Which is the regulator adjustment on this st3620?

[Bill2024]

I just got a timegrapher and wanted to experiment with the effects of regulating this movement. However I’m not sure which of the two levers on the balance is actually for regulating; is it the one on the left or right in the picture?  They both seem perilously close to the hairspring!  Also there is no indication of fast/slow like I’ve seen on some movements. 

thanks

Bill

[caseback]

The right one holds the stud. Moving it will change the beat error. The left one will change the rate.

[mbwatch]

For fast/slow, moving the regulator arm away from the hairspring stud increases the rate (by making the spring effectively shorter) and moving it towards the stud makes it slower. So the farther apart those two arms are, the faster the watch.

But the movements are really tiny. One tenth mm of movement might change as much as 40 or 50 seconds per day. And the stud carrier is even more sensitive for beat error. Barely perceptible movements cause large changes.

[Bill2024]

32 minutes ago, caseback said:

The right one holds the stud. Moving it will change the beat error. The left one will change the rate.

Thanks that’s very helpful

28 minutes ago, mbwatch said:

For fast/slow, moving the regulator arm away from the hairspring stud increases the rate (by making the spring effectively shorter) and moving it towards the stud makes it slower. So the farther apart those two arms are, the faster the watch.

But the movements are really tiny. One tenth mm of movement might change as much as 40 or 50 seconds per day. And the stud carrier is even more sensitive for beat error. Barely perceptible movements cause large changes.

Thanks - I’ll do some experimenting to get a feel for it. According to the timegrapher the beat error is pretty good I think; somewhere between 0 and 0.3 depending on position. The rate varies a fair bit more at around +16s dial up to -2s dial down. 

What is the correct tool for making the adjustments: screwdriver? pegwood?

[mbwatch]

28 minutes ago, Bill2024 said:

What is the correct tool for making the adjustments: screwdriver? pegwood?

Anything you're comfortable with. Some regulators move easily and others take some force to overcome initial friction. I like pegwood (cut to a flat "blade") because it won't scratch and is less likely to damage a regulator pin if I slip. I don't find it easy to keep a screwdriver in good contact without it sliding around; feels dangerous to me. But plenty of people do it that way. On some regulators, a closed pair of bigger tweezers makes a good "V" to nest in and push, the ones that want to move more smoothly and readily are easier to do with tweezers. If pegwood, avoid the kind that is sorta crumbly and will shed little bits into the movement.

If you are really hoping to dial that movement in, bringing your dial up/dial down rates closer together is the place to start. But that wouldn't be done by regulation; a significant difference there in rate and especially in amplitude is a good indication that one of the balance pivots is less clean than the other, or there is an unequal amount of oil on the balance jewels.

[canthus]

As a novice, take care when adjusting the beat error arm.  Normally the regulator pins (arm) will follow the movement of the beat error arm and so maintaining the regulator setting.  However, sometimes only the beat error arm moves, and if this is towards the regulator arm it can kink the hairspring between the stud and the regulator pins, as the regulator pins have trapped the hairspring.  Moving it away, from the regulator arm, is unlikely to cause any problems unless the movements are large.

[Bill2024]

26 minutes ago, mbwatch said:

Anything you're comfortable with. Some regulators move easily and others take some force to overcome initial friction. I like pegwood (cut to a flat "blade") because it won't scratch and is less likely to damage a regulator pin if I slip. I don't find it easy to keep a screwdriver in good contact without it sliding around; feels dangerous to me. But plenty of people do it that way. On some regulators, a closed pair of bigger tweezers makes a good "V" to nest in and push, the ones that want to move more smoothly and readily are easier to do with tweezers. If pegwood, avoid the kind that is sorta crumbly and will shed little bits into the movement.

If you are really hoping to dial that movement in, bringing your dial up/dial down rates closer together is the place to start. But that wouldn't be done by regulation; a significant difference there in rate and especially in amplitude is a good indication that one of the balance pivots is less clean than the other, or there is an unequal amount of oil on the balance jewels.

Thanks very much for taking the time. I don’t know what the oil situation on the movement is at the moment as it is a new movement which I haven’t tried to strip down and lubricate yet (waiting for my oils to arrive). Thought I’d just do some experimenting and take some readings before trying to strip down and reassemble the movement - assuming it runs at all when I’ve finished with it!

2 minutes ago, canthus said:

As a novice, take care when adjusting the beat error arm.  Normally the regulator pins (arm) will follow the movement of the beat error arm and so maintaining the regulator setting.  However, sometimes only the beat error arm moves, and if this is towards the regulator arm it can kink the hairspring between the stud and the regulator pins, as the regulator pins have trapped the hairspring.  Moving it away, from the regulator arm, is unlikely to cause any problems unless the movements are large.

Interesting - I’ll try and be careful!

[tomh207]

Always a good idea to take a baseline set of readings before starting on a running watch. Then you know for sure if you made a mistake somewhere.

 

Tom