Not only Bulova built tuning fork watches. The Swiss movement manufacturer ESA also made a tuning fork movement under licence from Bulova. Amongst others, Omega used this movement in their Omega Electronic Geneve Chronometers.
Kim sent this one over for a service, so let’s see what lurks inside…
A first look clearly shows the two coils that keep the tuning fork humming.
The bottom plate is fairly standard.
The bridge has the tuning fork attached to it, and the index and pawl fingers, and of course the index wheel that is driven by the index finger. Overall, I prefer the ESA construction over the Bulova one, as it’s easier to work on, and the pawl finger position is easier to adjust.
With the little bridge removed, you can now clearly see the index wheel (the smaller of the two wheels in the centre).
The top plate is an easy enough construction, with the second hand arbor having a spring pressing against a plastic ring to make the movement of the hand smoother and to prevent vibration.
With the little bridge removed, you can see the plastic ring, and the wheel above that contains the clutch so that you can set the time without turning the index wheel.
Now it’s time for the bottom plate.
The electronics are kept away from the cleaning machine.
Reassembly starts with the top plate.
Now the index wheel and bridge are mounted.
Then the coils and circuit go in.
Now the tuning fork bridge is mounted on the top plate, and, after putting the battery in, I can adjust the index and pawl finger position.
Finally, I put the bottom plate back together.
With the dial and hands back on, I case the movement, and the watch is humming happily again.
Hello. I have a non working zenith xl tronic quartz (esa 9162 movement). Many of technicians in Greece where I live told me maybe a coil of the movement is the problem and have no parts to repair it.
Are you servicing this kind of movements? And if yes how much will be the cost of repairing this kind of watch.
Thank you for your time,
Michael
Sorry, but we only work on mechanical watches.
I sent my ‘D’ shape constellation to Fix My Watch in Leigh for a service. Since receiving the watch back I have had problems with the date change-over. It works properly for days then the date does not change – it has to be done by turning the winder. The terms of Fix my Watch are written so that it is costly to return and they charge for ALL postage. They also put the price up from £150.00 for a quartz to £250.00 the price they charge for a mechanical service. They state that an electronic movement is more work intensive. They upped the price fro £150.00 as they originally quoted to £250.00 when they received the watch in their hands. (A Fait Accompli !!!) As they can charge again for postage etc. I shall not return the watch to them I advise any prospective customer to be careful when dealing with this Company.
I bought my constellation new in 1972. I had it serviced as it ceased function and it was successfully repaired. About five years ago the hands stopped although the humming continued. I assumed it needed a battery replacement but when a new one was installed the battery drained so I had the battery removed . Since then, it has been in my watch collection but I was hoping that it could be repaired as it has a lot of memories for me. Can you recommend a repairer in the uk who could assist please?
Try Paul Wirdnam.
I can sort it–I specialise in Tuning Fork types, all makes.
Guess Cristian wont mind me giving my address as he’s not doing these himself….
vegoildiesel@yahoo.com
where in uk can i get omega f 300 hz ( tuning fork mechanism ) fixed?
Try Paul Wirdnam.
hi frends please help for adjast speed this cal omega watch thank you
There are adjustment screws for the effective length of the tuning fork
Oi . Vejo que este Omega esta com uma Bateria Renata 390 ? O original seria 343 com mercúrio que não se fabrica mais , o substituto seria Renata 344 de óxido de prata . Então a 390 também seria um substituto aceito ?
Qual e o intervalo de tempo recomendado para revisão para este calibre ? Obrigado
Ricardo
Do you happen to remember the sizes for the hands? I’m looking for replacement hands
Isiah
I am afraid I don’t.
Std ETA size hands will fit–ESA became/took over/combined to form ETA. who themselves taken over/owned by Swatch….
Hole Sizes, 1.5 hour, 0.9 minutes, 0.25 seconds.
Hi Looking for a turning fork for my omega for repair, where can i buy one ?
Hmm, an odd part to break… you probably need the index fingers, and you are better off letting somebody else do that work…
eBay is a good source of parts, or complete donor movements.
As pointed out by Christian these are better left to a competent watchmaker who has experience and knowledge into these little marvels! Way too many have been damaged by incompetence!
Do you know of a source for replacement coils?
I’m afraid not.
Donor movements!
More or less any MOSABA movement will do.
Titus tuning fork watches are good as part donors since the lack of brand name does lift the prices.
You can also use Certina, Eterna, Iwc or Longines, to name a few others.
Brilliant post
Brilliant post, do you know where I can get a index wheel for my 9164 movement
Christian,
Great post and very informative, I didn’t know you could handle these ESa movements! I have an Omega F300 Seamaster in a ‘cone’ case which has been recently serviced in the UK. However, it has gained time on two separate occssions, once just before it was serviced and the last time just after it was posted back to me. Is there a possibility that the index and pawl finger position is either not being not correctly adjusted so that it will be able to withstand the normal knocks and bumps of daily wearing without it gaining bursts or is the issue that the index mechanism is moving or slipping during transit in the post? Is this type of movement more susceptible to knocks in general?
Paul
Paul,
Tuning fork watches are quite sensitive to knocks. If I cut the hedge wearing my Accutron, it will gain 10 seconds or so during the process.
I luv everything about the watch apart from the battery!!
Maybe they could make a little wind-up version 😉
cool!! 🙂
I have a lot of love for tuning fork movements… precision with the soul of a mechanical – also, they sound great 😉
Excellent!