Chronometry: Stand-in tool suggestion for removing helical spring on Hamilton model 21?

Discussion in 'Chronometers' started by MrRoundel, Mar 16, 2016.

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  1. MrRoundel

    MrRoundel Registered User
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    Greetings, gentlemen (and perhaps one or two ladies?),

    Recently I discovered that one of the pivots broke off of the balance staff on my model 21 chronometer. I'd like to replace it myself, and do have a fair amount of experience on replacing staffs in pocket watches. Since I paid around $400 for it to serviced about 15 years ago now, and don't want to duplicate that bill if I can avoid it, I'm going to attempt the repair myself. I am of course, proceeding slowly and cautiously, as I don't want to damage the nice chronometer movement.

    I don't plan on doing a complete service on the clock, so I won't be taking it down all the way. Instead, I figured I'd just replace the staff and see how she runs. After all, it was serviced professionally 15 years ago, and hasn't seen a lot of running time, maybe 30 days total. Surely the modern oils used, etc., should still be holding up, no?

    I may also have to replace the impulse jewel, as it look like it has a chip out of the center. This may be why I'm seeing a black fuzzy substance on the escape wheel teeth. I'm just guessing. Maybe I'll even need to replace the escape wheel because of this? I'm sure that if I paid a professional, the cost would be somewhere around $700. It's a nice timepiece, but I really don't love it that much.

    Right now I'm stuck on removing the hairspring. The manual calls for a "wedge tool" of some sort, but a screwdriver doesn't seem to be of much help. Does anyone know of a decent stand-in for the proper Hamilton tool?

    Thanks for any help, guidance, suggestions, warnings, etc. Cheers.
     
  2. doug sinclair

    doug sinclair Registered User
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    I replaced a balance staff on a model 21 many years ago. I don't have any of the special tools listed in the model 21 repair manual. Including the "wedge" you refer to. I will say that having a full kit of tools as is shown in the repair manual would be essential if one were to be doing the types and extent of servicing of these that was done back in the day. But I regularly strip the model 21 for routine servicing and maintenance, and it is possible to do this with conventional tools, knowledge of the model 21, the manual, and care. As to a "wedge", I would suggest using a piece of brass wire of a gauge that won't bend easily, and filing the tip to a long wedge that is slightly thicker than the broach in the hairspring stud. Pressing the wedge into the slot should open the hub sufficiently to loosen it, and the brass wedge should hold the collet long enough for you to lift it off. The mechanics of replacing the staff shouldn't be all that tough! The tricky part is getting the impulse jewel roller, the bypass jewel roller, and the hairspring back on in the proper place. The impulse jewel should be available. As to the escape wheel teeth, you need to take a very close look at those teeth under magnification. Do you have the repair manual for the 21? While you are at it, you should check the detent jewel for damage, as well. These are also available. If you are planning on returning the chronometer to service, you might just consider the fact that it has been (by your own admission) 15 years since it was serviced! You have a LOT of faith on the staying power of the lubricant used at that time! If it was my chronometer, I would service it before pressing it back into service. I am presently not running my 21, and it was serviced last ~ 5 years ago or so. Before I return it to service, I'll do it again.
     
  3. MrRoundel

    MrRoundel Registered User
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    #3 MrRoundel, Mar 16, 2016
    Last edited: Mar 16, 2016
    Thanks, Doug. The brass wedgie tool sounds like a good idea, as it's less likely to leave scars, right?

    Yes, I do have the Hamilton model 21 service manual.

    No, it won't be put into service. I only want to have it in running condition in the event that I sell it. Life is such that I just don't have the place to display it and enjoy it these days. Plus, it laying around, even though it was in the padded aluminum container, still somehow found the balance pivot breaking. I have suspicions, but that's all they'll ever be.

    I've been trying to put together quite a few watches that have been apart for too long. Otherwise, they'll soon end up as parts, and they're better than that. So I'm just replacing staffs, replacing mainsprings, etc., in those watches. Having "completed" most of them, I'm now looking at other "loose ends" that should be tied up before it's too late for them. Things get lost, broken, etc., right?

    Watches that have problems that are too deep for my limited skill, will just be assembled as much as practicable, and probably sold to someone who has the skills and desire to get them up and running again. I'm probably being too sensitive to preserving the watches I have as close to intact as possible. Then again, that's how most around here roll/tick.

