Watches with regulator dial

Regulator dials stand out at first glance. Where there are usually at least two hands turning in the center of the dial, namely those for the hours and minutes, there is only one hand, the one for the minutes. The hour hand, like the second hand, is a small hand above or below the center. What is this good for and where does it come from?

Nienaber Regulator 2

History of the regulator

First, let’s look at where the term regulator or régulateur comes from. And that’s where it gets complicated, as the term describes a number of different things.

Initially, the régulateur was the person who regulated clocks, initially wall or grandfather clocks with pendulums, and later also pocket watches, as precisely as possible. Electronic time graphers, which allowed rapid regulation, did not yet exist at that time. It was therefore a laborious and time-consuming task.

Soon, precision pendulum clocks with a special arrangement of hands on the dial were also referred to as régulateur or regulator. Typically, the second hand was positioned above the center and the hour hand below. This was intended to guarantee particularly good readability. Observatories and watch manufacturers required high-precision time standards in order to regulate other watches. Even today, such precision pendulum clocks are still produced for enthusiasts, e.g. by Erwin Sattler.

Dial of the Erwin Sattler Classica Secunda 1995 [Source: Erwin Sattler]

Then there are pocket watches that bear the term Régulateur or Regulator on the dial, but have a completely normal dial. This is of course intended to suggest to the buyer that the watch they are buying is particularly precise. A promise that was not kept in many cases, as some of these watches were fitted with the simplest pin lever movements. One example is the watches labeled Régulateur Français, about which I have reported here: Victor Anguenot – again watch movements from France

And finally, there are also wristwatches with a regulator dial. This type of display does not really add any value to wristwatches, but it does offer a little variety if you are comfortable with reading the time. So the answer to the question “Why do you do it?” is simply “Because you can!”.

In wristwatches with a regulator dial, the second hand is usually located below the center and the hour hand above. There are only a few manufacturers who produce or have produced them with the “correct” arrangement, i.e. with the second hand at the top. Erwin Sattler’s Regulateur 1920 or the King Size Regulator by Rainer Nienaber are among them. The “wrong” arrangement with the seconds display at the bottom arises quite naturally with movements for wristwatches if they have a small second hand. In this case, the movement only needs to be modified to display the hours; the seconds simply remain where they are in the normal time display.

Erwin Sattler Regulateur 1920
[Source: Erwin Sattler]

Watch movements with regulator dial

We will now take a look at how a regulator dial can be technically realized in wristwatches using the following movements as examples:

  • Seagull ST1711
    A Chinese automatic movement that is produced with a regulator display as part of a large family of movements.
  • Molnija 3602
    A Russian hand-winding movement with regulator modification.
  • AS 1130
    A Swiss hand-winding movement with regulator modification by Rainer Nienaber.
  • ETA 2824-2 mit Regulator-Modul
    A Swiss automatic movement with additional regulator module.

Seagull ST1711 / TY2807

The ST1711, also known as TY2807, with a diameter of 11 1/2´´´ is the only movement shown here that has a regulator display ex works. The ST17 family with its many different variants is inexpensive and from current production. It is therefore often found in affordable watches, unfortunately often with a design that needs getting used to, as in this example:

PortaS Regulateur PS58I-TY2708-01

You can see from the position of the small second hand that a movement was used here that is actually far too small for the 50.6 x 40.6 mm watch.

The ST17 family has a small second hand by default, so no adjustments for the second hand are necessary for the regulator display. After removal, the movement is quite unspectacular and not necessarily a visual beauty.

Seagull ST1711 / TY2807

The mechanism for the regulator display is located under the large cover plate on the dial side.

It consists of an hour wheel in the center with an additional pinion, a larger intermediate wheel and a small wheel with a pivot for the off-center hour hand at 12 o’clock.

The pinion on the hour wheel and the small wheel are the same size and have the same gearing. This means that the rotation of the central hour wheel is transferred 1:1 to the decentralized wheel. The size of the intermediate wheel is irrelevant for the transmission ratio and can therefore be selected so that the decentralized hour display is positioned in the desired place.

Molnija 3602 with regulator modification

A classic pocket watch movement with a diameter of 16´´´, which has long since been discontinued, but was produced over decades, so that many examples in various qualities can still be found. Unfortunately, the movement has no shock protection.

