Community Stories

Questions about accuracy and power reserve of my recently serviced 2503.52 Railmaster

T
Posts
18
Likes
1
[To get straight to the point, just jump to "day 4" below.]


Hi,
I received my new-to-me Railmaster 2503.52.00 (movement is 2403A) back from service at an Omega specialist who is licensed, but does their work inhouse.
I have warranty in case something is wrong. But since it is my first Omega und only my second automatic watch, I want to ask for your assessment on whether the current state of the watch is normal or what else I should test before contacting the watchmaker. The watch was not working before handing it in for service, so I have nothing to compare it to other than the ETA 2824-2 in my second watch, which is working way better.

The service card gives me the following stats:
+5.1s/d (delta of 5.4s, depending on position)
average beat error of 0.1ms (delta of 0.2ms)
average amplitude of 262° (delta of 28°).
Power reserve is, according to this card, 42 hours, which is 2 hours less than the 44 Omega originally stated.
It says on the card that in order to function up to these specs, one has to wind the crown 20 times every time before wearing it. This is new to me and was not necessary on my other automatic. It does not say whether this is meant only in case the watch has ran to a stop, or also when it is still running when putting it on.

After wearing it for a few days I got the impression that it would run out of steam too soon and also gain more time than expected if I left it to sit for more than just the night. So I documented it over the last four days without resetting the time and here is what I found:

Day 1:
Set to +/- 0s, gave the crown 20 rotations, wore for 11 hours, then put down, checked accuracy and found it kept the +/- 0s.

Day 2:
Put on after 12 hours of sitting, now running at +4s; wound crown 20 full revolutions
Put down after 14 hours, still running at +4s

Day 3:
Put on after 13 hours of sitting, now running at +7s (so, gained another 3s), wound crown 20 full revolutions
Put down after 10 hours, still running at +7s

So far, so good. As long as I wind the crown and put it back on after the night, everything works fine.

Day 4:
Now, I no longer put it back on but let it sit and check the time every couple of hours.
1st check 9,5 hours after putting it down: +8s (so, gained 1s)
2nd check after 13 hours: +10s (gained 3s)
3rd check after 15 hours: +11s (gained 4s)
4th check after 21 hours: +17s (gained 10s)
5th check after 22,5 hours: +20s (gained 13s)
6th check after 24 hours: +23s (gained 16s)
7th check after 26,5 hours: +31s (gained 24s)
Then see on day 5 that the watch stopped running 29 hours after putting it down last.

To my understanding, neither power reserve nor accuracy seem in order.
As I described above, I have little to compare it to, so I would appreciate your feedback on whether this is a clear case and I should just return it to service or whether I am missing something. Thank you in advance!
 
josiahg52
Posts
1,183
Likes
2,199
Where did you read 20 turns is sufficient? I'd triple that with full 360-degree clockwise crown turns. but I'm not familiar with the cal. 2403.

Your observing accuracy in one position. I don't really care about that accuracy unless I want to alternate between wearing it, where it might gain or lose time, and taking it off where hopefully I can find a position where it loses or gains a similar amount of time so that the net is close to zero.

I'm guessing that since it stopped at 29 hours, it wasn't fully wound and this can cause poor timekeeping. For 29 hours, it should've been sufficient, but you observed it in only one position.

Personally, I'd just wear it after fully winding it, then see how it keeps time and if I'm satisfied with that.
 
Jakeys
Posts
447
Likes
1,019
I own the 2504.52 36 mm Railmaster with the 2403B, and had it return from a service by Omega in July this year. To give you a reference, mine has a power reserve of 48 hours (Newer movement revision = better reserve) and in testing I got 48 hours, 45 minutes. In wearing it keeps +4 s/d average. The best position is crown up, which gets around +1-2 s/d, and the worst position is 12 down, which gets +8 s/d and is technically actually out of COSC, but I wouldn't ever store it like that and I'm sure it could be regulated better if I cared enough, which I don't.

