Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles

The Eterna Caliber 39 is one of the most interesting developments to come from the modern Swiss watch industry. Although we covered the news about the Eterna Caliber 39 here some two years ago, we had not heard too much about how much progress Eterna had made with developing the Caliber 39. By early 2015, that has at last changed, and we have seen all major iterations of the Eterna Caliber 39. It is thanks to this spectacular encounter that coming up now is the third episode in our unique Movement Hands-On Series. Get your popcorn and beverage nearby as we are about to learn a lot about what may very well be the most interesting and viable alternative to the famous array of ETA movements.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles

ETA cutting out the supplies of its semi-assembled movement kits entirely by 2011 and drastically and continuously reducing the amount of complete calibers it sells to third parties – read: non-Swatch Group – customers were some of the defining happenings for the 21st century watch industry. ETA had been the key supplier of movements to an incredibly high percentage of all Swiss watch brands – small or large, fashion or high-end – and with their cutting supplies starting at around 2007 (they intended to begin a couple of years sooner but were met with strong opposition from the Swiss competition agency), stopping movement kits entirely by 2011, and today, selling full movements far below demand, brands are forced to look for other sources for the engines of their watches.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles

The ETA automatic 2824-2 with date, the hand-wound 6497, the automatic chronograph 7750 and 2894-2, as well as their numerous variations are just some from the vast selection of mechanical movements that are still highly preferred by brands to this date. These highly reliable, cheap-to-maintain and relatively easily customizable movements in many ways played a major role in the modern watch industry. Available in three different finishing qualities and even COSC certification, brands could easily find calibers that matched the price segments they were aiming for, while the famous "workhorse" reliability meant that they hardly had to worry about after sales nightmares – at least when it came to the movements, that is.

You can read a lot more about the reasons why and the exact ways how the Swatch Group and ETA have been reducing movement supplies in our unprecedented A Brief History Of ETA: THE Swiss Movement Maker article. In it, we of course also discuss the history of Eterna and ETA – including how the small workshop of Dr. Girard & Schild started out as a movement kit (ébauche) manufacturer in 1856 and was ultimately renamed to Eterna in 1905, and also how ETA, the movement manufacturing branch of Eterna, came to be in 1932.

We are living in very different times, and ETA and Eterna are, in fact, two very different companies today – the former is owned by the Swatch Group while the latter, since mid-2012, belongs to Citychamp Watch & Jewellery Group Limited (formerly known as "China Haidian Holdings Limited"). What Eterna's watch collections have to offer is for another discussion, as we are here to dive deep into the intricacies of some of the most interesting watch movements out there – and so, without further ado, let's look at the Eterna Caliber 39, why it is important, and why it is so technically interesting.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles
The large space in the lower right quarter of the movement accommodates the automatic winding module

As we mentioned above, one of the key advantages of ETA is the remarkable diversity of its movements, which allowed it to supply a large variety of brands – regardless whether they were going for greater affordability or more high-end execution and price-points – with calibers that fitted their requirements, both in terms of functionality and reliability. Eterna had to realize that if they were to offer a viable alternative, they must be able to cater to a similarly large variety of customers – who, in turn, will of course come with different expectations and ideas.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles
The hand-wound, already functional base caliber. Note the large space left out for the automatic winding module

The Eterna Caliber 39 was designed from the ground up to be easy to modify: the base movement that you see above carries all modifications. What you see there is the foundation to all Eterna Caliber 39xx (xx to be replaced with the respective number of the variation). The base movement as seen there functions without anything else being added to it: it will give you the central hours and minutes, seconds on a sub-dial, and feature hacking seconds as it is. The base Eterna Caliber 39 runs at 4 Hertz (28,800 vibrations per hour), is 30 millimeter wide and provides 68 hours or less of power reserve. When I say "68 hours or less," that is because additional complications add drag and take a toll on power.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles

The first interesting bit here is that it will serve like the chassis of a car, to which extra bits and pieces are bolted – in this case, a large variety of complications, but more on those just a bit later. When it comes to many brands who developed their own new (or "new") movements, their decision often times was to create something that was "integrated" – think of the Unico from Hublot or Breitling's chronograph B01 for example – meaning that the base movement and chronograph functions are designed and constructed in a way that key components of each may be located in the other section. That sounds good and may result in a thinner movement, but it also makes it considerably more difficult to modify (and service) the movement, whereas a base movement with a module are easily separable – and hence, serviceable and modifiable.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles
No automatic winding, just a decorated plate to cover the hand-wound movement

As I said, the base Eterna Caliber 39 works as it is, no modifications are needed. Therefore, what you see above is the most basic version of all: the hand-wound iteration, with just a top plate with swirling stripes added for decoration and to cover up the excess space underneath.

