So I got a relatively inexpensive Dynamic. It's in pretty good shape, but the seconds hand is moving in a stuttering fashion. Oddly, it has been keeping accurate time over the past few hours. Video below shows the hesitation. What can I expect to have fixed on this?

Many Thanks!

 

I'm going to keep her running and see how it turns out. Definitely taking it in to a watchmaker.

 

Indirect seconds stutter. The tension on the spring can be adjusted when serviced.

 

Dennis is correct - with the design of this indirect seconds, there is a friction spring that rests on the sweep seconds pinion, and it provides some drag to keep the hand from stuttering. You simply have to balance the tension so that it's enough to prevent the sutter, but does not put so much drag on the movement to affect the balance amplitude significantly.

Sometimes they can be adjusted to remove the stutter, but I often end up replacing them because they have been mistreated by watchmakers before the watch gets to me. One of my pet peeves in fact...that along with not putting the right screw in the right place...but that's another post sometimes down the road...

Here is one on a recent service that shows the problem from each side of the spring:





You can see a dimple in the rounded portion of the spring that rides on the sweep seconds pinion. In fact this area should be perfectly flat, and this dimple is from a lazy watchmaker who pressed on the seconds hand without protecting the spring. This dimple makes getting the tension correct more of a challenge, and if I see one like this I just replace it if I can't flatten out the dimple to make it smooth again.

When I place the movement in my dial side movement holder with center support, and press the hand on using my hand press, I insert a piece of old mainspring between the pinion and the friction spring, as shown here:



This allows the pinion to be supported, and prevents distortion of the friction spring.

In any case, it should be an easy thing to correct on your watch.

Cheers, Al

 

Wow, a quick, thorough and educational response. I will keep my ear open for my watchmaker on this issue. Thanks!

 

Damn Al, can we designate you as "Official Illustrator" for all explanations?

 

I had the same issue with my black waffle seamaster. My watchmaker gave me a similar (but less illustrated) explanation. He also said that it is more likely to happen when the dial is face up, because of the weight on the spring, and doesn't impact on accuracy.

 

Well this was a useful thread to find. My Omega geneve cal. 601 has been stuttering after coming back from the watchmaker to replace the mainspring

it is keeping the best time it ever has, but has this occasional irregularity to the seconds hands

I’m assuming this can wait until it’s due for a full service

 

The 600 series is a little different, because they don't have to save room on the base movement for the automatic winding system. So it has a spring that lifts the sweep seconds pinion in a jewel that is fitted to a small bridge - spring shown at the red arrow:



Bridge is installed here:



Rarely have to replace the springs on these, but the spring likely needs to be adjusted to have a bit more friction. This isn't a problem that requires immediate attention, but if it was just serviced then personally I would want it to be right.

 

Thanks so much for the information, that reassures me. This was just a repair job done by a friend of a family member in Paris (A horologist but not my usual watchmaker). However, it is frustrating that a simple check and adjustment was all that was needed.

we all miss the odd thing though I guess

I’ll get it fixed the next time I see my usual watchmaker for another job. What worried me was that it was going to damage the movement.

 

Just thought I'd mention (for the purposes of other people who are looking at this thread with the same problem) that I took this to my watchmaker and he literally fixed it in a few minutes while I was in the shop, easy as that.

Don't know why I got into such a fit about it

Oh well, thanks for your info @Archer