Regarding your power reserve, 20 turns is definitely not sufficient to fully wind it. Probably what the service card is saying is that's the minimum wind to get stated accuracy, i.e. below that level of wind you might have a reduced accuracy due to isochronism. A watchmaker would be better placed to speak to that though. I agree with josiahg52, wind it 60 turns minimum for full reserve.

Because you're not winding it fully and letting it sit in one position for long periods, all bets are off with your accuracy. It sounds like while it's wound properly it is keeping great time so I don't think you have anything to worry about.
 
T
Posts
18
Likes
1
Thank you both for your replies.
I got one main inquiry so far:

Both of you say that 20 turns is not enough and I should do 60, which I will in my next test then.
However, you are aware of the fact that I gave it 20 turns before then wearing (and moving) it for over 10 hours and only after that I set it down, right?

The thing is that with my other automatic watch it is enough to give it maybe 5 turns initially as long as then wear it and it will wind itself up in those hours. So much so, that it will then run way over the 40 hours.

That is why I am so confused. I am not really used to having to manually wind at all in order for the watch to be fully wound.

So, this is different with this generation of movements then? Or is the behavior of my ETA really not the norm?
 
T
Posts
18
Likes
1
josiahg52 josiahg52
Where did you read 20 turns is sufficient?

As described, it says so on the service card.

My current storing position is 12 up which, according to chronoscope should be the best position with it gaining 1.9s. However, my watch stand is tilted back by about 30°, so it is not exactly the same.
 
T
Posts
18
Likes
1
Thank you both for your replies.
I got one main inquiry so far:

Both of you say that 20 turns is not enough and I should do 60, which I will in my next test then.
However, you are aware of the fact that I gave it 20 turns before then wearing (and moving) it for over 10 hours and only after that I set it down, right?

The thing is that with my other automatic watch it is enough to give it maybe 5 turns initially as long as then wear it and it will wind itself up in those hours. So much so, that it will then run way over the 40 hours.

That is why I am so confused. I am not really used to having to manually wind at all in order for the watch to be fully wound.

So, this is different with this generation of movements then? Or is the behavior of my ETA really not the norm?
 
Jakeys
Posts
447
Likes
1,019
T thosewhoknow
Both of you say that 20 turns is not enough and I should do 60, which I will in my next test then.
However, you are aware of the fact that I gave it 20 turns before then wearing (and moving) it for over 10 hours and only after that I set it down, right?

The thing is that with my other automatic watch it is enough to give it maybe 5 turns initially as long as then wear it and it will wind itself up in those hours. So much so, that it will then run way over the 40 hours.

That is why I am so confused. I am not really used to having to manually wind at all in order for the watch to be fully wound.

So, this is different with this generation of movements then? Or is the behavior of my ETA really not the norm?

Two things here, firstly the Caliber 2403 will run on 5 turns too, same as your other ETA. The 20 is your watchmaker's recommendation for accuracy, i.e. you may not get acceptable (e.g. COSC) accuracy if the wind is very low, this is called isochronism. It's not Omega specific. Actually, the Caliber 2403 is based on the Caliber 2500 which is itself based on the ETA 2892-A2, though with various modifications such as the co-axial escapement. The 60 is just to start from a fully wound baseline because you're telling us you want to get a good measurement of its power reserve and accuracy, all we're saying is you're not winding it up fully to assess those performance metrics.

Secondly, your watch should run on the movement of your wrist only, yes. And nothing I read in your original post indicates that wasn't happening. But what you did indicate is you never fully wound it, then you wore it somewhat infrequently (It's been sitting still more than it's been on your wrist according to your description) and it did continue to keep working. But then you let it sit for 29 hours before it stopped working, indicating it was still not fully wound.