    Many thanks for your learned input and advice. I appreciate it immensely. Cheers.

    Hey, I just figured it was serviced around the time that BMW started with "Lifetime" fluids in their cars.Nutjob So why not in watches? :cool:
     
  4. richiec

    richiec Registered User
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    Depends on whose lifetime, the lifetime of a fly, yeah that is possible, 2-3 days. Good luck on your project.
     
  5. Dr. Jon

    Dr. Jon Registered User
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    I suggest that you try to re-pivot it. That saves a lot of the original and assures the collet and roller fit well.
    There is a long description of how the Naval Observatory did this in marine chronometers in Marvin Whitney's book.
     
  6. MrRoundel

    MrRoundel Registered User
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    Thanks, Dr. Jon. That is still a possibility, as I haven't dug my deeper hole yet. Cheers.



    The worst things to happen to pocket watches over the years are the high price of gold, and the low price of screwdrivers.
     
  7. DeweyC

    DeweyC Registered User

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    I hesitate to respond to this because this is my bread and butter. But...

    Given our discussion on watch repair, are you sure you can tackle this? It is very easy to take a simple issue and turn it into a far more expensive repair.

    First, how did the pivot break? Was the instrument allowed to run out of power? Or, did it wear and finally snap from lack of lubrication? if the latter, the whole thing needs to be serviced.

    Why repivot when replacement balance staffs are available and inexpensive? Do you know how to reset the escapement once you take it apart?

    You ask how to remove the balance spring. Are you going to be able to remove the rollers without cracking the roller or damaging the impulse jewel? Reinstall them?

    As Karl said in another thread in repairs, sometimes it is better to put something aside until you have acquired the knowledge and skill.

    I am not looking for work BTW. I will be shutting down for the summer in May and have stopped taking things in until the fall. Just saying.
     
  8. MrRoundel

    MrRoundel Registered User
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    Thanks, Dewey. I get your, and the points, of others. The chronometer has sat with the balance removed for months now, and will probably stay that way. Ultimately, I'll probably pay to have a professional fix it to get it in running sale condition, or put it together and sell it as a fixer, which is most likely. Fixing it myself does sound a bit daunting, despite spending some time studying things.

    I know that chronometers are your bread and butter. You serviced this one back around 2000 or so. Time flies. Well, I guess when it comes to this model 21, time has landed for a while. It's just not worth it to me to pay the going rates to fix the chronometer. Not that I don't understand the work goes into it, it's just that it's not worth it to me. Maybe someday down the line. If not, I'll sell it before I ruin it.

    How the pivot broke is a mystery. I had it in storage for a few years, but it was running when liberated from the storage unit. I only ran it a few times after that, before I put the movement in the aluminum shipping container. When I took it out last year, it didn't run. I was surprised. When I checked the balance, it was obvious that a pivot was gone. Prime suspect, if it was a person, is that the house-cleaner that comes here now and then knocked the container down from about a 20" height. If that happened, it would have been without spring power at the time. Regardless, it is a bit of a sad mystery. Oh well...

    I don't want to be the "screwdriver guy" in my new signature. Thanks again for your input. Cheers.


    The two worst things to happen to pocket watches over the years are the high price of gold, and the low price of screwdrivers.
     
  9. DeweyC

    DeweyC Registered User

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    I was worried my note would not be received in the manner intended. Sigh of relief.

    OK. 15 years. Lubrication failure. The balance ran its pivot down.

    I am a sample of one; there is not a community of chronometer makers these days and it is not like the 1900's when there were 1000's of chronometers in service. So what I am suggesting is really no more than opinion.

    I think the old organic oils had their drawbacks, but they also had a safety feature. When they dried out they would grab and seize pivots; may result in scratches, but it would stop the instrument before it self destructed. Kind of like high grade French clocks, unless everything is perfect the pitch is so fine they refuse to destroy themselves.

    Modern oils in a sealed watch case have a service life of 5 years. When they dry out, they leave no real solids behind. So the piece continues to run without a protective barrier and nothing to stop it. Another 10 years and and something is worn to a critical point.

    In deck watches and chronometers, the mass of the balance to the pivot size is extremely high and lubrication is far more critical than in WW.