Regulateur with Molnija 3602

The watch shown here was never made in a watch factory, but was assembled by a watchmaker or ambitious amateur from a case, a customized dial and a modified movement. In other words, a so-called mariage. In this case, he also decorated the movement quite beautifully with thermally blued parts. Similar watches with different motifs on the dial can often be found in online auctions.

Molnija 3602

Two special features immediately catch the eye on this watch with its impressive diameter of 49.6 mm. Firstly, the crown is not at 3 o’clock, but at 12 o’clock. Secondly, the hour display is not at 12 o’clock, but to the left of it at around 10:30. So this is not a regulator in the true sense of the word! The reason for this lies in the way the movement has been modified using the simplest of means. A look under the dial reveals this:

Not a single additional gear wheel was used here! The central hour wheel, which is driven by the minute wheel, was simply relocated from the center so that it continues to engage with the existing minute wheel. This requires only a few modifications to the movement:

  • Drilling a pivot around which the hour wheel can rotate off-center
  • Grinding off the setting lever spring so that there is room for the pivot
  • Milling out the movement plate so that there is space for the hour wheel

If you remove the hour wheel, you can see the modifications more clearly:

This is what the setting lever spring of the movement looks like before machining:

This approach explains why the decentralized hour display is not located at 12 o’clock: the minute wheel determines the possible radius around the central canon pinion for the displacement and there is no space at 12 o’clock because there is a hand setting wheel there.

AS 1130 with regulator modification

A classic wristwatch movement with a diameter of 13´´´, which has also been out of production for a long time. The German watchmaker Rainer Nienaber converted it to a regulator display and decorated it. He also designed the case, the dial and the hands himself. Unfortunately, he is no longer active as a watchmaker and is enjoying his well-earned retirement.

The movement is in the Nienaber Regulator 2 shown above. In contrast to the aforementioned Nienaber King Size Regulator, the Regulator 2 does not have the seconds display at 12 o’clock, but at 6 o’clock.

This movement was also beautified, in this case with decorative stripes and blued screws.

Movement of the Nienaber Regulator 2

When removing the movement, it is immediately noticeable that it has a mounting that makes the movement slightly higher and larger. The diameter thus increases from around 29.3 to 34.8 mm.

The construction principle here is the same as for the Seagull movement shown above. It consists of the hour wheel in the center with a pinion attached to it, a larger intermediate wheel and a small wheel with a pivot for the off-center hour hand at 12 o’clock. Here, too, the pinion on the hour wheel and the small wheel are the same size and both have the same gearing. The size of the intermediate wheel is therefore irrelevant for the transmission ratio, as the rotation of the central hour wheel is transferred 1:1 to the decentralized wheel.

Thanks to the extra mounting, it does not matter which component is located under the new hour wheel on the base movement. It also provides a support surface for the dial. Under the large plate of the mounting there is only a small plate that supports the intermediate wheel:

ETA 2824-2 with regulator module

The ETA 2824-2 is THE Swiss automatic movement par excellence and has been found in watches from many manufacturers for decades. Here it is installed as the basis in a Lorenz Theatro Regulateur.

Lorenz Regulator

The 2824-2 is the only movement shown here that does not have small seconds in its original state, but central sweeping seconds. This makes the conversion to a regulator display somewhat more difficult. In this case, the conversion is carried out using an extra module that is screwed onto the base movement on the dial side. I suspect that it comes from Dubois-Depraz, a Swiss specialist for numerous module constructions. But I’m not entirely sure.

The dial side of the movement with the module looks like this:

Apart from a thin cover plate, there is little to see, but a little more underneath:

The parts responsible for the new hour display are marked in blue. We already know the principle from the other movements:
A pinion on the hour wheel in the center, a wheel of the same size with a pivot for the hour hand and an intermediate wheel that connects the two.

The part marked in green, which ensures that the movement has a small second hand, is also very interesting. There is no connection between the hour wheel in the middle and the small gold-colored wheel below it on the right. This wheel is driven by the third wheel of the base movement. This is located in the next picture at the green marked position on the bridge side of the ETA 2824-2.

To do this, its pivot had to be extended on the dial side so that the small golden wheel could be pressed onto it. From there, it goes via two further wheels to a pinion whose pivot carries the small second hand. A friction spring is attached to this pinion, which ensures that the second hand does not flutter, as it is not in the direct flow of power from the barrel to the anchor. It was therefore not enough to simply screw a module onto the base movement and change the hour wheel; the third wheel also had to be replaced.

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