Comment arriver à zéro?

[rehajm]

I’ve a Jaeger-LeCoultre Powermatic completed a few weeks ago. It is a beautiful movement and watch. This one was in my price range because the JL dial was covered in oil stains in  a quite un-vintage appeal way. Ugly. I found a quick cheap LeCoultre replacement I believe is lovely but I’ll keep looking for a JL…It’s been running for a couple weeks and I’ve had to adjust the power indicator dial a couple of times. It doesn’t return to zero even when I replace it in what I believe is the maximum empty location. Hopefully third time’s a charm but if not does anyone have a tip on how to sync the indicator to the status of the mainspring? I’m wondering if it’s a replacement spring issue or something….

Edited July 18, 2024 by rehajm

[AndyGSi]

As the futurematic I expect it won't go back to zero once set correctly.

[rehajm]

That’s helpful. In previous wind downs the indicator was stopping with the white zone showing- fifteen to 20 hours of reserve…Now that I’ve run a few times it has reached the red, consistent with the futurematic indication…

[AndyGSi]

Do you know if the dial has been set correctly in the first place?

Edit

What does it show on a full wind?

Edited July 18, 2024 by AndyGSi

[rehajm]

No I don’t know what is correct- I’ve been doing a full wind and letting it settle to a stop, then aligning zero to the window, which is shown in my photo. As it automatic I can wind so the dial reaches full range @ 40 indicated but I suspect since the movement can be wound to slip and beyond perhaps that may be turning the indicator dial out of sync…

Edited July 18, 2024 by rehajm

[AndyGSi]

OK so when it settles to a stop that isn't the zero position.

If you can, you need to let the spring down fully by hand and then set the dial to zero.

Edit

You should be able to prove that there's still power left in the spring when it stops by letting it wind down
normally till it stops and then see what tension is left in the spring when you let it down by hand (if you can).

Edited July 18, 2024 by AndyGSi

[Geotex]

I have an auto movement with power indicator set aside to work on, so I've been reading up on these. I'm sure that there may be variations, but from somewhere I came away with the impression that at least some types will get to their 100% set point and then "slip" so that you don't need to be fully accurate in the initial placement because the indicator dial will adjust itself over the course of some use cycles. But I haven't opened up one of these yet, so I have no clue.

Are these hard linked to the arbor or associated wheels, or is there a clutch interface that gives the ability for the indicator to reach its max point and then "slip" independently? 

[rehajm]

1 hour ago, Geotex said:

Are these hard linked to the arbor or associated wheels, or is there a clutch interface that gives the ability for the indicator to reach its max point and then "slip" independently? 

The little wheel to the upper left of the indicator dial works like a canon pinion. The post it sits on brings the power to the dial side. That train turns the indicator dial until the space without teeth is reached which stops the wheels and the post slips…

[Geotex]

Thanks for the quick answer - this is the next type of complication I plan to tackle so I’m in the info gathering stage.

[rehajm]

Update- It doesn't seem to matter if I set the indicator @ zero with no power or the '40' end with a full wind, the depletion doesn't stop at zero. I have to believe my mainspring is an improper length to sync with the indicator. I replaced the old steel spring with the GR recommended 2593-X but perhaps that wasn't a consideration when sizing. 

Reviewing some of the other listed replacement options for this cal 481 auto some of the options are a bit longer...

[tomh207]

I could easily imagine that this complication is rather like the pre digital dashboard car fuel guages, vaguely accurate on close to a full tank but anything below a quarter tank was “do you think it might be an idea to put some petrol in old chap?”. For my use if it indicates full wind I’d be good to go, any indication that it’s on the low end is time to wind. I wouldn’t care if it was still going whilst indicating zero, it still time to wind it up.

 

Tom

[AndyGSi]

50 minutes ago, rehajm said:

Update- It doesn't seem to matter if I set the indicator @ zero with no power or the '40' end with a full wind, the depletion doesn't stop at zero. I have to believe my mainspring is an improper length to sync with the indicator. I replaced the old steel spring with the GR recommended 2593-X but perhaps that wasn't a consideration when sizing. 

Reviewing some of the other listed replacement options for this cal 481 auto some of the options are a bit longer...

The depletion shouldn't stop at zero as even when the watch stops their's still a small amount of power in the spring.

[nevenbekriev]

Hi, there is absolutelly no mater how You assemble the indicator. If You continue winding the movement, the indicator will sync with the mainspring condition by it'sself. If the indicator reaches 'full wind' before the spring is wound to the end, it will stop moving and continuing winding the spring wil wind the spring to the end, thus syncinc the indicator. If the spring is fully wound but the indicator is not at 'full wind', then continuing winding will move the indicator until it reaches the end and thus get synced. Well if the indicator never gets to '0', this will only mean that the real power reserve is smaller, and it is probably due incorrect mainspring fitted.