An important thing to note is that no matter how the base caliber is modified, the mounting points remain the same, meaning that the brands need not redesign their cases (being designed to be thick enough for the different complications) when fitting a different movement: the hand-wound, the automatic, the chronograph, and all other versions are secured to the case at the same mounting points, which can be a major cost saver, given that a larger quantity of the same case can be manufactured, as opposed to different ones to house the variations of movements.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles
Automatic winding module has been added

The second iteration adds automatic winding to the base, as the self-winding mechanism fits into that larger open space you saw a bit further above, between the crown mechanism (keyless works) and the balance wheel. Given how popular a regular automatic is going to be, it makes sense that this small complication pops into its designated space, making it easy and relatively cheap to install.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles

On the dial side, further complications can be easily mounted onto the base, these – to give a few examples – can be the date displayed on disc, the date displayed by a central hand, second timezone displayed on a sub-dial or by a central hand. All this has already provided us with a large number of options, allowing brands to easily create many models with small variations, meeting a larger variety of customer requirements.

Eterna Caliber 3903A is the basic automatic winding movement (with hours, minutes, seconds and hacking) with date, Eterna Caliber 3914A adds a GMT function to that list, while Eterna Caliber 3945A is the same as 3914A but with central seconds. The movement is 5.6 millimeters thick (5.9 with central seconds), which, considering the 65-hour power reserve, is acceptably thicker than the similar ETA 2824-2 that packs the same functions but is just 4.6 millimeters thick.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles

The fourth major version is the fly-back chronograph which, again, is a module fitted to the back of the base movement. Interestingly, the chronograph module itself costs about 20% more than the price of base movement, rendering the chronograph movement's price over double that of the base. At 30 millimeters wide and 7.9 millimeters thick, the Eterna Caliber 3916A (with time, 12-hour fly-back chronograph, and date) and the Eterna Caliber 3927A (the same as the latter but with added GMT functionality) are both exactly the same size in diameter and thickness as the famed ETA 7750 and all its most important iterations.

It is very fascinating to see how Eterna's engineers managed to create something modular that is to a tenth of a millimeter the exact same size as the 7750. The reason for that is, of course, simple: the Eterna Caliber 39 was purposefully designed to be an alternative to ETA's movements, and the only way to offer an alternative to brands is by allowing them to keep their present case sizes and internal construction, saving them the enormous costs of re-engineering their cases. Despite the similarities, the Eterna Caliber 39 provides 60 hours of power reserve, half a day more than the 48-hour life of the 7750 movement family. That may just be enough if you put the watch down on Friday and only wear it again on Monday morning – a time frame all modern mechanical watches should cover, in my opinion.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles

From a simple hand-wound movement through date and GMT equipped automatics, all the way to the fly-back chronograph, we have looked at what will certainly be some of the most popular variations of the Eterna Caliber 39. We were told that custom decorations will also be made available, including color coated movement components and custom rotors. The point here, really, is to offer a movement (well, with all variations, Eterna says 88 different ones altogether) that will meet the needs of a large range of watch brands.

Technically, the Eterna Caliber 39 is hugely impressive because – as you surely have heard from engineers before – it is incomparably more difficult to make something simple than complicated. The fact that such movement components can be replaced as a whole with such ease is an incredible achievement – something that many brands will surely appreciate.

Movement Hands-On Series Episode 3: The Revolutionary Eterna Caliber 39 Feature Articles

We will have to see how the Eterna Caliber 39 performs in the long run, both in terms of reliability and of course in overall success. Beyond what is expected to be a slight premium over other options (like Sellita movements) a bottleneck may be Eterna's manufacturing capacity, as they started out by producing just 5,000 Eterna Caliber 39 units in 2013, with production being raised to about 20,000 per annum soon. That, of course, is nowhere near ETA figures – but I do hope to see the Eterna Caliber 39 (in one of its 88 variations) in more and more watches in the more affordable price segment.

