will give you true dimensions to within a few thousandths of a mm. I routinely check my Feintaster for accuracy using known plug gauges of various sizes.
     
  11. DaveyG

    DaveyG Registered User

    Mar 21, 2005
    2,453
    103
    63
    Male
    Retired military aircraft engineer
    North Wales, UK
    Country Flag:
    A fantastic tool for sure - if you can afford it!
     
  12. WatchmakerWannaBe

    WatchmakerWannaBe Registered User

    May 25, 2013
    859
    2
    0
    Northern California, USA
    Country Flag:
    Region Flag:
    #12 WatchmakerWannaBe, Feb 18, 2014
    Last edited: Feb 18, 2014
    True DaveyG.

    Although the prices for these tools (and a few other "must have" tools) seem to be going down lately - getting more and more affordable. Perhaps it's a sign of a declining global economy...I guess there's a silver lining to just about everything.

    There are other micrometers out there of course - like the Geneve type that measures in thousandths of a mm (instead of hundreths), but the jaws are not specifically made to hold irregular shapes like balance staffs...that and they don't seem to show up very often compared to the Feintaster.

    I wonder, does/did Glashutte make tools at one point? I've seen fantastic examples of their watchmaker's tools, but I've never seen any of their tools, for sale...at least not their micrometers.
     
  13. bkerr

    bkerr Registered User
    NAWCC Member

    Nov 29, 2007
    1,280
    9
    38
    Male
    Sales & Marketing Manager
    Canal Fulton,OH
    Country Flag:
    Region Flag:
    Tools that are for special use are always expensive. Look at some of the tools for a new car, 10K for a computer and without it you are stuck. I am lucky enough to have some special machinist tools as well. It really comes down to the old adage, you get what you pay for. I have invested in clock and watch tools over the years and there are some that I am still looking / saving for.

    Here are a couple that I no longer use. bergeon mic.jpg watchcraft measure.jpg
     
  14. WatchmakerWannaBe

    WatchmakerWannaBe Registered User

    May 25, 2013
    859
    2
    0
    Northern California, USA
    Country Flag:
    Region Flag:
    Neat stuff bkerr.

    I've started gathering the tools in lieu of watches - as a means to aid in affording them. And it is absolutely worth it. There are those who say that it's not the tools that make the watchmaker. And that might be true. But for beginners like me, the right tools make all the difference in the end results.
     
  15. MrRoundel

    MrRoundel Registered User
    Donor

    Dec 28, 2010
    1,081
    91
    48
    So. Cal., USA
    Country Flag:
    Region Flag:
    Fried must have had his reasons for including these "estimators" in his book. However, I'm sure that he'd agree that eliminating guesswork is a very good idea, if you have a way around it. Fried also provided the proper way to measure for a staff that's totally missing, or completely FUBAR. (My term, not Fried's. ;) )

    That said, if you get pretty close with an length estimate, I'd think that you'd have a shot at looking at either the Bestfit Master Staff System or Townsend's "American Pocket and Wrist Watch Balance Staff Interchangeability List", to compare approximated length, along with other more exact measurements, and come up with a good, perhaps adjustable prospect.
     
  16. DaveyG

    DaveyG Registered User

    Mar 21, 2005
    2,453
    103
    63
    Male
    Retired military aircraft engineer
    North Wales, UK
    Country Flag:
    I enjoy my tools as well folks and I have (quite literally) a shed load of them. I would hazard a guess though, that the market in the USA is a tad different to here in the UK; whenever I have seen these, usually at auction, they have fetched sums in hundreds of pounds. Supply and demand?

