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Omega 613 low amplitude solved. Don't forget to check this jewel is you have low amplitude !


mikepilk

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Not a question, but I thought I'd post this for general info.

I was really struggling to get the amplitude above 190 deg on an Omega cal 613. 

I'd fitted a new mainspring, and all the pivots looked straight and clean.

Gear train running freely, barrel arbor not sticking, no loose jewels, and jewels looked good under the microscope. Hmmm

 I always have a good look at the jewels to make sure they are clean and not broken, but have never bothered checking one area - inside the Incabloc hole jewel.

The cap jewel and top of the hole jewel looked good, but it was only when I looked underneath I found the problem. 

I don't know what the black bits are. They had been cleaned twice in my ultrasonic in lighter fluid, then IPA. Obviously not enough,  not easy to get a brush in there.

I put in new jewels and now have 275-280 deg amplitude :woohoo-jumping-smiley-emoticon:

Another item for the check list !

 

 

 

 

 

 

 

 

WIN_20180916_17_26_20_Pro.jpg

Edited by mikepilk
typo
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I assume that the friction spring sits on top of the sweep second pinion ?

The last one broke, and this one doesn't want to sit on top correctly, it catches the pinions stopping the watch.

I don't want to bend it and break another as they are not cheap.

WIN_20180921_18_26_04_Pro.jpg

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50 minutes ago, rodabod said:

You have no choice but to correct that spring or replace it. The friction needs to be adjusted sometimes anyway. They run dry, FWIW.

Thanks, I did wonder about lubrication. 

Despite their quality, I do seem to spend a lot of time sorting out Omega movements!

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I am not liking the arch in that spring. It seems to me that the double bend at the base near the screw hole is what is supposed to be supplying the tension.If it were my money, I would flatten that spring a bit , making it effectively longer. it would overshoot the cog and not catch.i would do my bending at the base.

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3 hours ago, yankeedog said:

I am not liking the arch in that spring. It seems to me that the double bend at the base near the screw hole is what is supposed to be supplying the tension.If it were my money, I would flatten that spring a bit , making it effectively longer. it would overshoot the cog and not catch.i would do my bending at the base.

I think you are right. I found some pics of other movements and the spring looks straight from the double bend. I think the arched bit is being pushed down by the bridge which is then applying too much pressure. 

It's not great engineering design when the performance of the movement depends on how one small spring is bent, Omega or not !

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20 hours ago, yankeedog said:

I am not liking the arch in that spring. It seems to me that the double bend at the base near the screw hole is what is supposed to be supplying the tension.If it were my money, I would flatten that spring a bit , making it effectively longer. it would overshoot the cog and not catch.i would do my bending at the base.

You were right @yankeedog. I straightened the spring and now it's running nicely, 270 deg amplitude DU and DD

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  • 1 year later...
On 9/19/2018 at 3:32 AM, Nucejoe said:

:Bravo:

Regar

Back in sept 2018 when mike had posted picture of hole in the jewel,  it must have had trouble opening the picture as it often happens at my neck of the woods and had given him a thumps up for the good amplitude he got.

The pic opened today, I once went down similar path, change the jewel and finished the task. Later widened the rim of the Chaton and popped the damaged jewel out, faced similar damage around the rim of the hole. 

Pivots inflict this kind of damage, when we tighten the cock screw before we properly fit pivot inside the hole, we feel of the balance and that causes the pivot to jump inside the jewel hole, runs and we are happy. As the pivot jumps in, it breaks the jewel as in this picture, this much damage could take couple of such wrong fitting procedure.

Proper procedure is to get the pivot inside the jewel, gently push the cock down with you peg wood, observe the balance oscilation , then comes tightening cock screw. 

Regards

 

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1 hour ago, IFELL said:

Would you say this is a correct end of a mainspring for 613 movement? Seems broken but not sure how it’s suppose to look like.thanks

619CDB70-68FC-46BE-8703-4159B3338AEA.thumb.jpeg.1bbf293a1bbed6ec209ba010563a527b.jpeg

http://blog.watchdoctor.biz/wp-content/uploads/2015/02/rolex.mainspring.jpg 

Spindle is broke, check the above.

Edited by Nucejoe
Your MS is the modern type, looks a bit fifferent.
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