Twitchy 1570 Seconds Hand

[freddy333]

I am trying to troubleshoot a friend's 1570 that has a 'twitchy' seconds hand. That is, instead of sweeping, the seconds hand twitches or briefly pauses as it circles the dial. The hand is not contacting anything on the dial (including either of the other hands).

A few years ago, I came across an article on someone's website that said this is a common problem with older 1570s which is caused by a bent spring (not mainspring). Unfortunately, I cannot find that article. Does anyone know anything about either the spring (or article) in question?

[RWG Technical]

I would venture to say that the hand twitches on the way down i.e. when the hand is heading the same way as gravity it twitches, but when it's going against gravity its' steady.

Indirect drive and common problem on any indirect center seconds model.

There is a small spring that holds the back of the pinion seconds gear in place, this could be an issue, more likely there is no oil on the spring and pivot and it's got no drag and this is a problem, or there is wear between the driving wheel and the driven pinion.

Could also be beat out of adjustment, or dirty escape pallet stones...

RG

[freddy333]

I would venture to say that the hand twitches on the way down i.e. when the hand is heading the same way as gravity it twitches, but when it's going against gravity its' steady.

Indirect drive and common problem on any indirect center seconds model.

There is a small spring that holds the back of the pinion seconds gear in place, this could be an issue, more likely there is no oil on the spring and pivot and it's got no drag and this is a problem, or there is wear between the driving wheel and the driven pinion.

Could also be beat out of adjustment, or dirty escape pallet stones...

RG

Ok, I know what you are talking about -- the sweep wheel tension spring. But he said the twitchyness started all of a sudden overnight & it seems odd that a spring would suddenly become bent or dislodged that fast, especially when the watch was just resting on a nightstand. But I will definitely check that.

The uneven motion also is unaffected by the watch's position & I already checked the beat (nearly dead-on, amplitude is about 300). Even flat on its back, the second hand is twitchy, so I am kind of leaning toward dirty pallet stones.......or maybe the hand just simply came loose on its pinion?

Thanks RG.