    I too have seen Fried's estimates as to pivot length and have always wondered why you would need to know that, unless you are planning on re-pivoting. The real question for me about guesstimations on overall length is - what do you do if you guess too short? The douzieme style gauges are readily available second hand and you can still buy them new. My old one cost me nothing, measures to 0.1mm and, although a bit tricky to use until you get the hang of it, provides a far better basis for alternative selection or even making a staff from scratch. The more modern dial indicator types are surely much better but - more expensive so you have to do the cost/benefit thing
     
  17. RJSoftware

    RJSoftware Registered User

    Apr 15, 2005
    8,273
    68
    48
    Male
    Loxahatchee, Florida
    Country Flag:
    Region Flag:
    #17 RJSoftware, Feb 19, 2014
    Last edited: Feb 19, 2014
    A few tools to mention here.

    A binocular microscope. They come in stereo and mono. They give working distance so a person can use tools on object while viewing.

    A graticule/reticule/reticle lens. This lens is flat glass that fits in microscope eyepiece and gives any microscope the added ability to compare objects by size. The reticule lines are faint, but you get used to it.

    A microscope objective stage. Although it may work, one has to lay a staff on top which would be slightly angled. Not as good as a reticule.

    A set of small wire gauges. Small sets can be found that start off as small as .07mm. They can be used to measure lengths by laying a wire across perpendicular and eye-ing under the scope to compare width of wire against length of some section of a pivot. You can butt the end of the wire against a length under the scope to be most accurate. Choosing the correct mm.

    Another set of gauges is the Pivot gauge set. This is NOT the flat metal object with the V slot. Those are terrible. The pivot gauge set goes much smaller than the above mentioned and are specific to watch makers. You put them in the jewel hole and test how far they lean (or not lean) in the pivot hole. Anyone with a lathe should make themselves a set. Otherwise it's trial and error. Yes, I still need to make mine.

    Without the small pivot gauges it's trial and error. You cut and test, cut and test, cut and test and cross your fingers you don't cut too much.

    Measuring a staff length is not bad. You may need to get all the measures one day, so why not give it a try now. Since you need to know.

    With your best micrometer, one that has no play, measure with balance cock installed and dial off across upper and lower balance jewels. Remove one of those jewel caps (end stones) and measure it's thickness. Subtract the cap thickness x 2 from previous length and you have staff length.

    A needle will help with next steps.

    With a needle, stick a small piece of paper or small piece of WD40 red straw on needle. This will work as a sliding gauge. We will call the paper/straw the indicator.

    Stick needle down near fork of lever and adjust the height of the indicator with tweezers so you have the height of the lever or if you like the finger.

    This will be the distance from the pivot cone to where the roller table should land.

    Next is the balance hub. Place needle next to minute wheel and adjust indicator so you have the distance so the balance wheel will clear the minute wheel. So you subtract balance wheel thickness from that and don't worry about the extra pivot distance as a little extra clearance is good.

    The hairspring is nothing. You begin by tapering and testing the hs collet to see if it will fit. Under the scope, when you see the collet beginning to slide on, that is your thickness, so cut rest parallel to that. However, be warned it's easy to go to thin. So save some thickness for fine polishing.

    Then all you got left is your thickness's and your roller taper and your done. The roller taper is not as picky to me as the hs diameter. The taper is often more thin than I anticipate. Cutting a straight line from thin to thick (next to hub) is easy. You cut one, then the other and make a straight line. Then keep working that and test, cut, test, cut...

    See, you could do the above steps if you know the length on an already pivoted staff.

    But you will need tools. Most of all the binocular microscope.

    RJ
     
  18. MrRoundel

    MrRoundel Registered User
    Donor

    Dec 28, 2010
    1,081
    91
    48
    So. Cal., USA
    Country Flag:
    Region Flag:
    Excellent, thanks for posting these techniques. I'll spend some time with them tomorrow. Cheers.
     
  19. Kevin Scott

    Kevin Scott Registered User

    Aug 2, 2011
    570
    5
    0
    Country Flag:
    I believe in the value of good measuring tools, and prefer to finish to size without trial fitting, or a minimum of trial fitting on the staff diameters.

    But when it comes to overall staff length, I think it is close to impossible to be exact when the old staff is missing or has a broken pivot.
    I have a JKA dial micrometer, but do not like it for measuring the overall staff length. Also have a very high quality swiss vertical micrometer that uses changeable anvils to measure between the jewels, or to measure staff length. The vertical micrometer seems the best way for staff lengths.

