Amplitude

[jnoble]

Hi everyone, Im new to this forum and I have a technical question and maybe someone could give me some advice or share some tip to resolve this problem. The thing is that I just service an ETA 2836 2. Once the job is finish the movement starts very strong with a good time reading, Beat error 0.6ms, Ampluitude 267 etc. but in a lapse of 24 hours the movement begins to loose time and the amplitude drops dramatically at the point that the movement completly stops.all pivots are in a good condition, not broken or chip jewel. This movement is completly strip, just the train work is in place. Please help.

[Mark]

Did you remove the mainspring when you stripped it?

[jnoble]

Thanks, yes  the mainspring was remove, clean and lubricate.

[Mark]

Checked all the teeth on the barrel? Is there any dirt trapped between any of the teeth?

Same with the great wheel and pinion.

Endshake and side shake of barrel - can the barrel lean over enough to touch any of the wheels - you can check the barrel bridge, is there any scoring under it or under the ratchet wheel?

Hopefully you can see where I am going with this.

 

Also - check the hour wheel teeth, is there a calendar? If so then remove the calendar work and test again, maybe the changeover is causing the problem.

 

Check the free running of the train - e.g. fully assembled without the escapement/balance and manually turn the wheels (with the keyless and motion work assembled) make sure it turns for several cycles of the barrel - slowly and with as little pressure as possible, if the wheels become erratic then remove the motion work, then work your way all the way to the barrel checking all the teeth and pinion leaves to make sure no grit or dirt is wedged in where it should not be.

 

Hope this helps.

[jnoble]

Thank you so much. Im going to check every detail that you pointed me. I will keep you inform of the progress. Ohhh and by the way let me take a couple of lines to tell you that I admire you as a professional, because you are one of the few persons in the trade that doesnt have fear to pass your knwoledge to help others. In my case I have to turn to a person that is 6,600km apart from me to get any help or advice. Once again thank you so much for your help. 

[Mark]

You are welcome :)

[Geo]

Welcome to the forum jnoble, I'm sure you'll like it here. I look forward to your input in the future.

[bobm12]

Welcome from Florida, USA where the mighty nurse shark lurks in pools and small creeks (they hide very well so nobody really can see them there). :)

 

 

In any case, this is THE forum to hang out in! Great gang here too!

[colinh]

That's a human isn't it?

[Geo]

That's a human isn't it?

Oh Colin, you need your eyes tested. How on earth do you manage to work on watches?? :-)

[bobm12]

Definitely a nurse shark, very distinctive pectoral fins and rear bump, typical of the species!