Service + Repair: Eterna 520H

IMG_2395One of Anders’ watches, and it’s a pretty rare military Eterna watch with the 520H movement.

You can see the luminous compound in the usual “military” style, e.g. generously and not too carefully.IMG_2398
The timegrapher image shows that a service is in order.IMG_2530

The dial is in pretty good condition, taking the age of the watch into consideration.IMG_2531

Look at the gunk next to the barrel arbor on the plate – that doesn’t look promising…IMG_2532

The barrel bridge has a lot of gunk on the barrel arbor, too.923-01

Under the microscope, you can see the damaged plate where the barrel arbor has ground into the plate.923-02-anders

And the same on the barrel bridge.IMG_3536

I order a set of bushes in the right diameter.IMG_3537

To fit the bush, the hole for the barrel arbor in the plate has to be broached. The biggest problem here is to stay centred, as otherwise, the barrel will not sit correctly in the movement, and touch the plate or bridge.IMG_3538

You can see how the broached hole is properly centred in the plate.IMG_3539

Now I can press in the new bush and carefully rivet it into the plate.IMG_3540

The bush is pushed in, but needs to go up a bit further.IMG_3541

Once it’s sitting correctly, I broach the inner diameter for the barrel arbor. Slowly does it.IMG_3542

The barrel arbor fits nicely.IMG_3543

The new bush is thicker than the plate, so I will have to take off some material.IMG_3544

With a milling bit, I take off what’s too much.IMG_3545

In order not to damage the plate, I will leave a tiny bit of the new bush to stand proud of the plate.IMG_3546

Here you can see by how little the new bush protrudes from the plate.IMG_3547

Now the same has to be done to the bridge.IMG_3548

The new bush fitted.IMG_3549

… broached …IMG_3550


… and ready to be put back together.IMG_3292

Now I hand over to Mitka, who is putting the watch back together.IMG_3294

The gear train and barrel are in, and the bridges are on.IMG_3296

The set lever spring was broken, and we find a new one.IMG_3298

That’s looking pretty good already.IMG_3299

The complete movement.IMG_3300

The shock protection has an interesting construction.IMG_3302

Dial and hands are left original.IMG_3334

The crystal is a stepped crystal, that is screwed in with a ring from the back.IMG_3487

The movement is cased.IMG_3489

A nice dust cover for the back.IMG_3492

And the watch is complete again.IMG_3497After a bit of running in, this is as good as it gets. Proof that the barrel arbor is running very smoothly indeed in its new bushes.image1

As requested, a photo of the case back!

27 thoughts on “Service + Repair: Eterna 520H

  1. honestly, in all your repairs, have you seen more consistent timographer results than a freshly serviced eterna? a lot of beautiful flat lines.

  2. A question about broaching out the plate holes. Is there a reason one doesn’t drill them out to slightly under the desired diameter, and then finish with a broach? Would the existing oblong and presumably now off-centre hole throw the drill bit off? Perhaps I’ve just answered my own question.

    • It doesn’t take a long time to broach the hole to the desired diameter, and whilst broaching, you have full control about staying centred. If you take a drill to it, chances are very high that the drill will go off-centre, and then you have ruined the plate. So you did indeed answer your own question 😉

      • If one were looking for a reason to justify the purchase of a lathe faceplate to a significant other, this may be it 🙂

        An impressive result for the timekeeping btw.

  3. Very nice watch, and a awesome work with those bridges! I have a civil version with the same movement, great watches that can be bought for pocket change.

    On the picture with the hands fitted to the dial, is the minutehand fitted wrong or is it supposed to have that much lume?

  4. Great dedication and skill to repair this wonderful old Eterna, congratulations. I must send you my Angelus Datoluxe for service…

  5. Lovely thing. I need to ask: what does Anders do with these watches? Do you have an online store, or are you a collector? If so, you have some really great watches!

  6. Watch arrived and I love the looks and work.
    Another great achievement! A big Thank You to Christian and Mitka for their “never give in” attitude:-)

  7. I love the look of the movement with the curved and beveled edges on the plates. I like manual wind movements more than automatics too. Of course that movement looks a lot better now that the plates have been repaired! Nice work as usual, guys!

  8. Did you fit a new crystal or polish up the existing one? I believe the MOD style stepped crystal are pretty hard to come by these days?

    • This is not a standard watch as such. The ATP watches was for general use. The WWW was ordered with precision adjusted movements matching the chronometer spec. They were intended for special duty.
      These WWW watches was ordered for WW2 service, but mid to late 1945 deliveries meant they were not actually used then. The British military ended up issuing WWW watches in various conflicts up to the Falkland war. Also loads of surplus was sold to the general public.
      Altogether 12 makers ever produced WWW models. All to the same spec These are known by collectors as “The Dirty Dozen “. Loads of info to be found on.the internet

  9. A nice watch – and very nice to have what appears to be an issued one… did it have any MoD type markings on the back?

    Re-bushing looks like one of those things that is simple in concept but difficult in execution. I’ve seen it done in old clocks, but rarely in watch movements.

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