Valjoux 72 Minute-Recording Jumper Adjustment

[j4l3pp]

I have a valjoux 72 with a non-adjustable minute-recording jumper.  How is the jumper tooth position adjusted to the recorder teeth to match the hammer reset position of the minute recorder?

[Mark]

As a test, take the chronograph runner out and then butt the hammer against the minute recording wheel cam. Is there a difference?

Sent from my iPhone using Tapatalk

[j4l3pp]

Yes. The runner is off by 1/2 tooth. It is the same as shown in the picture.

[Geo]

Is it possible to set it by rotating the heart cam relative to the gear?

[j4l3pp]

Heart is screwed to gear. Only one position with no adjustment there.

[Geo]

Is one of the "screws" that the retain the jumper an eccentric?

[Mark]

I need a picture of the chronograph runner and in particular, the finger.

When it is at zero please.

[j4l3pp]

Runner has only one screw and 2 locating pegs. No adjustment there either.

Also, I see your question about the runner, my picture above was taken while the reset lever was being pushed...when pushed, the runner is moved away from the cam on the seconds recorder and the hammer is engaged. The heart lobes are flat against the hammer and there is no other blockage.

Sent from my iPad using Tapatalk

[Mark]

Have you tried unscrewing the hour recording jumper, is the hole elongated to allow adjustment. I am not sure as I don't have one here to check.

There is eccentric adjustment to allow fine adjustment of the hour recording wheel's position but this will affect the position of the teeth in relation to the runner's finger and also if you say the hammer is flat against the cam then it can't be that anyway and so the only adjustment I can think of would be the spring itself.

I know some of these have two screws securing the spring, one to loosen and one to adjust. But yours only seem to have one screw, so I can only imagine the screw hole must be elongated and if it isn't then I can't imagine.

Every one I have worked on in the past have had two screws.

Sent from my iPhone using Tapatalk

[Geo]

I should have asked earlier. Was the watch working OK before, or has happened it since you've serviced it?

[j4l3pp]

Came from a donor Jardur to be used for another project. Will be servicing it next, but noticed the jumper problem and no obvious way to adjust. The screw holes for the jumper are not elongated. It's a curious problem.

[Geo]

I wonder if the hammer has been replaced before you got it. I checked one of my books and it would appear some non-adjusting jumpers had to be set up with very delicate adjustment to the hammer........with a hammer!

Check this out:-

[j4l3pp]

I'm thinking you are right. I have found roughly 2 designs for the hammer. In the picture Mine is on the right, and another one is on the left. Notice the different hammer face angles.

Sent from my iPad using Tapatalk

Edited December 24, 2014 by j4l3pp

[Geo]

The plot thickens. :-)

[j4l3pp]

So...I peened the hammer as shown to line up the jumper only to find that the hammers no longer strike evenly. The seconds hammer strikes first. At this point I had no choice but to re grind the hammer faces with numerous trial fits. I also had to adjust the angle of the minute hammer to line up the jumper again. In the end it was worth the effort. The alignment is now perfect.

Sent from my iPad using Tapatalk

Edited December 26, 2014 by j4l3pp

[j4l3pp]

By the way, thanks for your help and looking up the service information.

Sent from my iPhone using Tapatalk

[Geo]

Very well done sir, that's what I call achievement!

I read about this quite a long time ago, but you are the first I have heard of actually doing it.