Valjoux 72 Minute Recorder Resetting Issue

[Chrono15]

Hello all!

 

I am having an issue with a Valjoux 72. The minute recorder wants to reset to 0 about 90% of the time. The rest of the time it will be exactly 1 minute to the left of 0 always.

Any Ideas? I thought it could have been the minute recorder jumper spring, but I have adjusted it a ton of times with no success. 

 

Attached you will find a photo.

Thanks for any and all insight!

 

[clockboy]

If it is the same procedure as the 7750 the pusher has to be pushed in to engage the cam when fitting the hand. Hence its advisable to use a dedicated movement holder. 

[nickelsilver]

You need to check that when the hammer is down it's in full contact with the seconds heart cam and there is a tiny freedom on the minute cam. The jumper should be centered on two teeth at this moment.

[Chrono15]

7 hours ago, nickelsilver said:

You need to check that when the hammer is down it's in full contact with the seconds heart cam and there is a tiny freedom on the minute cam. The jumper should be centered on two teeth at this moment.

 

Sure. Here is a photo when I am holding the reset hammer in. Let me know your thoughts.

 

Thank you!

[nickelsilver]

In that position check the minute counter has a small amount of freedom with the hammer but not enough to let a tooth go over the jumper.

[Chrono15]

2 hours ago, nickelsilver said:

In that position check the minute counter has a small amount of freedom with the hammer but not enough to let a tooth go over the jumper.

It lets one tooth go over the jumper in that position

[nickelsilver]

12 hours ago, Chrono15 said:

It lets one tooth go over the jumper in that position

In both directions? If so, you will need to shorten the face of the hammer that contacts the seconds cam. If only in one direction you can possibly adjust the jumper to equalize the play, and if you're lucky it doesn't pass the beak of the jumper anymore.

 

The hammer face will need to be polished and flat after retouching, and take just a tiny bit off and check.

[Chrono15]

2 hours ago, nickelsilver said:

In both directions? If so, you will need to shorten the face of the hammer that contacts the seconds cam. If only in one direction you can possibly adjust the jumper to equalize the play, and if you're lucky it doesn't pass the beak of the jumper anymore.

 

The hammer face will need to be polished and flat after retouching, and take just a tiny bit off and check.

I will give it a shot. Only in one direction, However I've adjusted the jumper endlessly to no avail. I'll try the hammer.

[nickelsilver]

4 minutes ago, Chrono15 said:

I will give it a shot. Only in one direction, However I've adjusted the jumper endlessly to no avail. I'll try the hammer.

You adjust the jumper to center the play between two teeth, that's the adjustment. If the play is too much, i.e. you pass the jumper beak in both directions, or making one or the other safe makes the other unsafe, you trim the hammer. If the play is too much no amount of adjusting the jumper will help.

[Chrono15]

On 5/5/2020 at 9:57 AM, nickelsilver said:

You adjust the jumper to center the play between two teeth, that's the adjustment. If the play is too much, i.e. you pass the jumper beak in both directions, or making one or the other safe makes the other unsafe, you trim the hammer. If the play is too much no amount of adjusting the jumper will help.

Thank you. I trimmed the hammer slightly and that did the trick!