What's the point of the numerous Unitas/ETA 6497/6498 variations?

Thread: What's the point of the numerous Unitas/ETA 6497/6498 variations?

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  1. #1
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    What's the point of the numerous Unitas/ETA 6497/6498 variations?

    Here's what I know (or think I know):


    • Unitas vs. ETA: no technical difference, Unitas came first, got bought by ETA, ETA continued to label movements with Unitas for a while, then eventually started labeling with ETA.
    • Ends in 7: 4th wheel (optional seconds hand) directly across movement from crown ("intended" for crown-at-twelve pendant watches, with the seconds hand at six).
    • Ends in 8: 4th wheel (optional seconds hand) ninety degrees clockwise from crown ("intended" for crown-at-three pocket or wrist watches, with the seconds hand at six).
    • (Admittedly, the 7 vs 8 distinction is often ignored w.r.t. pendant/pocket/wrist so as to intentionally place the seconds hand at three, six, or nine).
    • Lack of -1 or -2: smaller palette bridge with single screw.
    • -1: larger palette bridge with two screws.
    • -2: like -1 but beats faster.


    Here's what I'm not sure about and would love some help with:


    • Is it true that all base models (no -1 or -2) are "old" in some sense, namely that they aren't made anymore?
    • Followup: If all base models are "old" (I think this only implies a few decades) do they predate cheap Chinese replicas? Are they always necessarily Swiss?
    • What is the purpose of the base vs. -1 distinction? In other words, what purpose does a larger palette bridge serve? Why develop the -1 variation at all?
    • What is the purpose of the -1 vs. -2 distinction? I believe the -2s are more expensive. Does a higher beat-rate offer higher accuracy, longer life-per-wind, simply a smoother "buzz", or some other primary benefit? As above, why were they developed at all?


    I ask because I just bought a rather unique partially skeletonized Arnex watch (I presume it's truly Arnex) with a 6497 (smaller bridge, single screw) and I'm curious what its characteristics are relative to the -1 and the -2? The movement itself is virtually unlabeled (it has "unadjusted" written on it, nothing else), although it has been partially skeletonized with a router so perhaps previous labeling was simply removed (although I don't think so since the place where labeling would occur is still blank). The two larger gears are stamped "17 jewels Arnex unadjusted swiss made" with a very distinct picture of five stars (really, it's quite odd, I haven't seen other Arnex watches with these "stars"). I've only seen watches configured this way three other times: two ebay auctions that both ended in October, and a third auction on some other auction website back in 2004 (and the third is only a partial confirmation in that it didn't show the back of the movement so I'm not sure it had those weird "stars" on the gears).

    The weirdest thing is that I wouldn't expect Arnex to use a totally unlabeled completely generic looking movement, yet the movement contains practically no writing. Likewise, I think the 6497 is older than the -1 variant and I'm not sure it was ever generically and cheaply replicated. I was wondering if it predates the era of cheap mass-produced Unitas/ETA replicas. What are the implications of an Arnex-labeled watch with a completely unlabeled movement?

    Here's the complete ebay auction with the seller's photos if you'd like to see what I'm talking about (if you think I massively overpaid, it doesn't really matter now, although in my defense the two similar auctions from October had relatively similar ending prices if you account for various details I won't go into here):
    Vintage Arnex Skeleton Hunters Case 17 Jewel Pocket Watch 14S Free Shipping | eBay

    Does anyone have any thoughts on this?

    Thanks.
    Last edited by Keith W; January 5th, 2013 at 01:43.

  2. #2
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    Re: What's the point of the numerous Unitas/ETA 6497/6498 variations?

    As a followup, I intend to immediately add a seconds hand to this watch. This one is in the no-seconds-hand configuration, which I simply won't stand for. :-D

    I would love any advice on this process. I know I need to buy a replacement fourth wheel with a longer stem, but I have no idea how to open the watch or otherwise disassemble it, although there are some nice walk-throughs and videos online that I think might get me started.

    Cheers!

  3. #3
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    Re: What's the point of the numerous Unitas/ETA 6497/6498 variations?

    Hi Keith,

    I guess you mentioned already the main differences, and they are recorded here:
    bidfun-db Archive: Watch Movements: Unitas 6497
    Another visible difference is the Etachron regulator, introduced in the -1 generation. The reason ist simple: It is the standard device for ETA movements.

