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Sauterelle à lune perpétuelle 2M

Sauterelle à lune perpétuelle 2M

Andreas Strehler will present his world record watch, the Sauterelle àlune perpétuelle 2M at Baselworld 2015.

At BaselWorld 2014, Andreas Strehler presented his Sauterelle àlune perpétuelle with a practically perpetual indication of the phase of the moon. Now, he has built an even better moon phase. On 20th July 2014, right on time for the 45th anniversary of the moon landing, the first watch was completed.

If the Sauterelle àlune perpétuelle had to be corrected every 14’189.5383 years by one day, Andreas Strehler managed to improve this value significantly.

The Sauterelle àlune perpétuelle 2M needs such a correction only every two million years – hence the designation 2M. To be quite precise, the correction is needed every 2’060’757 years.

Based on calculations made by Professor Robert Baggenstos, Andreas Strehler designed a completely new gear train for the 2M. Professor Baggenstos has calculated the ratio and Andreas Strehler has turned these calculations into a gear train. For this, the available space inside the movement had to be reallocated and the position of the balance had to be adapted. All this was done while the size and design of the present Lune Perpétuelle remained unchanged.

In spite of the improved precision of the moon phase indication, Andreas Strehler managed to keep the number of components the same. Like the Sauterelle àlune perpétuelle presented in Basel last year, the Sauterelle àlune perpétuelle 2M only needs four components to achieve this feat.

The Sauterelle àlune perpétuelle 2M by Andreas Strehler is therefore, the most precise phase of the moon ever built. And by some margin: About 2.045 million years. This is also an official Guinness World Record and the watch can be found in the eponymous book of records.

Technically, the Sauterelle àlune perpétuelle 2M is based on the Sauterelle which Andreas Strehler presented last year. Like the Sauterelle, the 2M has Andreas Strehler’s unique remontoir d’égalité. This provides a constant supply of energy to the escapement.

The Lune Perpetuelle 2M is a further example of Andreas Strehler’s technically mature constructions. In the words of the Jury of the Prix Gaïa: “His minimalistic movements conceived like true living organisms.”

Using only four components, Andreas Strehler achieves the precision of his moon phase indication by driving it continuously instead of switching it forward once a day. By a clever combination of internal and external toothing as well as by the use of prime numbers for the numbers of teeth in the gear wheels, Andreas Strehler could represent complex fractions by gear wheels having integral numbers (half a tooth on a gear wheel does not work in horology – or in general, for that matter).

All this leads to the unprecedented precision of the moon phase indication of the Sauterelle àLune perpétuelle 2M.