Jump to content

Chrono hands reset

DannyD

By DannyD
in Watch Repairs Help & Advice

 Share

Recommended Posts

DannyD New Member

DannyD

Posted
Posted

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

 

Link to comment
Share on other sites
jdm Distinguished Member

jdm

Posted
Posted
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.

  • Like 1
Link to comment
Share on other sites
clockboy Distinguished Member

clockboy

Posted
Posted

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.

 

  • Like 1
Link to comment
Share on other sites
DannyD New Member

DannyD

Posted
  • Author
Posted

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 

 

 

Link to comment
Share on other sites
jdm Distinguished Member

jdm

Posted
Posted
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.

Link to comment
Share on other sites
rogart63 Distinguished Member

rogart63

Posted
Posted

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. 

Link to comment
Share on other sites
  • 2 weeks later...
 Share
Go to topic listing


  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • Jon
      What are these Seitz B-Jewels?

      By Jon · Posted

      I picked up a similar amount of these jewels some years ago in a watch and clock fair. Every now and then they come in handy. This week I've got a rubbed in bombe jewel in the balance cock that is cracked and needs replacing. Very handy to have a vintage assortment of these type of jewels!
    • Stirky
      Diagram for 6497 motion works

      By Stirky · Posted

      Thanks Jon.
    • Jon
      Diagram for 6497 motion works

      By Jon · Posted

      Great diagram with the teeth and pinion count. Simple way to reduce the speed of the hour wheel by the 12:1 minute wheel. Genius and yet so simple. Always good to reinforce the principal by what you have done in your drawing. Keep doing that. I had a drawing on my wall for years showing me this which is very similar to the drawing you have done. Here's a formula to work out the beats per hour of a watch movement. The movement's BPH is dictated by the wheel teeth and pinion count and the hairspring being vibrated to the correct BPH by finding the pinning up point on the hairspring using a vibrating tool.  The reason in the formula there is X2 on the top line is because there are two pallet stones.
    • DDean
      Incabloc Lyre Spring & Low Earth Orbit

      By DDean · Posted

      So I just wanted to say "thank you" again.  The angle is the key bit it seems and yes, it did basically just fall, or float, back into position when I got it lined up just right. I had meant to add that now that I see how it goes in, I totally see how it came out in the first place, and that whomever cloned the original movement didn't pay much attention to the fine details around the setting or how it interfaces with the balance cock or the "rings" on the regulator and/or stud carrier arms.
    • transporter
      Commando special

      By transporter · Posted

      Well I’ve never seen the make before and cannot find any info, I haven’t got it just yet it’s been left to me among a 1970’s sea master and a mid size yeoman. But if anyone has any information on this one please feel free to enlighten me, many thanks 
×
×
  • Create New...