    No idea, why the old pallet lever cock was replaced by a bridge. Of course, a bridge asks for less accuracy for positioning the bearing, but this is hard to believe as reason, since manufacturing precision was remarkably enhanced since the 50s, and two screws are more expensive than one.

    The change from the first versions (redesign of the stone-age Units 285) to the -1 redesign is not precise, but it was already in the 80s, and therefore China copies from this calibre likely don't exist.

    Regards, Roland Ranfft

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  5. #4
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    Re: What's the point of the numerous Unitas/ETA 6497/6498 variations?

    Here's the point:

    There is an unmistakeable chain of watch DNA between UT calibers 85 & 86, 285 & 286, 497 & 498, 6500 & 6503, 6497 & 6498, 6497-1 & 6498-1 and 6497-2 & 6498-2. The evolvement of the 16.5''' August Reymond/Arsa/Unitas/ETA movements isn't totally linear. I have examples of main plates stamped 285/497. There are changes between each sub species - some significant, some more subtle. There is limited inter-generational parts interchangeability between single steps. I doubt much of the 85 will work in the 6497-2 but the elimination of each step in between increases the likelihood. When the 85 was designed antishock jewels were the exception for small pocket watches, now they are standard. Many of the changes (and they are to numerous too discuss here) were implementation of technology advancements, some were designed to ease manufacturing. Obviously a new 1940 Ford V-8 coupe would provide vehicular transport - some however prefer a recent vehicle of more refinement.

    p
    Courtesy of ULF.

  6. #5
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    Re: What's the point of the numerous Unitas/ETA 6497/6498 variations?

    Quote Originally Posted by Roland Ranfft View Post
    . . . . No idea, why the old pallet lever cock was replaced by a bridge. Of course, a bridge asks for less accuracy for positioning the bearing, but this is hard to believe as reason, since manufacturing precision was remarkably enhanced since the 50s, and two screws are more expensive than one. . . . .
    Uh Doc, you don't think that it might have a little something to do with the removal of the banking pins from the main plate do you?

    p
    Courtesy of ULF.

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    Re: What's the point of the numerous Unitas/ETA 6497/6498 variations?

    Quote Originally Posted by pithy View Post
    Uh Doc, you don't think that it might have a little something to do with the removal of the banking pins from the main plate do you?

    p
    Would you mind explaining that for me, since I'm really new at this?

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    Re: What's the point of the numerous Unitas/ETA 6497/6498 variations?

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    So, like I said, I want to add a seconds hand. I took a close-up photo of the fourth wheel and if I'm interpreting what I'm seeing correctly, I do not need to replace it with a long stem wheel -- it is already a long stem wheel despite the lack of a seconds hand. Right? Isn't that what this little pin is sticking up out of the axle? So, all I need is a seconds hand, right?

    Just clarifying, since I'm such a newbie.

    Thanks!

  9. #8
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    Re: What's the point of the numerous Unitas/ETA 6497/6498 variations?

    Hi there,

    Quote Originally Posted by pithy View Post
    Uh Doc, you don't think that it might have a little something to do with the removal of the banking pins from the main plate do you?p
    Oops, you're right. It was also my first thought, because present production precision makes adjustable banking pins dispensable. But as I could not make out banking by the bridge even in my high resolution pics, I suspected any other reason for the redesign (e.g. same bridge in any other calibre). But now I took a sample from my stock, and saw that the bridge actually limits the lever motion. But as the "ears" to provide it are hidden by the balance cock I couldn't see it in the pics.

    Regards, Roland Ranfft

  10. #9
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    Re: What's the point of the numerous Unitas/ETA 6497/6498 variations?

    Hi Keith,
    Quote Originally Posted by Keith W View Post
    Would you mind explaining that for me, since I'm really new at this?
    Sometimes Google helps not to invent the wheel twice. With "watch banking pins" the second entry covers both, adjustable banking pins and solid banking be the bridge:
    Watch Glossary - Escapement - Banking Pins

    Regards, Roland Ranfft

  11. #10
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    Re: What's the point of the numerous Unitas/ETA 6497/6498 variations?

    Looks like it. As long as it is long enough to fit the seconds hand tightly and still prevent it from touching either jewel or bridge. Try it and see.

    Hartmut Richter

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