    But no matter how careful you are, in the end you are going to have to final fit the staff length. Unless you are dealing with a watch that allows for alot of endshake like some American PW.

    I have at least 5 books showing staff dimensions. Never do they all come up with the same measurements for a particular staff. And the biggest variation is in the overall staff length. This tells me I am not the only one that has problems coming up with a definitive staff length by measuring alone.

    Seems to me it is best to get "fairly close" and a bit on the long side when it comes to staff length. Then make a final adjustment to the length after fitting. I have not reviewed my books, but doubt if any suggest that a final check or fitting is not needed for staff length and endshake.
     
  20. RJSoftware

    RJSoftware Registered User

    Apr 15, 2005
    8,273
    68
    48
    Male
    Loxahatchee, Florida
    Country Flag:
    Region Flag:
    #20 RJSoftware, Feb 21, 2014
    Last edited: Feb 21, 2014
    >>I believe in the value of good measuring tools, and prefer to finish to size without trial fitting, or a minimum of trial fitting on the staff diameters.

    Yes, when I think about how much time I could have saved myself by either buying or making a pivot gauge set, instead of trial and error I feel guilt because it is my sheer lack of dedication from lazy-ness.

    >>But when it comes to overall staff length, I think it is close to impossible to be exact when the old staff is missing or has a broken pivot.

    Yes, this is a pain to me. I add extra length and try to reduce a little at a time. I am always slightly disappointed because I almost feel like I blindly did it. Like I don't have the routine down pat and I am guessing instead of that good feeling you get when you know you are precise. I suppose cap jewels can vary in depth even though there are shoulders for them. So maybe they can sit different... I don't know. Just guessing.

    It just seems so junky monkey make it do. I think it's the slack of even my finest micrometer and the inability to reliably transfer that measure with that precision feel. I'm pretty sure I just need a fientaster (like WMWB(is) has).


    >>I have a JKA dial micrometer, but do not like it for measuring the overall staff length.

    Lol. Yes we are in 100% agreement.

    >>Also have a very high quality swiss vertical micrometer that uses changeable anvils to measure between the jewels, or to measure staff length. The vertical micrometer seems the best way for staff lengths.

    Sounds good.

    >>But no matter how careful you are, in the end you are going to have to final fit the staff length. Unless you are dealing with a watch that allows for alot of endshake like some American PW.

    I forget who, but either Fried or De Carle talks about "perceivable" lengths. So things like how much a balance can be wiggled when installed is a bit ambiguous. But I guess better than nothing.

    >>I have at least 5 books showing staff dimensions. Never do they all come up with the same measurements for a particular staff. And the biggest variation is in the overall staff length. This tells me I am not the only one that has problems coming up with a definitive staff length by measuring alone.

    One of the letdowns about this was that "American staff interchangeability" book. I don't mean to put it down because I am sure it is useful. But I was hoping to avoid always making a staff. Thing is where I messed up is I purchased staffs out of the movements. So, try to one by one take measure of each staff, knowing that there are descrepencies in lengths and sort out candidates and then one by one go over each attribute till you get the best match that needs to be trimmed. By the time I do all that I could have just simply cut a new one and be done. This is also because I lack in organization. If I had a better system of organizing them, I ... well, I am not a business of it yet.

    >>Seems to me it is best to get "fairly close" and a bit on the long side when it comes to staff length. Then make a final adjustment to the length after fitting. I have not reviewed my books, but doubt if any suggest that a final check or fitting is not needed for staff length and endshake.

    You know, I have yet to accomplish a good enough fit to do the 1/2 banking thing. (where balance spins back and forth without hairspring, bouncing off banking pins). But it seems like even though I have never accomplished that (I keep trying :) ) the watches still run in good time.

