Date wheel shenanegans on ETA 2836

[JeremyLaurenson]

My date wheel keeps popping up and for the life of me I cant figure out what I am doing wrong...

 

[Klassiker]

If you fit the day disc it will keep the date disc in place.

[Jon]

1 hour ago, JeremyLaurenson said:

My date wheel keeps popping up and for the life of me I cant figure out what I am doing wrong...

Here's a set of pics taken in order. A tooth or two have to be under the jumper spring plate at all times to stop the date wheel from being able to come up. If that is not the case, then I can only assume it is not the correct wheel or jumper spring plate. 

If the plate is covering at least one tooth during the date change, then this problem couldn't happen

 

Edited February 17 by Jon

[GuyMontag]

I pulled up a video from when I serviced a 2836-2 and I don't see anything different in your video vs. mine. I slowed my video way down in VLC and paused and took a screenshot while the date wheel is advancing and in the image it looks like there is an instant where the Date Jumper Retaining Plate is NOT covering any of the Date Wheel teeth, or at least not that I can see.

One thing that does looks slightly off is that right before you start to change the date, the Skipping Double (spring) is sitting between the teeth, where it's supposed to be, but the date shown right next to the Stem is not centered over the stem. Are you sure this is the correct Date Wheel? Did the quickset function work prior to servicing?

 

 

Edited February 17 by GuyMontag

[Klassiker]

I just put one of these back together last week, and the date jumper maintaining plate no.5295 is exactly the same shape as yours, so you have the right part fitted. There is indeed that intermediate position where the teeth can slip through the plate as is happening in your video. I might have been a bit hasty with my post above, though. It does seem strange to rely on the day-disc to hold the date wheel down. I assembled both then tested them together, so I can't be sure. I still have the watch on test, so if I get chance in the next few days I'll remove the dial and day disc, and see what happens.

[GuyMontag]

47 minutes ago, Klassiker said:

I just put one of these back together last week, and the date jumper maintaining plate no.5295 is exactly the same shape as yours, so you have the right part fitted. There is indeed that intermediate position where the teeth can slip through the plate as is happening in your video. I might have been a bit hasty with my post above, though. It does seem strange to rely on the day-disc to hold the date wheel down. I assembled both then tested them together, so I can't be sure. I still have the watch on test, so if I get chance in the next few days I'll remove the dial and day disc, and see what happens.

The day disk doesn't need to be present to keep the date wheel in place. I think it's common practice to lubricate the teeth of the date wheel by applying your oil to the skipping double spring and then advancing the date to transfer the oil to the date wheel teeth, repeating as you go.

Edited February 17 by GuyMontag

[Marc]

This is a 2836 that I have just pulled from my projects box and as with the example above from @GuyMontag there is a moment during the date change when the teeth line up perfectly with apertures in the retaining plate, however, the point at which the jumper spring starts to flick the wheel into place is just before the point of alignment (for want of a better description) and so the wheel powers through the alignment without dislodging. I had to hold the date wheel in this position to take the photograph.

What is interesting here is that we seem to have a variety of different shapes of retaining plate, and the one shown by @Jon doesn't have the cut outs that align with the teeth at all, so with his example it is impossible for the wheel to jump out.

It may be that something is lifting the date wheel on @JeremyLaurenson's watch such that the teeth are being pushed up against the underside of the retaining plate just enough that as the teeth align with the cut outs they are pushed through.

I'm guessing that the date wheel is for a 6 o'clock date window rather than a 3 o'clock window, hence the orientation of the numbers and the misalignment at the stem (the alignment of the 13 is correct for a 6 o'clock window). Is this the original date wheel for this movement? Are the date wheel teeth all in good condition and are any of them bent either up or down compared to the others.

Is the retaining plate original to this movement and this date wheel?

Is it possible that the date jumper spring has a slight twist in it such that it imparts just enough upwards force to the date wheel as it turns that it causes the problem? If it is twisted away from normal such that the bottom edge of the jumper is closer to the date wheel than the top edge it will impart an upwards movement as the wheel turns.

 

[Jon]

17 hours ago, Marc said:

What is interesting here is that we seem to have a variety of different shapes of retaining plate, and the one shown by @Jon doesn't have the cut outs that align with the teeth at all, so with his example it is impossible for the wheel to jump out.

I used a generic quartz ETA movement that I photographed, so the plate wouldn't be the same as this movement, so my bad. I would have thought that the design of all jumper spring plates wouldn't allow the calendar wheel to jump through the gaps, but obviously I was wrong. Seems like a foolish design because if this movement had the same design plate as the one I photographed there wouldn't be a problem.

 

17 hours ago, Marc said:

It may be that something is lifting the date wheel on @JeremyLaurenson's watch such that the teeth are being pushed up against the underside of the retaining plate just enough that as the teeth align with the cut outs they are pushed through.

 

17 hours ago, Marc said:

Is it possible that the date jumper spring has a slight twist in it such that it imparts just enough upwards force to the date wheel as it turns that it causes the problem?

What @Marchas said seems very possible, plausible and probable. Something is pushing the wheel upwards and I can't think of anything other than these suggestions. Is the date driving wheel seated properly? Does the same thing happen when not in quickset, but when you turn the motion work?

[nevenbekriev]

What will happen with dial in place?

[JeremyLaurenson]

When the day disc is in place, it kicks it up anyway.

So, the actual issue was that the Unlocking yoke maintaining plate was not installed right and was not holding down the date indicator driving wheel.

Its back together and working, but now my winding stem no work right, so ill be "practicing" some more

[Klassiker]

Well done with the self-diagnosis and thanks for the feedback!