  • antjay

    Great article , thank you David .
    I am hoping that these movements are widely adopted . Do you know of any makers who have picked them up ?

  • SantiagoT

    This here is one great article David (as usual). Thanks for the effort.

    Let me ask you one thing tho: what about COSC certification? They are going to need that too.

  • WimadS

    Great informative article! Clear, interesting and easy to read writing as always from you David. IMHO certainly the best author on ABTW 😉

  • DG Cayse

    Very nice article Mr. Bredan. Easy to read and understand. Thank you.
    Eterna is jumping in to provide a valuable asset to the horological world.
    As to manufacturing capability, I think the parent company already has this up and running with at least two new facilities.
    Perhaps some short-falls in the beginning; but I look for the longer term to move these into a lot of inventories.
    How about parts availability of caliber items for repair shops? This would be an uncertainty that could be a problem.

  • Thanks for the update David. I remember asking Eterna about availability of the caliber 39 back in 2013 at BaselWorld. At that time they said they only had enough capacity for the needs of Eterna brand watches. So its nice to hear that production has ramped up and hopefully they will have movements available to 3rd parties.

  • iamcalledryan

    Good coverage. I have high hopes for Eterna. There is something fitting about the ETA alternative rising up from the same stock of ETA itself. And I love that they can showcase their movements in the models that they design and manufacture too.

  • WimadS

    iamcalledryan Good observation! I think it could prove quite beneficial to have a single watch brand linked to the movement to showcase it. ETA kind of has the image of a soulless mass production movement. Having one brand associated with the creation of these movements (eterna) kind of gives it an identity which makes it feel like a nicer movement (eventhough it is essentially the same kind of mass produced movement).

  • Despite the question on the reliability of new designs, I’m excited about the new dial and case design possibilities that breaking the mold of ETA will bring about, especially in chronographs.

  • Johnny C

    Great content guys…   Super informative and straightforward.

  • I_G

    First thing to do: swap the Times Roman date disc.

  • DG Cayse

    Just a note:
    The ETERNA website still shows their use of the Selita SW and ETA 2824 in their offered models.
    And, makes no mention of the  Caliber 39 models in their online “catalog” section.
    Perhaps it’s time for an update on their site?

  • DG Cayse

    MarkCarson Good point. Other makers are joining the game,i.e. Miyota, Selita, Soprod, Seagull, to name a few.
    Some will be thinned out and some will prosper. It’s all good for the consumers in the end game.

  • DG Cayse

    Well, since last night, it looks like the  Caliber 39 has been added to their “catalog” section:

    Good for them…and us.

  • WillyChu

    From link in this article:

    “What we must mention though is that ETA calibers come in four different “grades” that correspond to different levels of finish, quality of execution and – unsurprisingly – different prices as well. Standard is the cheap and cheerful solution with an accuracy of +/- 12 seconds per day and 30 seconds maximum positional variation. Elaboré is a step up with a performance of +/- 7 and 20 seconds in those fields. Top Grade has the finest finish and higher quality components overall than the previous two grades with an accuracy of 4 and 10 seconds. Finally, there is the Chronometer grade which is a Top Grade movement with COSC certification.”

    Do these Eterna movements have these different grades of quality?

    Also, commenters here often pooh-pooh ETA movements as inferior, but as you see there are different grades.  Why do manufactures who use better grades of ETA movements not indicate this in their specs?

  • DG Cayse MarkCarson Prices will be higher than the old days (of readily available ETA movements) but at least there will be more choice.

  • WillyChu I switched to using Elabore grade ETA 2824-2 movements over a year ago (and do mention the grade on my website). And yeah – they are even harder to get and cost more. In my experience, even a Standard grade ETA 2824 will perform better than +/- 12 seconds per day and 30 seconds between positions. More like within 0 – 3 seconds in any given position and less than 15 seconds deviation between all positions. Even a Mityoa running at 3 Hz can be very accurate in any given position.

  • Astronuts

    As an owner of mostly divers, my main concerns are with reliability, accuracy, ease of sevice and not decoration.  Of all of my ETA watches (moslty 2824-2’s  and  2836-2’s) I couldn’t tell you thier respective grades.  They have, however, been very robust, and surprisingly accurate.
    If Eterna can boast it’s toughness over say a 10-15 year period, then it may be something for me in the future.  So far my Soprod A10 – Sellita SW200’s and a few Miyota 9015 watches have been good replacement engines…even at a price point/value  ratio comparable to ETA.

