A question about technical data. ETA 2895-2

[roughbarked]

A watch I've never worked upon.
Have no technical data for.
I've got books and books on watch movements but nothing on the ETA 2895-2.
Now normally this wouldn't faze me but this is a watch that cannot have a single screw undone without finding a way to let the mainspring down and as I often say, look before you leap, I'm wondering if anyone else has a link to an exploded diagram or any information at all. Please.

 

[roughbarked]

Probably no matter. I probably only need better light and magnification.

Serves me right for looking inside a Tag at the kitchen table.

 

[Al J]

Well, this is an ETA 2892A2, with the seconds rearranged on the dial side to be at 6 o'clock in a sub-dial, and this is driven off an extra pinion on the escape wheel. To let the mainspring down, you remove the automatic winding system the way you would on any other 2892, and then let the spring down through the hole in the barrel bridge here:



Often the screws to remove the bridge are coloured differently than the rest of the screws, but if not it's pretty easy to tell what screws need to be removed. The dial side has an extra bridge to support the extended escape wheel:



Just pay attention to the order of assembly when putting it back together. This is a video of the sub-seconds arrangement on the dial side running:

It's all very straightforward, but I'll try to attach a tech guide for you...

Cheers, Al

 

[roughbarked]

I've got it all worked out now thanks very much.
Probably just me elaborating on look before you leap.
I did eventually pay attention to the blue screws but I still didn't trust the layout without having a look first.
This is the thing about watch repair really.
I can pull almost all non-complicated watches apart at the kitchen table or drill your teeth with a jackhammer but it is always wise to not take risks without some sort of calm collective self management..

Here's an image of the light I was using to examine it with.

 

[Al J]

Certainly if you are not familiar with this family of movements, it's better to get a good understanding before you dive in.

I've service so many 2892's and their derivatives, it's pretty much second nature at this point.

Cheers, Al

 

[roughbarked]

ETA do things like go from having the tinest dial side screws to dial side screws that far exceed the bridge screws in length to all sorts of lengths. They become similar after having worked out what goes different with this model.
Yet, one still has to be careful with anything that comes off the 28 line in regards to the setting and yoke lever position when removing and replacing the winding stem. It is so easy to finish the watch and have to uncase it and start again.. Just because you didn't keep notes on where to leave the yoke lever before you remove the stem.
And it is not because I haven't made my own tools to press the set lever button. This particular model wasn't hard in that regard because it looks designed to take the Bergeon 60 screwdriver if you have no other tool.

 

[roughbarked]

Considering that to fill the basket, I'd casually pulled a Seiko 2205 down beforehandand chucked it in the basket witout a blink. Mainly because I have plenty parts and it is easier to see what needs fixing after the watch is cleaned.

 

[Al J]

ETA do things like go from having the tinest dial side screws to dial side screws that far exceed the bridge screws in length to all sorts of lengths. They become similar after having worked out what goes different with this model.
Yet, one still has to be careful with anything that comes off the 28 line in regards to the setting and yoke lever position when removing and replacing the winding stem. It is so easy to finish the watch and have to uncase it and start again.. Just because you didn't keep notes on where to leave the yoke lever before you remove the stem.
And it is not because I haven't made my own tools to press the set lever button. This particular model wasn't hard in that regard because it looks designed to take the Bergeon 60 screwdriver if you have no other tool.

For removing and inserting the stem, just leave it in the winding position, use an 80 screwdriver in the slot to press the button, and you are good to go. Done this for years and never had an issue with the setting getting messed up.

Cheers, Al

 

[roughbarked]

For removing and inserting the stem, just leave it in the winding position, use an 80 screwdriver in the slot to press the button, and you are good to go. Done this for years and never had an issue with the setting getting messed up.

Cheers, Al

How many years?
I'm talking about ETA models from a lot of decades and from before they put the slot for the screwdriver.
I simply had never seen this particular subsecond model before. Must admit that at first it threw me for a bit.
and I'm probably recalling things like the Tissot 794 with the day date, had to be tipped upside down to put the stem back in.

 

[Al J]

How many years?
I'm talking about ETA models from a lot of decades and from before they put the slot for the screwdriver.
I simply had never seen this particular subsecond model before. Must admit that at first it threw me for a bit.

For any 28XX series ETA movement, just using the 80 screwdriver works. The problem usually comes from pushing the setting lever too far.

If you are saying there are 28XX movements that don't have the slot, well I can't say that I've ever seen one. I've seen the slots on the 27XX series, and if you go back before that to the 24XX series, they used a screw for the setting lever, so it wasn't a push style at all.

But even for calibers without a slot that I service all the time, say Omega 55X, 56X, 75X, and 600 series, I still leave the crown in the winding position, and just push the setting lever with tweezers, and it's not an issue.

Cheers, Al

 

[roughbarked]

For any 28XX series ETA movement, just using the 80 screwdriver works. The problem usually comes from pushing the setting lever too far.

If you are saying there are 28XX movements that don't have the slot, well I can't say that I've ever seen one. I've seen the slots on the 27XX series, and if you go back before that to the 24XX series, they used a screw for the setting lever, so it wasn't a push style at all.

But even for calibers without a slot that I service all the time, say Omega 55X, 56X, 75X, and 600 series, I still leave the crown in the winding position, and just push the setting lever with tweezers, and it's not an issue.

Cheers, Al

Thinking back, there were so many but yes, the slot started appearing in the 2750 if I recall correctly but I was making a pusher that simply pushed it only so far. Probably because the slot wasn't there in the beginning.