Vulcain Cricket (S2315A cal.120)

[Klassiker]

In the second close-up, the hairspring appears to me not to pass between the rugulator's pin and boot.

[mikepilk]

21 minutes ago, Klassiker said:

In the second close-up, the hairspring appears to me not to pass between the rugulator's pin and boot.

It looks OK if you zoom in 

[Klassiker]

Yep, that's fine. Not centred, but that's not causing the OP's problem. For some reason I couldn't zoom in with anything like that resolution.

[mikepilk]

41 minutes ago, Klassiker said:

Yep, that's fine. Not centred, but that's not causing the OP's problem. For some reason I couldn't zoom in with anything like that resolution.

Using Google Chrome, right click on the image, then "Open Link in new window".  You can then zoom in to the original pic size

[Ammar]

Hey I'm just wondering could it be the main spring? did you service it? i curious to know what's causing this.

[swiss2k]

@AmmarHello. Yes I did. This is the second time now and I've done it a bit differently this time. 

Personally I think that the power distribution/travel is poor on this movement, and that the balance wheel perhaps should be a bit heavier (to react less to changes). 

This time I cleaned the leaving daylight out of the main spring and the whole power train. Before installing the spring I used Molykote DX paste and applied super thin coat on it (first time I just added some oil on top of the assembled spring inside the barrel in several spots).  To maybe smoot-out/dampen the movement of the spring? 

Judging by the timegrapher, movement runs smoother, but still I notice some acceleration/deceleration with the balance wheel. With lowest 308 and highest 347 amplitude, witch results in -7...+5 s/d.  But those jumps are pretty rare, most of the time it runs around 320-322 and -1...0s/d. 

Maybe if I could record for a longer period of time the changes and fine the time between the pics, that might shine some light where the defect might be. Maybe there is some wear on one side of the pivot? 

Honestly not sure if its worth it, as I spent already quite a lot time fiddling with this watch.

What do you guys think? 

 

 

Edited November 9, 2022 by swiss2k

[LittleWatchShop]

One of my teardowns to compare and contrast.

I would put it together, wear it for a while to see how it performs.  Dont get too worked up about the timegrapher results that you see here.

[swiss2k]

@LittleWatchShopWill do. Thank you for the advice! 

[mikepilk]

47 minutes ago, swiss2k said:

@AmmarHello. Yes I did. This is the second time now and I've done it a bit differently this time. 

Personally I think that the power distribution/travel is poor on this movement, and that the balance wheel perhaps should be a bit heavier (to react less to changes). 

This time I cleaned the leaving daylight out of the main spring and the whole power train. Before installing the spring I used Molykote DX paste and applied super thin coat on it (first time I just added some oil on top of the assembled spring inside the barrel in several spots).  To maybe smoot-out/dampen the movement of the spring? 

Judging by the timegrapher, movement runs smoother, but still I notice some acceleration/deceleration with the balance wheel. With lowest 308 and highest 347 amplitude, witch results in -7...+5 s/d.  But those jumps are pretty rare, most of the time it runs around 320-322 and -1...0s/d. 

Maybe if I could record for a longer period of time the changes and fine the time between the pics, that might shine some light where the defect might be. Maybe there is some wear on one side of the pivot? 

Honestly not sure if its worth it, as I spent already quite a lot time fiddling with this watch.

What do you guys think? 

What do I think? I wonder what you are trying to achieve?

You have achieved chronometer standard from a fairly standard watch movement. I've had few watches which run that well. 

Well done.

[swiss2k]

Hello @mikepilk. Thank you for the kind words.

Maybe I was not clean in my text. What I want is it to stop jumping from 308 to 347 degrees back and forth.   

An interesting observation. When I set the movement dial side up in the timegrapher, amplitude is higher, beat error is lower and overall seems to run much better. 

Magic!

Edited November 9, 2022 by swiss2k

[femtosecond]

Here is the Vulcain Cricket 120 movement technical sheet with parts list for this movement:Vulcain_Cricket_120_Tech_Sheet_OCR.pdf