Omega 565 connundrum

[Delroyb]

Evening all,

I have an issue with an Omega 565 auto which is vexing me. Movement has been stripped, cleaned and reassembled. When back together, keeping nice time, good beat error etc. As soon as I place on the auto-wind bridge, instantly gains super fast. It is interfering with the hair spring, but, as far as I can tell, not touching it. Could it be that one of the screws in close proximity to the spring has become magnetised, thus repelling the spring?

I am a bit stuck on this one at the moment! Will try and get sme pictures up tomorrow.

[anilv]

While the magnetised screw can be the cause, two other things come to mind.

1. the seconds pinion sping may be misaligned, causing drag. This is a common problem with indirect seconds movement. On these movement the automatic module restricts the downward movement of the seconds pinion to some extent but if its misaligned or bent it could cause running problems.

2. The autowind has screws on the bottom. Are they in the correct position/correct screws? If the head is too tall it may interfere with the balance.

To eliminate the magnetised screw being the cause (if you don't have a de-magnetiser that is), remove all the autowind gears, screws etc and install the bare auto bridge. If it runs fine then you need to demagnetise the screws or double check the screws are correct. Its quite easy to identify magnetised screws as they tend to stick to your screwdriver.

HTH

Anil

 

[oldhippy]

As you can see from this picture the auto is well away from the balance and hairspring. I would follow what anilv has said, that little spring over the seconds pinion can be a little sod, make sure it is in dead center and a tiny drop of oil has been applied to the spring so the friction is nice and smooth. Here is a picture so others can see the distance between the auto and balance. 

[Geo]

I havn't worked on a 565, but I have worked on a 561 and that is pretty much the same.  I really don't think the problem lies with the centre second damping spring.

If it is distorted causing increased drag it will slow the watch and if it distorted causing too little drag it will cause the second hand to stutter, not increase speed dramatically.  The effect of too little drag is clearly indicated if the watch is held vertical.  As the the second hand climbs against gravity, it will appear OK, but when dropping with gravity it will be very unstable.

I think there is a possibility that the small steel plate underneath the auto bridge may be magnetised.  Compared with screws, it is a fairly large chunk of metal and if magnetised will definately stand a chance of influencing the swing of the balance.

Here are a couple of pictures from a 561 that I worked on showing the steel plate.

I suggest that you demagnetise the complete watch when assembled and see how things go.

[swordfish]

I too suspect magnetism as the culprit.  It's fairly easy to be sure of the diagnosis. Place a compass next to or on the watch. If the magnetic needle of the compass sways rhythmically when the compass is near the watch, but stops swaying when it is removed, the diagnosis of a magnetized watch is established.

--Eric

[Delroyb]

Thanks for the responses. The prize goes to geo. I removed the weight pivot plate and refitted the bridge. Problem gone. Demagnetised it and voila. Thanks all!

[oldhippy]

I have said many times on here you should always demagnetize the watch before you do anything regarding the work to be carried out. Try and remember that and it will save you a lot of trouble and time. Well done Geo.

[rogart63]

It could be something with the ratchet wheel or reverser wheel ? Putting more pressure on the train wheels. And making everything go faster?

Have a look at this. 

http://goldsmithwatchworks.com/our-pdf/563-OMEGA.pdf

[Geo]

Hi Roger, thanks for posting the Omega information.

Here's my take on it.

The ratchet wheel and reverser mechanism apply force to the barrel arbour and spring. If the internal barrel is not lubricated then the spring may not slip as required, this would not be a good situation and could lead to damage of the auto mechanism.

The fact that placing the bridge onto the movement without operating the auto wind still suggests a magnetic problem to me.