    Does anyone know if these are bi-directional winding? How would Eterna compare price-wise to Miyota? I ask this because as an average Joe watch guy, I just bought a beater 316L cased shappire topped 500m diver w/9015…for 200 euro, and I have to say it has been a great watch so far.

  • BAwristwatchfan

    aBlogtoWatch Outstanding, informative & just interesting article! Thanx so much!

  • au bloc

    Maybe with a larger movement the date won’t be located so awkwardly. Recall the ETAs were originally designed for much smaller cases than is common now.

  • egznyc

    Can’t agree more with all the comments about how well written and informative the piece is.  Thanks, David.!  

    The couple of questions that came to my mind were (1) with that space in the lower right quarter of the movement, I wonder if it’s possible for Eterna to create a mini-rotor for automatic winding down the road, which would make for an automatic that was no thicker than the handwound version.; and (2) not specific to Eterna movements, but couldn’t an integrated (non-modular) movement be built that would nonetheless be easily maintained/serviced?  There must be such movements out there, in fact; right?

  • socabaptist

    Great Article, 

    I feel smarter already. This is an interesting development. I love the approach, it would be interesting to see what are the prices points from the low to the high end of this movement. Of course that will come once it is used in the different watch models. This is definitely something to look forward to.

  • David Bredan

    egznyc Thank you for your kind words!
    1) As for the micro-rotor, that is a difficult (and not always extremely reliable) complication, which explains why most of the time it is found in more high-end watches. Also, the space left out is definitely not deep enough to fit a micro-rotor and its wheels in there. Micro-rotor movements just about always have the gear train and other parts laid out in a way so that the full height of the movement is available at the cutout for the micro-rotor. Some pictures of this Roger Dubuis nicely illustrate that movement design: while that’s a good idea, in its present form of the base Cal. 39 I don’t think it’s possible, unfortunately.
    2) Many brands have claimed that their newly designed integrated chronographs are easier to service – and I’m sure that to some extent that is true – when compared to traditional chronograph movements, for example; but hardly in comparison to modular constructions.

  • David Bredan

    Astronuts It is of course much too early to speak about the reliability of the Cal. 39, but I do feel rather confident about the quality of their construction (I am really looking forward to reviewing watches with this new movement to see how they will actually perform). As soon as that happens, we’ll have a post up here and discuss that in detail!
    As far as price points are concerned, I am not aware of the price differences between the different grades (and prices are not public), but I can say that I do not expect to see the Cal. 39 to be an equal replacement to the 9015 or more basic Sellita calibers. I have watches with both of those and they are great workhorse movements, but I do believe that the Cal. 39 will come at a premium when compared to those – for all the reasons mentioned in the article. In short, the Cal. 39 is not an ETA clone but a completely new modular design, hence with better power reserve and more flexibility in functionality. Today, at a time when watches with 7750 movements are often priced at $6-$8,000 or more, I expect the Cal. 39 to be used in watches that have a price tag at least around $2,000 or more (that is nothing more than a guess, we’ll have to see how that turns out over the next few years)

  • David Bredan

    WillyChu Thank you for your comment. I would say that recently there have been considerably less comments against ETA movements and their quality. A few years ago, when the marketing machines were fueling the in-house craze at 110% many were made to believe that ETA movements are inferior. Over time there have been a few newly released in-house movements with quality / construction issues while ETA movements kept on ticking as though nothing happened – so maybe that has also had an effect.
    As for different grades, Eterna will offer different grades and, MarkCarson , COSC certification will also be available.
    I’ll share a little snippet from my conversation with the CEO of Eterna-Movements that I for some reason ultimately did not include in the article: when I asked him about the availability of a COSC certification for the Cal.39 his very confident reply was something like “People don’t want COSC, they want a good movement”. To me that beautifully showed how the emphasis is on creating a great movement family that performs well out of the box, and not on saying “if you want something really good, you have to get COSC”. That was just my understanding, though.

