Seiko 66B with strange TG trace

[HectorLooi]

I got this watch free with another Seiko automatic that I bought from a local seller last year. I suspect both of are "Mumbai specials" and totally not worth the price I paid.

The insides of this watch were so dirty and greasy that it looked like it was lubricated with used motor oil. The hairspring was a little mangled. But incredibly, the watch was running.

I cleaned the parts at least 6 times. The hairspring was so sticky that I had to use a water based cleaner in an ultrasound and a final rinse in alcohol to stop it from bunching up. It wasn't magnetize because I demagnetized it countless times.

Now that the hairspring was clean, I could see that only the endcurve needed work. I managed to get it pretty nice.

But when I put the movement on the timegrapher, I get a very strange trace. I can't tell if it is the pallet fork or escapement wheel that is the problem. Maybe both!

What do you guys think? 

TIA

[rodabod]

My first guess would be the escape wheel - the repetition makes me think it's less likely to be the pallet itself. Inspection under high magnification the teeth and pivots.

[HectorLooi]

My guess would be the escape wheel too. But I wasn't sure as it affects only the upper trace.

Under 22.5X magnification, the teeth of the escape wheel look like they have been filed. The pallet looks ok, except that there is very little shellac holding the jewels.

[rodabod]

You can remove the balance and advance the escape wheel one tooth at a time to see if you notice anything inconsistent on any of the teeth in terms of how it interacts with the lever too.

The upper/lower traces can be either the entry or exit pallet stones, so hard to tell from that where to look. And it could also be an issue with locking or dropping for example, so it does help to examine the "action".

An easy alternative would be to substitute the part to see the effects of course.

[HectorLooi]

Hmmm.... replacing the pallet and escape wheel will cost me about £15. That's about what I paid for the watch. I will have to think this one out.

[rodabod]

The other consideration is...... does it keep good time? It looks like it may do, and you are achieving excellent amplitude.

[HectorLooi]

1 hour ago, rodabod said:

The other consideration is...... does it keep good time? It looks like it may do, and you are achieving excellent amplitude.

It actually does.

[anilv]

My thoughts are its related to the escape wheel, probably a bent pivot (most likely) or maybe the wheel is out of flat (ie tilted).

A bent pivot pretty much means a new part as its practically impossible to straighten without it breaking.

As for the wheel being out of flat.. it happens but not too common. I would install it in the movement without other parts and see how it spins .. Sometimes you can fix out of flat by holding the shaft (not pivot) and applying pressure to correct.

Good luck.

Anilv