ESA 9150 Electronic Stop-Lever Spring?

[MrRoundel]

Greetings friends. I have an issue with an ESA9150 electronic movement from the seventies. It was fine when I put it away last year, but is acting up now. When I stashed it, I pulled the crown out in an attempt to save battery life like you can in modern quartz watches. But the problem I'm having seems connected to the balance stop-lever and how it contacts the spring at the top, the one with the ruby contact. When I put the watch in the setting position, it stops as it should, however, it won't start back up with decent motion unless I fiddle with that spring contact.

My thinking is that perhaps this movement isn't really made to tolerate keeping it in setting position, where the spring stays compressed for months or years. Maybe it fatigues the spring a bit, thereby causing my running problem.

All I have now is a video that I made back when I got it running. The spring is just above the plastic block that the stem passes through at 9:00 in the video. It fits into a slot in a little peg and presses against that balance stop arm (looks like a leg, with the foot on the balance).

Does anybody have any experience with these, and perhaps the problem I described? I'm considering putting a bit more bend back in that spring. Any help is appreciated. Thanks. Cheers.

[rogart63]

Have you checked it on the timegrapher? Sounds if it could be out of beat. Yes you can timegraph it. Or maybe it need a service as the oils have harden during the storage. 

[MrRoundel]

Thanks for your input, rogart63. The puzzling thing is that I don't have to twist the movement to start it running. Instead, it merely takes a "flick" or two of the spring at the top of the balance-stop lever to get it running. Would that be the case if it was out of beat?

It runs fine once I start it up, providing I don't have to set the hands. It kept great time overnight.

The only timegrapher I have is the app. that goes with my Ipad. I'll take a look to see what shows up there, providing I can remember how to work it. Thanks again. Cheers.

 

[rogart63]

found an old thread. Hope it can help.

 

[MrRoundel]

Thanks, rogart63. I'll try that balance-swing test next time I pull the crystal. I ended up punting by setting date and time to the present before quickly casing and replacing crystal. Since it's my own watch, I can get away with such badness. :-)

After all, I shouldn't have to mess with the date until...oh crap...the end of this month when I have to deal with the short month we're in. Doh! If I was smart AND lazy, I would have set the date to compensate for that change, if possible. Oh well, I'll pop the crystal again in a couple of weeks and check it out further. I'll also brush up on using the timegrapher.

In the meantime, I have another Wittnauer electronic I bought a while back to clean. It has the later ESA9154 model in it. Thanks again.

 

[MrRoundel]

BTW, I made a rather nifty little tool to position the tension springs that lie beneath the train bridge like an ugly troll. I filed, pounded, and squeezed in smooth-jaw pliers, a brass tapered-pin, until it was thin enough to pass between the plastic tension wheel and the bottom of the bridge. It made quick work of it. On a microscopic level the spring may find the brass sort of "sticky", so it is easy to move the springs over to their plastic wheels.

This time I'm going to save the tool, and mark its container, so I don't have to reinvent the wheel next time. I forgot what I used to handle this last time, on the 9150. Cheers.