  • David Bredan

    DG Cayse I am really looking forward to finally seeing/reviewing a new Eterna watch with the Cal. 39 inside – preferably the fly-back chrono! 🙂

  • David Bredan

    DG Cayse WimadS SantiagoT antjay Thanks you all so much for the kind words and the great feedback!!
    To answer your questions, we have met with a few brands in BSW who said they were planning with these movements, but nothing for sure just yet.
    There will be COSC certification available, at a premium, of course.
    As far as the availability of replacement parts is concerned, that is indeed a very good question. Given that the Cal.39 was designed to be used by a great variety of brands I don’t think 3rd party repairers will be cut off from the supply of replacement parts – rather, we have been seeing major brands with expensive proprietary movements trying to keep any and all servicing for themselves.

  • egznyc

    David Bredan egznyc David, thanks for your helpful responses.  I really appreciate it.  Sounds like there are pluses and minuses to every decision with regard to movement design.  Not too surprising, I suppose.

    Here’s a different question entirely, perhaps one that has been addressed previously at ABTW:  I’ve read that one cannot overwind an automatic movement, but I’m not sure whether this means just from wearing the watch or having it on a winder, or if one cannot overwind by rotating the crown over and over.  It’s possible, I suppose, that some automatic movements cannot be overwound to the point of breaking either the stem or the mainspring, while other automatics can be damaged in this manner.  I just don’t know much about this but I’m curious if you or anyone could shed some light on this.  Thanks!

  • egznyc

    Minor issue: weirdly enough, the link you provided doesn’t take me to the Roger Dubuis watch you noted, but to an Ikepod.  No worries, though — I understand what you mean.

  • egznyc An automatic uses what amounts to a friction clutch so that after the mainspring is fully wound, additional torque (from the rotor or the winding stem) just causes a slippage and the main spring does not receive any more “winds”. In contrast, there is a fixed mechanical connection in a hand wind watch and over winding causes more torque – as much as you crank into it – to be applied the mainspring.  At some point you will give up as the pressure makes it feel like the winding has stopped. Or if you re Conan the Barbarian and keep twisting, something will break. The winding stem or the mainspring or a gear.

  • TomasinaCovell

    What stem tap sizes are they?

  • Tomasina Covell

    I’m sure they won’t sell me parts.

  • egznyc

    Thanks for the information. Not that I’m about to turn the stems on my automatics forever …. As for my hand wound piece, lucky for me I’m no Conan. Makes me think: Arnold is only including automatics and quartz pieces in his brand. Coincidence? 😉

  • Time2Go

    Another great article David.  This series is excellent!

  • AXL0013

    Regarding the 3914A and 3945A, does the GMT complication function the same way as the ETA 2824-2? I haven’t been able to find a definitive answer even in the previous ABTW articles on the Royal Kontiki. I’m really keeping my fingers crossed for a Rolex-style jumping 12-hour hand.

  • AXL0013 I can’t say what the Eterna movement does.
    However, the ETA GMT movement is the 2893 (not the 2824). The setting of the GMT function on the 2893 via the crown is to turn the crown clockwise in the first pulled out position (date setting happens via counter-clockwise turns). The GMT (24 hours) hand then jumps (forward only) an hour at a time during setting. But it does not jump during time keeping if that was your question regarding the Eterna movement. With the crown fully pulled out (time setting position) on the ETA 2893, the GMT hand moves along with the hours and minutes (backwards or  forwards smoothly).

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  • Francis Jacquerye

    The near identical measurements of the full calibre 39 version with the 7750 suggests that it might be a downstream consequence rather than an upstream decision as Eterna would like us to believe.
    The position of the balance wheel, intermediary wheels and barrel wheel are very similar to the 7750, so I wouldn’t be surprised if it turns out that Eterna started from the 7750’s architecture to create the 39. That wouldn’t take any merit away from their achievement, but history has taught us that there is always more the story than a watch company is willing to share: TAG Heuer 1887, Soprod A10, Bremont BWC/10 anyone?

    • After spending more time studying the specifications of this movement, I now understand that it is genuinely a novel design, that was developed by also taking in consideration the best existing architectures.
      I must diligently eat up my former sceptical comments and tip my hat to Eterna for doing a thorough work on this new line of mechanisms! I look forward to seeing it being used on third party brands.

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  • Boogur T. Wang

    A question about this great ‘new’ motor:
    “Eterna Caliber 3903A is the basic automatic winding movement (with
    hours, minutes, seconds and hacking) with date…”
    Is the 3903A hand-windable in addition to hacking and auto-wind?

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  • 4tens

    Great stuff here!
    Thx David!

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