Service Elco Automatic/Helvetia calibre 341.


This is truly a rare find as most no-brand gold watches were melted down a long time ago and even more rare it is to find Helvetia calibre 341. It’s getting more and more unusual that I service something that is completely different from anything else I have ever worked on. And WOW was I in for a surprise! The watch has lost it’s crown, but besides that does not look too bad.


Movement looks to be in decent condition, but is not ticking.


I start by removing the oscillating weight and some of the autowinder mechanism.


The dial side is swimming with thin oil.


Wow that is a complicated date change mechanism!


The movement is built up in several layers.


Removing the barrel bridge and you can see more parts.


The autowinder intermediate wheel also makes up the barrel core and has a very nice ratchet construction.


Train bridge removed and I’m finally getting down to the base movement.


Here you can see the train layout.


Here you can see the barrel arbor is hollow where the intermediate autowinder wheel goes through.


Movement cleaned and ready to be put back together.


Mainspring in the barrel.


I see the balance moves freely after fitting the cap jewels.


I start by fitting the centre wheel under the centre wheel cock, placing the barrel in position and putting the centre second pinion in place.


Gear train back in place together with the crown wheel and intermediate wheel.


Now the autowinder wheels start coming back in place;)


Nice how the escape wheel is capped both upper and lower.


Finally the movement is back together and ticking.


This watch preforms very well.


The complicated date mechanism is super snappy and to be honest very impressive.


Movement back in the case.


The pinion in the autowinder had come loose, but was easy to press back in place.


Movement back together and I must say it was much nicer than expected. The autowinder is very smooth and all the pivot holes are jewelled in the right places.It’s got a super snappy date change and good timekeeping. The downfall of this movement is the complexity, it must have cost a fortune to produce. But hey, that’s whats fun to collect today!


I replaced the luminous compound on the hands and dial. It does not matter what people think of the brand because I know what movement is under the dial;)


Very nice!

3 Responses to Service Elco Automatic/Helvetia calibre 341.

  1. Gary says:

    Very nice!,

  2. Michael Pilkington says:

    Hi Mitka,
    Lovely watch. What is your procedure for removing the luminous compound (i.e. radium) from the dial and hands (I can see it flaking on the hour hand). I’ve just bought a Helvetia Cal 831 with similar hands and it’s registering on the Geiger counter. I believe the compound dissolves in water, so I was considering putting the hands in a small disposable container in the ultrasonic. Using face mask, latex gloves etc. I’m not sure about the dots on the dial – wet cotton buds?
    Just how careful do I need to be ?

    • mitka88 says:

      Hi Michael,

      I use peg-wood to remove the compound from the dial and the back of the hands. I do this under the microscope, so that I’m away from the compound dust. I do the work on watch paper that I fold together and throw away when finished. I’m not over concerned about the radiation as long as I do not ingest the stuff. The girls who got sick and died from the radiation poisoning worked with this every day and would lick the brush in their mouth so to give them a fine point.

      I suggest you do it the way you feel the most comfortable:) Trial and error…

      Best regards,


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