After a 15-year break, I'm now accepting repair work again!
I do everything from routine cleaning and oiling (full disassembly and inspection, multi-stage ultrasonic cleaning, reassembly and correct oiling using appropriate modern synthetic oils, timing and adjustment as necessary) of automatic and manual-wind wrist and pocket watches to manufacture of unavailable parts for chronographs or repeaters.
I specialize in Accutron tuning fork watches and I have a large stock of parts and many years of experience working on them.
Please contact me and tell me how I can help you. If you are a collector I've previously worked for, I'd especially like to hear from you.
|Second rewound coil, better result||14 February 2018, 0:09 UTC|
This second try has 2000 and 4900 turns, and it gives a reasonable 4.5uA unloaded. I'm going to try 2000/6000, hoping for a higher resistance than normal on the drive coil, in turn hoping that causes lower amplitude and lower current draw.
If so, that will work better with modern silver oxide cells, which have a higher voltage than the mercury cells these watches were designed for, 1.55 vs 1.35 volts. This isn't usually a problem but does plague some particular 214s.
It would be nice if I could fix that too, while I'm at it!
|Accutron 214 running with my rewound coil||9 February 2018, 22:59 UTC|
A 214 movement running with my cell-side coil (the one on the right). On the first try I didn't get either resistance very close to what I wanted (I got 1.91k, 7.40k with 1850 and 5500 turns respectively, and wanted 2.2k, 6.0k) and the current consumption is a little on the high side. I will experiment with the number of turns. I should probably use the unspooler to measure the wire length, instead of the coil itself, because the diameter on the spool of wire changes very little, but the diameter of the Accutron coil changes a lot as winding progresses. (Click for more pixels)
This 0.015mm wire is about 1 ohm/cm!
|Rewound Accutron 214 coil, completed||9 February 2018, 22:34 UTC|
The completed coil. It works!
|Rewinding an Accutron 214 coil||8 February 2018, 23:22 UTC|
The Accutron 214's cell-side coil is notorious for developing an open circuit, and good coils are hard to find. I'm starting to have success rewinding these in my home shop, and expect to have completed coils in the coming weeks. This is my first successful feedback coil, wound and soldered and measuring a correct resistance. See the video at youtube!
|Vibrating an Elinvar hairspring||29 January 2018, 15:08 UTC|
Hairspring vibrating tools are very cool looking, and useful, and I don't have one. But I improvised with a sliding clamp (a piece of wire) around tweezers and a bench block. Comparing the motion of the balance to the tick of my trusty Elgin made quick work of finding the right length of this NOS Elinvar (Hamilton 992) hairspring.
For the pinning at the center (I made the new collet too) I used the modern scheme of just straightening the inner coil and gluing it into a slot in the collet. Although I think most manufacturers use an epoxy for this application, Elgin recommended shellac if anyone ever needed to repin a hairspring on a Durabalance. It seems to hold fine and I recommend it.
(Click for a bigger image)
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