Ratchet or arbor slipping

[eccentric59]

I'm currently working on an eBay find (Raymond Weil 2875-ST-00658) with an ETA 2895-2 movement. I stripped it, cleaned it, got it back together with pretty good numbers ( -2 s/d, 260° and a beat error between 0.1 and 0.0). I gave it what I thought was a good wind and let it run for 24 hours. Still running the first day but when I went to wind it again it felt like something was slipping -- that feeling you get manually winding an automatic even when it's fully wound. The watch stopped 10 hours later. When I wound it wouldn't hold much of a wind at all, maybe running for five minutes before it stopped. The thing that looks odd to me is on the barrel arbor there is a space or gap between the squared section where the ratchet wheel sits and the thicker part that is in the barrel. I almost think the ratchet wheel is slipping in that gap. I also checked the ETA technical sheet for the 289x series and the arbor diagrams don't really show any kind of gap or space there. What do you thnk?

[Neverenoughwatches]

3 hours ago, eccentric59 said:

I'm currently working on an eBay find (Raymond Weil 2875-ST-00658) with an ETA 2895-2 movement. I stripped it, cleaned it, got it back together with pretty good numbers ( -2 s/d, 260° and a beat error between 0.1 and 0.0). I gave it what I thought was a good wind and let it run for 24 hours. Still running the first day but when I went to wind it again it felt like something was slipping -- that feeling you get manually winding an automatic even when it's fully wound. The watch stopped 10 hours later. When I wound it wouldn't hold much of a wind at all, maybe running for five minutes before it stopped. The thing that looks odd to me is on the barrel arbor there is a space or gap between the squared section where the ratchet wheel sits and the thicker part that is in the barrel. I almost think the ratchet wheel is slipping in that gap. I also checked the ETA technical sheet for the 289x series and the arbor diagrams don't really show any kind of gap or space there. What do you thnk?

It does look like the square profile of the arbor has worn at the top towards the barrel bridge allowing the ratchet wheel to ride over it when dial up. How does the hole look in the wheel, starting to round off ? Try winding the watch upside down so the wheel drops to what is left of the square. The ratchet hole looks rounded in the corners and i see no purpose for the unusual shape of the arbor square.  Such a pleasure to see very clear macro shots btw, i applaud you

Edited September 30, 2023 by Neverenoughwatches

[eccentric59]

That's the thing, though. If the ratchet wheel was slipping I would have expected most of the wear to be on the softer brass wheel than the steel arbor. And I would have expected the wear to show most in the center of the square, not the corners. In any case I have a new arbor and mainspring coming today so I'll see if they look similar.

[Neverenoughwatches]

12 minutes ago, eccentric59 said:

I would have expected most of the wear to be on the softer brass wheel than the steel arbor. 

That did cross my mind, barrel arbors are pretty hard. Did you try turning your watch over, tapping the case back to encourage the rat wheel to drop onto the more complete part of the square and then wind up from there.

[eccentric59]

It is after a couple of wind cycles that this seems to happen. I can get a decent wind right after assembly. There doesn't seem to be any end shake on the barrel either so if the ratchet wheel is slipping something else is going on.

[rehajm]

Apropos of nothing perhaps- my initial reaction to the in situ photo of the mainspring was- that is a lot of coils. It defies both the not-so-good-rule Rule of Thirds and the a-bit-better-rule 50% Occupancy Rule…

How does a crowded spring behave?

...the movement too new for me to do a quick lookup of the GR size. There are generic replacements avaialble but again, no sizes...

Edited September 30, 2023 by rehajm

[eccentric59]

That is the spring that came with the watch as bought from eBay and the watch itself is circa 2009, so it would be a safe bet that this is the spring from the factory. No other signs that it has ever been opened/serviced before. I would venture a guess that this problem is why they seller sold so cheaply. New spring and arbor have arrived and I'll be fitting them shortly, but will take comparison shots before closing her up. (Her? Are watches inherently male or female?)

[rehajm]

29 minutes ago, eccentric59 said:

 

That is the spring that came with the watch as bought from eBay and the watch itself is circa 2009, so it would be a safe bet that this is the spring from the factory. No other signs that it has ever been opened/serviced before

 

…well that’s a rarity from Ebay …and refreshing- I have to start working on newer watches…