This is napkin estimating and I am sure a watchmaker will kick me for this generalisation but just to demonstrate, let's assume for a second that exactly 60 turns is 100% mainspring wound and it's completely linear. So you're winding it up 20, so your baseline is 33% wound. You then wear it for about 10 hours, it charges up some indeterminate amount, but then it sits for another 12 hours, depleting it by 28% of mainspring. You then wind it another 33% the next day, barely covering the period it just unwound. As you can see, your manual wind is not actually net winding it very much at all. It may even be less than it unwound while sitting. It's very possible you're continually running it at low wind. It should eventually hit full wind from the rotor but your net manual wind was effectively not much at all, so you were running mostly or only on rotor wind, which lasted 29 hours after only four days. Doesn't seem bad to me! Curious if you were this strenuous on your other ETA watch if it would behave the same way.

My recommendation is that you're overthinking this a bit. Wind it 60+ turns once, or even 80 turns if you really want absolute confidence it's fully wound for your test. Then, just wear it like you always do for a week. Monitor the deviation each day at the same time, and don't wind it again. See if it stays running without winding for a full week of wear, and see if it keeps time to an acceptable standard, i.e. -4/+6 s/d. If the answer to both is yes, breathe a sigh of relief and enjoy it. 😀
Edited:
 
T
Posts
18
Likes
1
Jakeys Jakeys
Two things here, firstly the Caliber 2403 will run on 5 turns too, same as your other ETA. The 20 is your watchmaker's recommendation for accuracy, i.e. you may not get acceptable (e.g. COSC) accuracy if the wind is very low, this is called isochronism. It's not Omega specific. Actually, the Caliber 2403 is based on the Caliber 2500 which is itself based on the ETA 2892-A2, though with various modifications such as the co-axial escapement. The 60 is just to start from a fully wound baseline because you're telling us you want to get a good measurement of its power reserve and accuracy, all we're saying is you're not winding it up fully to assess those performance metrics.

Secondly, your watch should run on the movement of your wrist only, yes. And nothing I read in your original post indicates that wasn't happening. But what you did indicate is you never fully wound it, then you wore it somewhat infrequently (It's been sitting still more than it's been on your wrist according to your description) and it did continue to keep working. But then you let it sit for 29 hours before it stopped working, indicating it was still not fully wound.

This is napkin estimating and I am sure a watchmaker will kick me for this generalisation but just to demonstrate, let's assume for a second that exactly 60 turns is 100% mainspring wound and it's completely linear. So you're winding it up 20, so your baseline is 33% wound. You then wear it for about 10 hours, it charges up some indeterminate amount, but then it sits for another 12 hours, depleting it by 28% of mainspring. You then wind it another 33% the next day, barely covering the period it just unwound. As you can see, your manual wind is not actually net winding it very much at all. It may even be less than it unwound while sitting. It's very possible you're continually running it at low wind. It should eventually hit full wind from the rotor but your net manual wind was effectively not much at all, so you were running mostly or only on rotor wind, which lasted 29 hours after only four days. Doesn't seem bad to me! Curious if you were this strenuous on your other ETA watch if it would behave the same way.

My recommendation is that you're overthinking this a bit. Wind it 60+ turns once, or even 80 turns if you really want absolute confidence it's fully wound for your test. Then, just wear it like you always do for a week. Monitor the deviation each day at the same time, and don't wind it again. See if it stays running without winding for a full week of wear, and see if it keeps time to an acceptable standard, i.e. -4/+6 s/d. If the answer to both is yes, breathe a sigh of relief and enjoy it. 😀
Thanks again.

I will try winding it 80 turns and then see what happens.

Again, my point is that it is behaving so differently from my Fortis (ETA 2824-2).
That watch I can wind 5 turns, wear for 10 hours, set it down and it will run through for the next 40+ hours and keep time within 1 or 2 seconds.
The Omega on the other hand I can turn 20 times, wear for 10 hours, then set down and it will gain 16 seconds in 24 hours and stop running after 29 hours.

