Omega constellation 751 steady losing 10 min/day

[noirrac1j]

Hello,

I think I know whats going on. But need some input on this before I do anything. The omega 751 constellation is losing 10 minutes a day within an hour consistently. Its not stopping, and its not something in the gear train. I replaced the mainspring...still not right. I suspected the cannon pinion and pulled it out. Gave it too hard of a wack and its no good. Bought a Brand new genuine replacement from J borel and same thing!!. I am trouble shotting now. Removed day date mechanism and replaced hands. Ran fine for 35 minutes. At end of an hour I checked and....10 minutes off. Can a new cannon pinion need tightening? These little buggers are nearly 50 bucks a piece and I hesitate to tighten it. I have the right tool, and I know I simply hit the last one too hard and the dent was very deep. What else do you guys think it could be?

Sent from my SM-G925T using Tapatalk

Edited April 11, 2016 by noirrac1j

[bobm12]

Hi Joe,

Did you checked that jewels are absolutely clean. Sometimes it has happened to me that after putting everything through the cleaning machine I assume it is clean and when I go inspecting with high magnification, there I find still some crust stuck to them so,,,back to pegging and washing! Sometimes -- I got this from Geo -- I simply leave the jewels/parts in Ronsonol for a few hours/days and clean again.

Also, did all gears mesh properly? It may be "skipping" a tooth or something. Bent/worn pivot or even a bent plate? Main spring tension OK? Over/under lubrication or wrong/contaminated oils or on wrong/forgotten spots? Sometimes even when we are so meticulous, an interruption or distraction or whatever makes us make the mistake we so much tell others not to make!

Cheers,

Bob

PS. It just happened to me the other day, working on another Seiko, I had assembled the keyless works and done most everything but forgot to clean the balance pivot jewel on the plate...I realized that when I cleaned the balance cock jewel and turned the movement to get its counterpart. Needless to say, I had to disassemble most of the watch again to get at it! In my case, it seems like my age is playing its tricks again with my watches!

[WillFly]

The last time I had this loss rate on a movement it was dirt and over-lubrication, pure and simple. Worth a check. Best of luck.

[jdm]

14 hours ago, noirrac1j said:

I am trouble shotting now. Removed day date mechanism and replaced hands. Ran fine for 35 minutes. At end of an hour I checked and....10 minutes off. 

What the timegrapher shows ?

[noirrac1j]

Well now I've lost the incabloc spring for the main plate.....

[noirrac1j]

One things after another with this watch. Now I have to order another Incabloc shock spring for the main plate. it's starting to wear an evil grin....I won't put up with this much longer:

[anilv]

Hi Noirrac1j,

On 4/11/2016 at 9:45 AM, noirrac1j said:

is losing 10 minutes a day within an hour consistently

Is the watch losing 10mins an hour or 10mins a day? Sorry I really don't understand the above statement.

If it's 10mins an hour then something is very wrong..if dirt was causing it to run slow, the amount needed to slow a watch 10minutes an hour would probably stop it cold in a few hours. If this was a movement which is available at different bph (eg higher beat) I would guess someone fitted a wrong part. But as the 751 is only available in 19800bph this is not so likely.

I'm not too familiar with this family of movements but I know constellations are higher chronometer grade. Do they come in different jewel counts? An escape wheel with capped  jewels may have pivots designed specifically to work with cap jewels whereas an escape wheel with normal open jewels may have different types of pivots.

As Bob and Will stated, go thru the movement again, paying attention to the pivots, worn barrel pivots are frequently overlooked and can cause a lot of poor running issues. Pinions can come loose, check that they are firmly affixed.

If you're worried about the cannon pinion, as long as there is resistance when you set the hand and the pinion does not rise up on the centre wheel that it should be fine.

I would also consider hairspring or balance issue. Does the watch loses the same amount if you lay it face down? Perhaps someone replaced the hairspring with an incorrect one.

 

Finally, what was the history of the watch... ebay or similar watches are risky as you don't know what has been done before.

Was it running before you took it apart?

 

Anil

 

[noirrac1j]

Hello Anil,

I took the jewels out as suggested by my esteemed watch maniacs and promptly lost the incabloc shock holder for the plate. It just flew away. I ordered another one...but I want to blame ALL OF YOU that said it was dirt because it wasn't! I'm not really serious, just venting is all...

It was indeed the cannon pinion which was brand new, so just in case someone thinks "oh, it is new, I shouldn't have to tighten it" well I did have to. The original cannon pinion I hit with my tool so hard I made too large of a dent and it was no longer going to fit in position...hence the new one (original omega in the package) from Borel. I can't put the calendar works or dial back until a receive the replacement incabloc spring.

 

Warmest regards to my fellow members that replied.

JC

 

 

[anilv]

Noirrac1j

Glad it worked out!

Anil

[noirrac1j]

1 hour ago, anilv said:

Noirrac1j

Glad it worked out!

Anil

Yes it worked out Anil. The problem with the cannon pinion was a characteristic, distinct block of lost time within an hour, which is what I was trying to describe. So, when I would set the watch to 8pm, if I went back at 9pm, the watch would read 8:50. If I let it run till 9:30pm, it would read 9:20 and so forth. The problem didn't seem to be anything other than the cannon pinion. I originally overhauled this watch last year and I think I did a good job, so it wasn't over oiling or dirt--although any of those things were a plausible possibility (thanks @WillFly and @bobm12)

 It was running fine until one day I realized it would run 10 minutes late when I wound it and set it down, wore it, whatever. When I opened it up and checked everything seemed fine. The sweep hand is wobbly (it was always kinda bad) so that is going to need replacing. Now the incabloc spring flew off into the Nether regions of my apartment...gone. I am now awaiting a new spring and sweep hand, but the cannon pinion problem is fixed. The settign action is firm but that's fine with me. 

 

J

[bobm12]

Excellent work Joe! I'm glad the problem is solved and new spring is in the way. It sucks that you can't wear it for just that little spring. I feel your pain!

Cheers,

Bob

[WillFly]

Glad you sorted it, Joe - and I hope my dirt obsession didn't waste your time!

[noirrac1j]

Ok I got the spring upper incabloc.....cannot get it to go in. Does this look wrong? I think its too big, but I ordered it via the J Borel movement material database.....

Sent from my SM-G925T using Tapatalk

[Marc]

Looks a bit big to me

[noirrac1j]

Hello,

Yeah I thought it looked big to me as well. I managed to secure the closed end onto the plate, but the open ends of the lyre won't close. I read that sometimes the entire unti needs to be removed or at minimum pushed up with a staking set before the incabloc spring can seat properly. Am I doing something wrong or is the spring the wrong size. I guess I could send it back? I need help!!

Sent from my SM-G925T using Tapatalk

[noirrac1j]

Help!

Sent from my SM-G925T using Tapatalk

[bobm12]

Hi Joe,

I'm not sure but sometimes parts are catalogued wrong so you get the wrong part inside the "right" bag! I would talk to Borel directly. I've always gotten good service and solutions from them.

From your pictures I think you have a size bigger than what it should be: too "fat", but also it is looks as it is "shorter" too? Maybe it is the angle of the pic itself? As I said, talk to Borel...maybe you don't even need to send that part back...which is ridiculous for such a tiny and somehow inexpensive part...I think.

Cheers,

Bob