    Anyway, my thought. Remember, in service navigational timepieces were serviced every 3 years. While a home environment is kinder than that at sea, I recommend 3 to 5 years if the instrument is to be run.

    I totally get the "not worth it to me"; we all make those decisions. My suggestion is to reinstall the balance, wedge/lock it and put it away with a note to not wind it and why. Still can be displayed.
     
  10. MrRoundel

    MrRoundel Registered User
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    Probably a good recommendation, Dewey, thanks. Heck, even letting down the mainspring on the chronometer was nerve-wracking, as I did it with the winding key and padded vise-grips. I'm just not set up for clock-sized timepieces, especially with non-conventional escapements.

    I'm a bit shocked to learn that the lubrication doesn't last longer. Live and learn. I understand that a larger mass running dry would be worse on the wearable parts. She'll go back together and set aside for who knows how long, but be none the worse for additional wear. Cheers.
     
  11. Accutronitis

    Accutronitis Registered User

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    I caution anyone against working around the hair spring in any watch without a lot of prior experience because they are so easily damaged or distorted if mishandled in anyway !
     
  12. MrRoundel

    MrRoundel Registered User
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    #12 MrRoundel, Sep 5, 2017
    Last edited by a moderator: Sep 6, 2017
    OK, so after finally working up the courage to earnestly try to replace the staff on my Hamilton chronometer, I bought a staff from Larry Crutsinger. For hairspring removal, Larry suggested that I might try to lever the collet up while spreading it at the same time. I couldn't figure out a way to get under the collet without having too much of a chance to distort the helical hairspring or scratch the balance arm. Then I re-tried something that might be unorthodox, dangerous, or one of those secrets held by the "chronometer-guild".;)

    I had been supporting the balance wheel on a movement-holder made especially for a Waltham '92 model (Not the side with nubs.). It supported the rim, and 60% of the arm, very well. Still, I could not get the collet to do anything but spin...no lift. I tried many times, with many differently shaped wedge-tools.

    As my next "trick", I decided to try again by letting physics(?) work more in my favor, that I would turn the balance over and push from the bottom rather than attempt to lift from the top. I was able to get a well-formed-for-the-job screwdriver tip into the outside of the collet. It got a good enough bite that I decided to twist it while I had another brass wedge brought in from the other side and twisted it to lift while I pushed a bit with the top screwdriver. Voila, the balance dropped cleanly and everything appears to be quite undamaged.

    I used a wooden 16s movement holder to support the balance during this attempt. It worked fine, but didn't support the arm of the balance, just the rim. Fortunately, it didn't take a lot of downward force to get the collet to finally drop.

    Again, while this may not be the suggested method, and carried its own risks, I wish I would have tried it sooner, as there may be a scratch or two on the collet that will be seen under magnification. Nothing terrible, but slipping out of the slot is a reality, especially if you don't have the right tool with the right angle. And seriously, I doubt many have that tool without making one by finding the right angle by trial and error.

    Your mileage/damage may vary. Cheers.
     
  13. MrRoundel

    MrRoundel Registered User
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    #13 MrRoundel, Sep 15, 2017
    Last edited: Sep 15, 2017
    Well, I found out that I really should be a bit more careful when I'm doing what seems like simple task. I decided to start assembling the new staff on my chronometer. I found a number 43 flat hole punch in my staking set that fit over the staff nicely and "SEEMED" to bottom out against he top of the hub that needed to be pushed down over it's shoulder. It took a bit of smacking with my brass hammer before it finally settled onto the hub-table nicely. I felt satisfaction for a fleeting moment. That's when I discovered that the hole in the #43 punch was just a teeny-tiny bit on the shallow side to accommodate the pivot's entire height. I had to double-check to see if I hadn't somehow switched to the old staff/hub assembly. It looks just like it, broken pivot and all. :mad:

    Had I have taken the time to either measure the depth in the punch, or take a closer sideways look through the loupe, I would have seen the "almost" nature of things, and not broken off the pivot on the new staff. :(

    I did check the fit of the punch over the staff, and it all looked right. I didn't count on the depth of the hole being .002" inches too shallow. It was just so close that it was virtually imperceptible. Unless one thought about it for a few seconds more. But seriously, did it have to be so close as to be unnoticeable?