    It's the length thing. With diameter, I get good lean, not too much, not too little. So I am happy with pivot diameter. I think what has been happening is when I reduce length, I wind up with cone rubbing jewel. I know Fried goes over this explaining that when you reduce cylinder length you also need to cut back the cone. But this is not a clear cut as that.

    I think this is where not turning by centers fails me. It's too easy just to collet up, so I need to force myself to "turn by centers" each time I do a staff. When I collet up, not having a complete set, I sometimes have to fudge a bit. So a re-install junks the accuracy every time. Especially when I try to collet up the taper side.

    I'm not really 100% happy. I know that feeling when I do a job right. I really just don't have it yet. Some bad habits I have to break.
     
  21. Kevin Scott

    Kevin Scott Registered User

    Aug 2, 2011
    570
    5
    0
    Country Flag:
    RJ, to be clearer, the JKA dial micrometer I referred to is signed Fienstaster, and is the same as WMWTB's. It is the common boxed micrometer that many people use. Have had one since 1992, and use it regularly. But do not like the spring loaded feature for staff lengths. Mostly use a regular mm micrometer measure a staff.

    If you have a large assortment of unlabeled staffs, when looking for one sort them out by length. I set up a couple micrometers and use them as go no gauges. Then refine them again next time you need a staff. So the first time you might have two piles, over 5.00mm and under 5.00mm. So next time you need a staff 4.10mm you sort out the under 5.00mm pile into two piles, under 4.00mm and over 4.00mm. After a while you have them pretty well sorted out by length. I do end up saving time by finding a close staff to modify using staff assortments.

    One issue than your measuring system for measuring the distance between the hole jewels does not take into account is the space between the cap and hole jewel. There must be some space to hold oil. So your measurement for how long the staff should be will often come up a little short.
     
  22. MrRoundel

    MrRoundel Registered User
    Donor

    Dec 28, 2010
    1,081
    91
    48
    So. Cal., USA
    Country Flag:
    Region Flag:
    FWIW: The Bulova School of Watchmaking course book shows the space you are referring to (between cap and hole jewels) is .02mm. Of course I do not know how much actual measurement will deviate.
     
  23. DaveyG

    DaveyG Registered User

    Mar 21, 2005
    2,453
    103
    63
    Male
    Retired military aircraft engineer
    North Wales, UK
    Country Flag:
    Accepting that figure, and it is probably a wee bit more on a pocket watch, if you measure up between the hole jewels then you will have adequate up/down or end shake (whatever you want to call it).
     
  24. RJSoftware

    RJSoftware Registered User

    Apr 15, 2005
    8,273
    68
    48
    Male
    Loxahatchee, Florida
    Country Flag:
    Region Flag:
    Ok, I see we have two different methods of measuring staff length.

    I measure from fully installed cap jewel to installed cap jewel. Then I subtract 2x cap jewel thickness.

    I can see where you would think that mine come up short not accounting for oil space of .02mm.

    If your measuring across top of one hole jewel to the other, but that does not make sense as pivot lengths vary...

    No, I think the proper way is to use both outer surfaces of the cap jewels. Then subtract cap jewel thickness x 2.

    But I realize that it has to have play. So rounding pivot ends with stone should do it.

    If that measure is wrong it's probably error in transferring the measure to the stock.

    I use a regular micrometer and it's twisting action screws with staff length measure. I have even ground tweezer specific to hold a staff firmly in a groove so the twisting action of the micrometer would not accidentally measure staff at angle. Hard to hold it perfectly and get a good measure. Go and no go.
     
  25. Fred Coulson

    Fred Coulson New Member

    Nov 15, 2018
    3
    0
    1
    Male
    Country Flag:
    #25 Fred Coulson, Jan 3, 2019
    Last edited: Jan 3, 2019
    you can buy one of theses and make your own ends for measuring most pivots I think it came from bangoods cheap. ebay
    Portable Digital Thickness Gauge Meter Metal Tester Micrometer 0 to 12.7mm H0A4

    P1020952.JPG P1020953.JPG P1020954.JPG
     

Share This Page