PS

Now I see there is 'stopwork' and it is probably connected with the power indicator. If this is the case, then this stopwork must be activated when the power indicator reaches '0' and this is the one and only needed indicator adjustment. But if it is done and still the indicator never gets to 0, this again means that the real reserve is smaller than needed.

Edited July 20, 2024 by nevenbekriev

[rehajm]

28 minutes ago, nevenbekriev said:

Now I see there is 'stopwork' and it is probably connected with the power indicator. If this is the case, then this stopwork must be activated when the power indicator reaches '0' and this is the one and only needed indicator adjustment.

Could you explain this ‘stopwork’?

Edited July 20, 2024 by rehajm

[nevenbekriev]

I believe this is a device that stops the movement when power indicator gets to 0. If the real power reserve is 50 hours, thus the power indicator by the hepl of this stopwork will limit the power reserve to 40 hours by stopping the movement. This works the same like maltian cross barrel arbor limiter on old quality movements Thus, when You start winding, You will imediately have good torque in the train for reaching good amplitude.

[rehajm]

Right. It certainly makes sense there should be power reserve once the indicator reaches 0 and the movement is stopped. It implies the GR replacement spring is too short when the movement stops and indicator only reaches ‘10’ instead of running to zero, yes?

[AndyGSi]

Here are the instructions for the setup of the futurematic and I would have expected that if
yours was setup this way and the spring was too short you wouldn't get the 40 hours power.

I also wouldn't have expected the extra 30mm on a genuine spring (10% extra length) to have made that much difference to the power reserve.

[nevenbekriev]

13 minutes ago, rehajm said:

Right. It certainly makes sense there should be power reserve once the indicator reaches 0 and the movement is stopped. It implies the GR replacement spring is too short when the movement stops and indicator only reaches ‘10’ instead of running to zero, yes?

Well, it is not sure if the power reserve is smaller because the spring is shorter. Is it really shorter? What are the sizes of the original spring and of the generic one?

[AndyGSi]

11 minutes ago, nevenbekriev said:

Well, it is not sure if the power reserve is smaller because the spring is shorter. Is it really shorter? What are the sizes of the original spring and of the generic one?

Original is 290mm and generic is 260mm

[nevenbekriev]

Sorry for hte delay. Not big difference. The 'strenght' (thickness) is the same? If so, then this is not a reason for reduced power reserve. I would check the power reswrve after removing or somehow disabling this 'stopwork'

[AndyGSi]

3 minutes ago, nevenbekriev said:

Sorry for hte delay. Not big difference. The 'strenght' (thickness) is the same? If so, then this is not a reason for reduced power reserve. I would check the power reswrve after removing or somehow disabling this 'stopwork'

Had another look at it and the strength is slightly different but again not enough to make a difference (as far as I'm concerned?).

GR2593A 1.10 x .09 x 260 x 8.5

@nevenbekriev How do you ready this packet? 1.10 x 0.10 x 292?

[nevenbekriev]

I would need to check how many turns of the arbor will be from 0 to full wind with the new spring and with the original. If the new one is thicker and in the same time longer, it may ocupy much more space in the barrel than normal

[rehajm]

For anyone learning from this thread an update on the Powermatic: after a few wind and unwind cycles the reserve indicator has settled into displaying the full wind '40' at a definitive full wind. The movement isn't running 40 hours, closer to a day and a few hours, and the indicator shows a bit less than  '20', consistent with how long it is running...

Upthread there is some conflation of the function of the Powermatic with the JL Futurematic and at this point I'd discourage too many comparisons between the two. The earlier cal 481 found in the Powermatic is a relatively simple automatic compared to the complications of the Futurematic calibers 497, 817.

I do not see any indication of a 'stopwork' function of the 481 movement and believe the synchronization of the power indicator dial is depedent upon the size of the mainspring. I replaced what looked to be the original steel spring with the GR recommended alloy- something I now regret. I'll continue with the research on this one and there are a few 'original' steel springs out there to try, perhaps if a replacement JL dial appears...

 

[everyonesdesign]

If you need to find a mainspring by number of turns in the barrel you can use the mainspring calculation spreadsheet from this page: https://www.vintagewatchstraps.com/mainsprings.php 

Among other things it allows to calculate number of turns based on barrel/arbor size

[rehajm]

3 hours ago, everyonesdesign said:

If you need to find a mainspring by number of turns in the barrel you can use the mainspring calculation spreadsheet from this page: https://www.vintagewatchstraps.com/mainsprings.php 

Among other things it allows to calculate number of turns based on barrel/arbor size

Yes I used that site often and also the spreadsheet calculator what circulates on these boards...As nevenbekriev mentions I should need an original spring as baseline for turns so on to the next challenge on this one...