ETA 2782 problem

[IFELL]

Hi all,

I am repairing this ETA 2782 (time, central second hand, date, rapid day change, automatic winding) and I have come across a problem.
The watch was completed and in testing all went very well until the phase of changing date number.

From my observations it seems that when the day changing wheel reaches the date disk, it is too hard for it to move it one date further.

The resulting situation is that the watch is running (central seconds hand is moving), but the time itself stops around 23:30 and the hour and minute hands stop moving. Here are some pictures:

Now my personal thought is that the problem lies with central wheel and cannon pinion. Here, those two are fitted together (see pics below) and I suspect the cannon pinion that is slips at the point when the date changing wheel's pusher reaches the date disk. I think that is does not have enough grip on the central wheel to be able to hold the whole mechanism and so just slips, causing the minute and hour hands to stay still while second hand is moving freely. 
The question is then: how to fix this?

[Marc]

It does sound like a slipping cannon pinion issue, when you set the time how much resistance can you feel at the crown? I'm guessing that it's pretty loose.

You can tighten these if you're careful but it can be a bit hit and miss. The wheel is in two parts, a hub and a rim, with the rim held onto to the hub with 3 tabs. If you'rs careful ou can separate the two parts, give each tab a gentle twist out of the plane of the rim (not too much) and then reassemble. It is fiddly and isn't always successful but if you're pushed for the part it's worth a try.

The best route though is to replace the wheel altogether. You need to make sure that you get the right height though. Cousins have 2 of the 3 height options in stock for £7.25 +vat.

[rogart63]

47 minutes ago, Marc said:

It does sound like a slipping cannon pinion issue, when you set the time how much resistance can you feel at the crown? I'm guessing that it's pretty loose.

You can tighten these if you're careful but it can be a bit hit and miss. The wheel is in two parts, a hub and a rim, with the rim held onto to the hub with 3 tabs. If you'rs careful ou can separate the two parts, give each tab a gentle twist out of the plane of the rim (not too much) and then reassemble. It is fiddly and isn't always successful but if you're pushed for the part it's worth a try.

The best route though is to replace the wheel altogether. You need to make sure that you get the right height though. Cousins have 2 of the 3 height options in stock for £7.25 +vat.

Best way i have used to tighten the cannon pinion on this is to use a staking tool.  A rounded punch and give the center of the wheel a slight knock. Making the hole for the minute pinion a little tighter. Best is to replace the complete unit. 

[rogart63]

Have you checked the date driving wheel. Check that the springloaded pushers is moving as it should. 

[clockboy]

I have not worked on this calibur but is this wheel sitting correctly I can not see what the teeth are meshing with.

[IFELL]

36 minutes ago, clockboy said:

I have not worked on this calibur but is this wheel sitting correctly I can not see what the teeth are meshing with.

 

They are meshing with the hour wheel (good view of it in the very first picture)

[IFELL]

3 hours ago, rogart63 said:

Have you checked the date driving wheel. Check that the springloaded pushers is moving as it should. 

Thanks for this input. I'm pretty sure that it is moving as it should but will make another test before purchasing the new part.

[IFELL]

4 hours ago, Marc said:

It does sound like a slipping cannon pinion issue, when you set the time how much resistance can you feel at the crown? I'm guessing that it's pretty loose.

You can tighten these if you're careful but it can be a bit hit and miss. The wheel is in two parts, a hub and a rim, with the rim held onto to the hub with 3 tabs. If you'rs careful ou can separate the two parts, give each tab a gentle twist out of the plane of the rim (not too much) and then reassemble. It is fiddly and isn't always successful but if you're pushed for the part it's worth a try.

The best route though is to replace the wheel altogether. You need to make sure that you get the right height though. Cousins have 2 of the 3 height options in stock for £7.25 +vat.

Thanks yes the time setting is pretty smooth.
Fortunately this is 2.2mm so I will order from Cousins.

Thank you all for the inputs  Much appreciated.