So, assuming that everything else is fine mechanically, the self-winding through wearing/moving the watch seems to function at a much lower level in the Omega. This much can be summarized at this point, I would say.
 
Jakeys
Posts
447
Likes
1,019
T thosewhoknow
The Omega on the other hand I can turn 20 times, wear for 10 hours, then set down and it will gain 16 seconds in 24 hours and stop running after 29 hours.

Yeah I take your point, the day 4 test does seem a bit iffy, but it's hard to say without knowing your wear pattern. If you had a particularly sedentary day that day, maybe it had drawn down. You got about 65% of the power reserve in your day 4-5 test. Your accuracy did get crap, admittedly. But while you were wearing it, the accuracy exceeded COSC.

Anecdotally, I am an office worker who drives to and from work, and I take my watch off to work out and when I go to bed and such. My 2403B will definitely keep consistent time (+4 s/d) and stay wound indefinitely just off the rotor action. When I did a pure power reserve test on a full wind, it ran the full required time, which is 48 for my revision. So your expectations of your movement are definitely reasonable, but I'm not 100% convinced you won't see the same based off everything you've said. And it's very easy to overanalyse a new watch, to a degree you wouldn't normally for your other watches. I've been guilty of this myself, I fretted over one position being out of COSC for the first month, then remembered it keeps great time on wrist and got over it.

I'm invested now, please report back how it goes!
 
R
Posts
52
Likes
18
To clarify: COSC -4/+6 is the average over 5 positions. So running +8 in a certain position does not mean anything!
If you have big fingers, maybe 50 winds will do for a full wind, with small finger movements you may need 100 “winds” for a full wind, so wind your watch, when you listen you will hear the mainspring slipping when fully wound, a kind of whisp, whisp sound. Only the you you can determine how many winds you need with your finger movements. Also you can not compare betwwen different watches with a 2892/2403/1120 etc movement. the diameter of the crown makes also a difference, small crowns wind faster with the same finger movements compared to big crowns.
 
Jakeys
Posts
447
Likes
1,019
R RonP
To clarify: COSC -4/+6 is the average over 5 positions. So running +8 in a certain position does not mean anything!
I didn't know this! I thought it had to meet that spec in all five positions.

R RonP
when you listen you will hear the mainspring slipping when fully wound, a kind of whisp, whisp sound.
I've tried to listen out for this before on my Caliber 2403 and I honestly can't hear it, no matter how wound it is, it sounds about the same.
 
T
Posts
18
Likes
1
R RonP
To clarify: COSC -4/+6 is the average over 5 positions. So running +8 in a certain position does not mean anything!
As I said, I am leaving it in position 12H, which according to chronoscope means +1.9s/d. Also, it was not running at +8s, but at +16s after 24 hours.
R RonP
If you have big fingers, maybe 50 winds will do for a full wind, with small finger movements you may need 100 “winds” for a full wind, so wind your watch, when you listen you will hear the mainspring slipping when fully wound, a kind of whisp, whisp sound. Only the you you can determine how many winds you need with your finger movements. Also you can not compare betwwen different watches with a 2892/2403/1120 etc movement. the diameter of the crown makes also a difference, small crowns wind faster with the same finger movements compared to big crowns.
Thanks for the input. As I wrote, the metric given to me and the metric I have been referring to was "complete rotations of the [signed] crown", which is of course independent of finger size. Still, I get what you are saying.

If multiple people tell me they have to manually wind their 2500/2403 for it to keep time and run according to its reserve, then I will have learned that this is a major difference between this caliber and my 2824-2, which has shaped my understanding of automatic movements insofar as I have been thinking they can all be run practically without ever winding manually. The latter has also been my experience with the Rolex cal. 3132 that I used for a few weeks, actually.
 
T
Posts
18
Likes
1
Jakeys Jakeys
I've tried to listen out for this before on my Caliber 2403 and I honestly can't hear it, no matter how wound it is, it sounds about the same.
Same for me, every click sounds equal to my (untrained) ears.
 
