May the force be (equal) with you

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May the force be (equal) with you - Armin Strom
2 minutes read
Armins Strom's most accessible watch is still a rather sophisticated piece of watchmaking. And not only because of its movement.

Before delving into its inner workings, which have given the Gravity Equal Force its name, let's start by stating the obvious. This is an Armin Strom timepiece indeed. Which means its movement has been designed and built by the brand, which has become a manufacture and uses but their own calibres. Those are strongly reminiscent of the brand founder's style. Mr. Strom practised the craft of skeletonizing so the Equal Force is structured by three apparent and openworked parallel bridges. They lie on top of the conspicuous organs that are the micro-rotor (at 1 o'clock) and the barrel (at 5 o'clock).

Que la force soit (égale) avec vous

It is also eligible to the online configurator the brand applies to its entire range. So if you want yours with a salmon dial, PVD-blue movement and other details of you own device, its easier done than said, and at no extra cost. Even made to measure, this remains the brand's least expensive watch without reneging on its sophistication and design acumen. 

Que la force soit (égale) avec vous

The function that gave the Equal Force its name aims at limiting the variations in the torque delivered by the barrel to the balance wheel. Say what ? Let's put it this way then. The energy of a movement is stored in a spring, housed in the barrel. It's wound by the automatic winding system, or via the crown. As the spring unwinds, it delivers its force through the gear train, which uses it to move the hands and to keep the balance wheel oscillating. The thing is, this force fluctuates as the level of tension within the spring changes. When it's tightly wound, push does comes to shove and the watch runs fast. At the end of the power reserve, it gets soft and the watch runs slow. The idea is to delete these two extremes and remain in a bracket of stable energy supply. That's how the balance wheel oscillates best , which makes the watch accurate.

Que la force soit (égale) avec vous

To obtain a constant force, watches rely on wildly sophiticated devices, fusée and chain, remontoires, exotic escapements, all of which are absolute beasts. It's not common knowledge that there exists a much easier way : keeping the watch at its best winding level. Automatic winding naturally prevents the spring tension from droppping too much, as long as it's being worn. In fact, it would rather overwind the watch, which is the issue the Equal Force directly adresses. 

As soon as the spring reaches a certain level of winding, it gets disconnected from the winding system's micro-rotor. It's never wound at 100%, but rather around 90%. To do that, the manufacture relies on a mechanism that's been in use in watchmaking for centuries : a stopwork, in the shape of a maltese cross. The shape has been modernized but the principle is evergreen. It's got 10 teeth, the last of which has a shape that doesn't mesh with the gear, but actually blocks it. This component prevents the barrel from turning. All there is to do is wait until the energy level drops in the barrel. Then it comes in gear again, starts recharging etc.

Que la force soit (égale) avec vous

It should be noted that once put down, the watch will consume its energy and reach the other end of the problem. During the last hours of the power reserve, accuracy will drop, but who cares, it won't be looked at by then. So this is a constant force of sorts, focused on where it really matters. Rather easy to implement, this complication shows a rare form of intelligence : simplicity for efficiency's sake.

Que la force soit (égale) avec vous

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