A little embarrassing, but after having one too many drinks on Saturday night, my f300 collided with my friend's Rolex Explorer. Initially I thought nothing was wrong, but I noticed in the morning that the watch was not running. I opened the caseback and saw there was a small piece of metal on the tuning fork (See photo). As soon as I removed the piece with tweezers, the watch started running again and has been running without any gain or loss of time.

Does anyone know where this piece may have come from?

 

That's the casing clamp looks to be from next to your battery clamp, should be a screw to go with it.

 

That is a case clamp. It is one of three case clamps (IIRC) that fit on the outer edge of the movement, to hold the movement tight in the case. These clamps are each held in place with a screw. Chances are the retainer screw may have fallen out when you opened the case or otherwise, it is now sequestered deep in the bowels of the movement.

 

Thank you both! I see exactly where it should go now.

 

Those are very good movements. Yours looks like it could use a bit a of a spa; when was it last serviced?

Here's my f300 in the process of service. After a bit of tweaking of the timing it is keeping a constant rate of about 0.5 s/day (or 90 seconds in 6 months).

Michel

 

I am actually not sure when it was serviced, but I definitely agree that it could use one. Do you know of any watchmakers in the USA that service electronic movements?

 

You need somebody that does Accutron movements as a specialty because they are very different than conventional movements. That said, I had mine done by a gentleman based in Thailand (and I live in Boston!). It went really well and recommend it. Less expensive too. The movement in the Omega F300 is the best of the tuning fork models and the only tuning fork model that could be chronometer certified.