Jakeys
Posts
447
Likes
1,019
T thosewhoknow
If multiple people tell me they have to manually wind their 2500/2403 for it to keep time and run according to its reserve, then I will have learned that this is a major difference between this caliber and my 2824-2, which has shaped my understanding of automatic movements insofar as I have been thinking they can all be run practically without ever winding manually. The latter has also been my experience with the Rolex cal. 3132 that I used for a few weeks, actually.

Nobody's saying that. In fact, what I said was:

Jakeys Jakeys
the Caliber 2403 will run on 5 turns too, same as your other ETA

Jakeys Jakeys
My 2403B will definitely keep consistent time (+4 s/d) and stay wound indefinitely just off the rotor action.

The only reason myself and other commenters have brought up winding it more is that you originally said you were winding it 20 times and thinking it was fully wound, and you're also trying to test the accuracy and power reserve, but you don't really know how wound it is so in order for that to be a reliable test, you should fully wind it if you intend to measure it. You don't have to fully wind it for it to work.

You also misinterpreted your watchmaker's card statement that it should be wound 20 times to ensure accuracy. Firstly, that may be an arbitrary way of saying "wind it a bit so it's not really low on power" and secondly, you seem to have taken that to mean every day but I bet it meant for the first time, i.e. if it's stopped, you should give it 20 winds. Not if it's already wound.

To be honest, I expect your watch will run perfectly fine over the next week with no further winds. It sounds like it was running fine already until you weirdly got a hunch that it was not running fine, even though it was. Then you started doing power reserve tests without knowing how wound it was and I think you've worked yourself up - though the accuracy you reported is questionable, but a bit hard to interpret if the watch was nearly out of power and only in one position. Again, by your own admission it was keeping excellent time for several days without full winds. Who's to say it wouldn't have done that if you hadn't wound it one third at night?

Honestly, just wear it for a week and see what it does. I suspect it will run within COSC standards and not stop. But if it does keep bad time or stops with consistent wear, then you will be right to return it for further servicing.

To be clear, the Omega 2500/2403 is an excellent movement, it doesn't need to be babied or constantly wound, it is comparable to period Rolex calibers and superior to period ETA calibers. If yours doesn't perform in normal wear, it requires intervention - which your service warranty will cover.
 
padders
Posts
9,897
Likes
15,545
Without drilling down into the minutiae too much, yes it does sound like your Omega is not self winding as efficiently as it should. I seem to recall the reversers on 2892 based movements (such as the 2500 and similar 2403) can be problematic. If it continues to stop in use then it should go back for revision.
 
T
Posts
18
Likes
1
Thank you for sticking with me, I really appreciate you taking the time.
Online communication can sometimes be prone to leading to misunderstandings. Thanks for clearing some of them up.
I will try to do the same. 😀

Jakeys Jakeys
Nobody's saying that. In fact, what I said was:
(...)
Thanks for quoting again. My statement was meant as more of a hypothetical and I should have worded it better. It was also written with the comment in mind that comparing movements was not useful, even though that was most likely referring specifically to the gear ratio...

Jakeys Jakeys
The only reason myself and other commenters have brought up winding it more is that you originally said you were winding it 20 times and thinking it was fully wound, and you're also trying to test the accuracy and power reserve, but you don't really know how wound it is so in order for that to be a reliable test, you should fully wind it if you intend to measure it. You don't have to fully wind it for it to work.
I never thought it was fully wound after 20 crown rotations. I did however assume it was close to fully wound after 20 crown rotations and 10 hours of wear, which has been my experience with the other watch.

Jakeys Jakeys
You also misinterpreted your watchmaker's card statement that it should be wound 20 times to ensure accuracy. Firstly, that may be an arbitrary way of saying "wind it a bit so it's not really low on power" and secondly, you seem to have taken that to mean every day but I bet it meant for the first time, i.e. if it's stopped, you should give it 20 winds. Not if it's already wound.

