ETA 1120 Centre Wheel Problem

[JimXgates]

Good evening folks.

I was asked to repair the above movement. Firstly when it was opened there was a 'paint deposit' in the movement. I cleaned the movement and associated parts and managed to get the watch accurate to +5 secs a day. I was fair chuffed. However, when winding the watch it was extremely difficult and I looked at the movement of the winding wheels. I re-stripped the watch and looked at the centre wheel arbour. It was scored and had excessive lateral movement within the main plate. My question is this, I have ordered a replacement centre wheel do I have to re-bush the main plate. 

I look forward to your responses.

 

Thanks

 

 

[Nucejoe]

If you can still feel a side shake despite the new arbour,  bush the center hole.

Good luck.

 

 

[JimXgates]

Nucejoe thanks for the reply.

Take care.

[jdm]

1 hour ago, JimXgates said:

However, when winding the watch it was extremely difficult and I looked at the movement of the winding wheels. I re-stripped the watch and looked at the centre wheel arbour. It was scored and had excessive lateral movement within the main plate. 

Center wheel is the second wheel that takes motion from the barrel, should have nothing to do with difficulties in winding, so perhaps you mean something different?

[JimXgates]

yeh sorry. When setting the hands its difficult to turn. Would that make better sense.

[Nucejoe]

That has to do with set mech,  which include minute train and canon pinion.

Dose it skip too?

Clean& lube might be all it needs

[watchweasol]

Hi in order to eliminate what could be two problems,  remove the Min wheel and canon pinnion and try the winding and hand set motion again if its still tight look further into the keyless mechanism..   Regarding the second wheel side play in the plate, if as you say its excessive its more likley that the plate has worn and will require a new plate or a bush but in either case both the wheel and plate will require attention,     Tech sheet attached

1876_Eta 1120.pdf

[JimXgates]

Further to this problem. I have cleaned all the parts, removed the cannon pinion and the minute wheel all the keyless mechanism is working as expected. When the cannon pinion is refitted it doesn't click onto the centre wheel arbor and the keyless work is extremely difficult to turn. Should i replace the cannon pinion or am i missing something else.

[watchweasol]

So if i am reading this right every thing is ok untill the cannon pinion is fitted ? . When you say the cannon pinion doesn't click on to the center wheel arbour, Is there no pronounce feel as it seats and when it is fitted it is again stiff to turn the hands.  There should be some friction to allow the hands to drive as normal but not so stiff to make it hard to set the hands . If its too tight then a turn of a broach may help by removing some of the metal insde the cannon, but great care must be taken not to over do it, or alternativley replace the cannon pinion. 

[JimXgates]

Thanks. You are spot on with the 'no pronounce feel' and 'stiff to turn the hands'. I will try the broach first and failing that another order to cousins.

[rodabod]

Worn centre wheel can affect the setting mode as the side-shake causes the canon pinion to constantly sit an an angle. 
 

Go very easy with the broach and repeatedly try it. 

[Nucejoe]

Before broaching put some oil on the arbour, refit canon pinion, it will feel dificult to turn at first, keep turning and it will ease up.

This might be all it needs, if good results, you then should clean and apply grease instead of oil.