Chrono hands reset

[DannyD]

hello dear community,

im currently repairing two mechanical chronos and with both i´ve the same (makes me insane) problems. The Chrono second hands just doesnt reset to 12.

Everytime i reset them they´re stopping  elsewhere but not at 12.00. 

did anyone make the same experience or maybe has some some advise for me?

The Movements are Valjoux 7736 and a pocketwatch "Marnay" by Geismar & Cie (the movement is based on valjoux but modified by G&C)

Is this a common problem or...?

Im grateful for any advise.

 

Regards

 

Danny

 

[jdm]

52 minutes ago, DannyD said:

im currently repairing two mechanical chronos and with both i´ve the same (makes me insane) problems. The Chrono second hands just doesnt reset to 12.

Everytime i reset them they´re stopping  elsewhere but not at 12.00. 

The second hand is lose and move by inertia when stopped istanteously . Be aware, it's easy to crush the tube if you don't put a pin in it while tightening.

BTW, we have a section were members like to introduce themselves before asking questions.

[clockboy]

When setting the  Valjoux 7750 if I remember correctly the hammers need to be pressed in when setting. This is achieved by using a designated chronology movement holder. 
Here is this subject covered in 2015.

Part of this post 

The other movement holder allows you to operate the chronograph as you would when the movement is cased. When pressing on the chrono hands, first run the chronograph, stop it, then zero it, but when you zero it keep pressure on the button and this will keep the hammers pressed hard into the hearts. Now fit the hands and the hearts can't move.

 

[DannyD]

dear jdm and Clockboy, thank you very much for your fast and precious answers. I hope this is the key for success according to the 7736.

Is there anyway to "proof" this alignment problem of the hammer and heart? I mean how can i be sure that for example the second hand is loose or slipping on the arbour...

I´ve already looked for a proper movement holder for the 7736/34 etc but did not find anything. Even at Cousins(UK).

May you have any idea or suggestions where to get those or an alternative? 

I try to follow the instructions and let you know as soo as possible

 

Thank you 

 

 

[jdm]

14 hours ago, DannyD said:

 

Is there anyway to "proof" this alignment problem of the hammer and heart? I mean how can i be sure that for example the second hand is loose or slipping on the arbour...

Mark the seconds wheel and observe the marking staying at the same position reset after reset. If it doesn't, there is another fault , but the hand tube can also be lose.

[clockboy]

Found this.

 

7733_7734_7736.pdf

 

 

[rogart63]

I now a guy that 3 d print holder. I am sure he can help you out. Have his address somewhere . But don't want to flash it out in the open . So if intrested send me a PM . Unfortuanly now pushers on his but maybe he can fix that to. I use a screwdriver or a pegwood. 

[DannyD]

thank you so much for your support, its finally done! 

the tube of the second hand was to lose(never though it could be the tube 

Regards

Danny