Here, I was open to both options I would have leaned towards your interpretation but wanted to take the safe route.
T thosewhoknow
It does not say whether this is meant only in case the watch has ran to a stop, or also when it is still running when putting it on.

Jakeys Jakeys
To be honest, I expect your watch will run perfectly fine over the next week with no further winds.
That would be great and I will let you know.
Jakeys Jakeys
It sounds like it was running fine already until you weirdly got a hunch that it was not running fine, even though it was. Then you started doing power reserve tests without knowing how wound it was and I think you've worked yourself up - though the accuracy you reported is questionable, but a bit hard to interpret if the watch was nearly out of power and only in one position. Again, by your own admission it was keeping excellent time for several days without full winds. Who's to say it wouldn't have done that if you hadn't wound it one third at night?
That's the thing. I would have seen no reason to run the experiment had I not been caught off guard by it running slow last week during what I would say was very normal wearing pattern (without re-winding inbetween, of course). I will see if my observation was correct or not.

Jakeys Jakeys
Honestly, just wear it for a week and see what it does. I suspect it will run within COSC standards and not stop. But if it does keep bad time or stops with consistent wear, then you will be right to return it for further servicing.

To be clear, the Omega 2500/2403 is an excellent movement, it doesn't need to be babied or constantly wound, it is comparable to period Rolex calibers and superior to period ETA calibers. If yours doesn't perform in normal wear, it requires intervention - which your service warranty will cover.
Thanks again!
 
T
Posts
18
Likes
1
padders padders
Without drilling down into the minutiae too much, yes it does sound like your Omega is not self winding as efficiently as it should. I seem to recall the reversers on 2892 based movements (such as the 2500 and similar 2403) can be problematic. If it continues to stop in use then it should go back for revision.
Thank you very much. Getting some idea of what this could be caused by (in case my suspicion is confirmed) was a major hope of mine with this post, so I can have an idea before talking to the watchmaker.
 
R
Posts
52
Likes
18
@padders: The reverser is not problematic on its’s own, it is just a part that works hard during the lifecycle of a watch. For that reason I always replace them by default at service, same like the mainspring, always replaced. It could be after 5 years coming in for service the reverser is working oke, but you do not want to see the customer back in 2 years after the service with an issue on the reverser when it has run an additional couple of years.
So, as trained by a major brand, I always exchange a number of parts by default.

The folks who had their watch serviced by Omega self probably remember the bag with replaced parts that come with the watch after a service. This gives you an idea how much is by default exchanged, just to make sure 95% or more of the serviced watches will make the next 5 years again without an intervention halfway.
 
T
Posts
18
Likes
1
R RonP
@padders: The reverser is not problematic on its’s own, it is just a part that works hard during the lifecycle of a watch. For that reason I always replace them by default at service, same like the mainspring, always replaced. It could be after 5 years coming in for service the reverser is working oke, but you do not want to see the customer back in 2 years after the service with an issue on the reverser when it has run an additional couple of years.
So, as trained by a major brand, I always exchange a number of parts by default.

The folks who had their watch serviced by Omega self probably remember the bag with replaced parts that come with the watch after a service. This gives you an idea how much is by default exchanged, just to make sure 95% or more of the serviced watches will make the next 5 years again without an intervention halfway.
The service was quite extensive and there is a position on the invoice that I would translate to "reversal wheel" from German Umkehrrad. Would that be what you are referring to or is this only part of the reverser?
Also, is there any risk of further damage involved when winding or wearing the watch in case the reverser is not in order?
 
R
Posts
52
Likes
18
Yes, reverserwheel is umkehrrad. No there is no direct danger to the watch other than the in inconvenience that the automatic
winding will be less- or ineffective.
 
13 More Posts...
Sign up or log in to reply...