    Moral of story: Look carefully from all angles, and consider all that could go wrong, as something's got a good chance. And, don't use a #43 punch, or probably any watch punch, for setting the hub onto the staff of a Hamilton Model 21. It will be aggravatingly close, but miles away from working. Rats!!!Nincompoop!

    I looked at it again, and it really wasn't as close as I thought. I should have easily seen the depth wasn't going to be enough. I just had to try it on the old one that had an intact pivot. I feel really dumb. I'll try to remember that one must have their head into such work before they get going with the hands.
     
  14. DeweyC

    DeweyC Registered User

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    Well, that is how I learned too! Have to make a punch; not a big deal if you have a lathe. FWIW, I PRESS everything on any staff. You can convert a solid newer crystal press or buy a reloading press and drill a hole for various anvils from your staking set.

    I have at least 5 presses ranging from the Horia to a 1 Ton rack and pinion press. I pick the one that is suitable to the job at hand.

    As for the balance spring, simply make a flat tapered tool from 1/8 inch steel. From the underside of the balance, use the tapered end in the slot to PUSH the balance spring off. Use this same tool to adjust beat.

    If you bang the impulse roller on, there is an excellent chance you will crack it at the impulse jewel slot which then results in that jewel working its way out. Not many rollers left, so be careful. ESPECIALLY on non Hamilton instruments.

    There is a lot of learning from mistakes that goes into the prices by any good watchmaker. Just saying.

    Regards,

    Dewey


     
  15. MrRoundel

    MrRoundel Registered User
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    Thanks, Dewey. Yes, I understand that there is a learning curve, and that along the way mistakes will be made. However, I feel that this one should not have been made. Oh well...

    As I believe I had mentioned before, it's not that I think that professionals are overpaid particularly, it's that I just don't have the cash to put into it to get it done professionally. The shallow punch was a mistake that was quite avoidable, and it cost me more than a few dollars to learn the lesson.

    Funny, I have a buddy who knows a bit about machining and metalwork. He said I might be better off pressing things on and off. But the hilarious thing is that I had an Vigor optician's press around the garage for years. I did a purge a couple of years ago and got rid of it. It probably would have been a good tool for the job. And so it goes. Thanks again. Cheers.

    BTW: Nice write-up on microscopes! I've got the floaters too, and they're in what used to be my good eye. And so that goes...
     
  16. DeweyC

    DeweyC Registered User

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    Just don't beat yourself up. I learned how to make detents because I once broke one. Mistakes are opportunities to learn.

    There is a "Usually works" procedure for floaters. It is literally to drain the eyeball (not a DIY thing). I am giving it a year or so after cataracts to see if my brain filters them out (it is not a particularly smart brain, so...). It gets to be like waiting for "clear seeing" in astronomy. But even my surgeon (Johns Hopkins Dept Chair) would send to me to someone who is bored to tears draining eyeballs. Risks are small and it may not solve the problem, so I am trying to adjust.

    I need to talk to my surgeon, but I swear they are not an issue when wearing polarized sunglasses.

    But the scopes do help with it although there are days when it is still very tedious. Usually I just go work in the forest on those days. Or come up with some topic to write about.
     
  17. MrRoundel

    MrRoundel Registered User
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    Being the hobbyist that I am, I don't think I'll ever get to making detents. I break out in a cold sweat just thinking about it. :eek:

    Good info on the floaters. Thanks. And I think you're right about the polarized lenses. When I first became aware of the floaters, I bought a pair of polarized sunglasses for when I'm windsurfing. They definitely help. I become acutely aware of the floaters when I hang upside down on an inversion table with my eyes closed, and facing the sunlight. It's not to the point where I'd get my eyeball drained, but it could get there. Thanks again. Cheers.
     
  18. DeweyC

    DeweyC Registered User

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    Just an observation and not a personal criticism, but too many people do not take the time to make the tools/jigs required to do a job properly. For example, the roller removal is accomplished with a split state and press. I also have made a number of movement holders, particularly for deck watches and aircraft clocks. Holding things "in the air" and such not only result in unneeded handling which contaminates the plates, the instability makes it more difficult to assemble and adjust.

    See Notes to Young Watchmakers and scroll about half way down to see some examples of things that cannot be purchased.
     

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