Repair + Service: Ultra Precision Digital Automatic Jump Hour watch – Förster 221

This beauty is off eBay – I paid a bit less than a tenner for it, and I hope I can restore it to its former glory. It’s not working at all …

I’m not surprised that jump hour watches didn’t conquer the market, as they aren’t very easy to read. I find it takes me a lot longer to figure out what time it is on one of these than on a normal display with hands.

The crystal is pretty scratched, and the dial has some damage, but, overall, it’s looking good.

Inside lurks a pleasant surprise – a clean Förster 221 automatic movement with 25 jewels, and the hairspring looks good. I might have a chance here! These movements were made in Pforzheim in Germany.

The three rings that indicate the time. The hour ring is a “jump hour” ring, so every full hour, it will take only a couple of minutes to jump from one hour to the next. The minutes and seconds don’t jump, e.g. they continually turn to show the time.

This is a very nicely constructed mechanical movement with auto-winder.

Now it’s time to remove the dials. The second dial just lifts off, and so does the minute and hour dial. That takes me a good half hour to figure out, as I don’t want to break anything …

The jump hour mechanism – the pawl is already removed.

A pretty complex movement.

I start off with a new mainspring.

The gear train in place.

With the mainspring barely wound, this is looking very good.

Time for the three time wheels. Two rivets have come loose, and I have to re-rivet them.

With the staking set, I tighten the rivets.

The two rivets back in place – one keeps the hour wheel pawl in place, and the other provides a sliding surface for the hour wheel.

Wheels and dial back in place.

Now the auto-winder assembly goes back in.

I’ve polished the crystal, and the watch looks pretty good again! I know that the marker inside the crystal should go over the left, but the crystal only fits properly this way. Better not to have it obstruct the dials, anyway.

This one will stay in my collection.

And, of course, you need a really fat leather strap to go with it!

 

14 thoughts on “Repair + Service: Ultra Precision Digital Automatic Jump Hour watch – Förster 221

  1. Hi, i have a lucerne jump hour that was my grandfathers the sticks at the hour turn between 55 & 05 i would love to get it workig again, any advice

  2. Hi Christian
    Messaging you on the off chance that you or one of you followers might have a spare cannon pinion for this movement (FB Forster 221). I would be very grateful for a lead (-:
    Cheers Daniel

  3. Hi Christian,
    I have bought a vintage DAMAS jump hour watch with AS2066 mechanism. It has 3 paralel discs for hours/minutes/seconds pretty much similar with your watch (3rd picture). Due to many times of service of just openings, the second disc is no more paralel with the minutes disc and sometimes the watch stops complely because of too much friction between the minutes and seconds discs. I tried to corect the inclination of the whole and of the disc but i did not succeed. Even worse the whole of the disc became loose and it is falling at any stronger wrist movement. My question is if you have a spare seconds disc (10-11mm) black with white numbers (like in your picture). If you don’t have can you advice me where can i look for it? Or just an advice how can i narrow the whole inside the disc….?Thank you in advance.
    Regards,
    Angelo

  4. Hi, nice watch, i have one with a 225 inside.
    How did you synchronized the hour jumping?
    Mine jumps hour at 55 minutes.
    Thanks

  5. I have a watch that is very similar to this, with the same movement, but branded as a Meister-Anker. Mine unfortunately has a small crack in the acrylic crystal. Do you know if it is possible to find a crystal for these watches or if I can repair it? Nice work on this one — a jump watch with a nice automatic movement is a pretty cool thing! So do you wear it often?

    • Hi Peter,

      My guess is that hell will freeze over before you will find a crystal for this watch 😉

      I’ve worn mine for a couple of days, but couldn’t really get used to taking 20 seconds to tell the time 😉

      • Check the Sternkreuz catalog at Cousins. I replaced one on an old “wacky” looking 1970¨s Alpina President. Found a crystal that was fitting 100%! Could not believe my luck!

  6. I’ve been eying these jump hour watches for some time, but the usually cheap movements have held me back so far. I’m too much of a rookie when it comes to watches, so it will probably take a very very long time to come across one with a good movement, that’s not too expensive, and that did not just get snatched away by someone more knowledgeable 😉
    Nice one Christian!

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