6 6r t H - Antoine Martin


6 6r t H - Antoine Martin








Precision: 41

Reach for the stars

After qualifying as a watchmaker, Braun started to develop a unique range with his name on the dial, announcing it to the

world in the year 2000. He didn't want to reinvent the wheel and used well-respected ETA base movements; his domain was

between the movement and the dial. The model names were inspired by Greek mythology, his logo resembled the rising

sun and he was interested in cor:nplications reproducing astronomical phenomena. His 'Eos' indicates the time of sunrise

and sunset throughout the year, displaying it on large dial sectors for accuracy. Eleven versions, available to order, were

made to best suit the latitude where the owner lived. Anther model shows the position o{ the earth in its orbit around the

sun and 'Selene' has what is perhaps the most naturalistic portrayal of the phases of the moon ever achieved in a wristwatch.

Needing further investment to develop his ideas, Braun joined the Franck Muller Group in 2007. Sadly, the timing of

the move could not have been worse, running straight into a transitory recession in the watch industry. The Group had

expanded too rapidly and an acrimonious breakup followed. Braun left the company, leaving his painstakingly created brand

name,'Martin Braun', behind him.

After leaving the Franck Muller Group, Braun created his own movement production company MHO (Manufacture Horlogere

Obwalden) in Alpnach, near Lucerne. And it is here that he developed his remarkable calibre AM39.001, which incorporates

his 30 years of watchmaking experience and takes advantage of the extraordinary precision available in the manufacture of

silicon escapement components. This provided a launch pad for the production of the new Antoine Martin range.

-he rear view here in

iire rcsegold version,

righlights the 17.5mm

irtanium balance wheel

wi".h iiming screws and

precision beat adjuster

The red hand is the

indicator for the 6-day

power reserue. The

unusual skeletonised

three-armed balance

cock maximises the

view of the balance.

Building a bridge

With his love of traditional watchmaking Braun has sought to build a bridge between the period, a century ago, when

he {eels that the most beautiful mechanical movements of the modern era were made, and contemporary production

methods. He wanted to make a feature of the balance wheel and he wanted it to be big and slow. lf one suggests that

this flies in the face of the time keeping theory (which favours high frequency oscillators), Braun replies that large balances

making the traditional 18,000 vibrations per hour (2.5h2) are "more beautiful"; a point that no lover of mechanical

watches would argue with. Using titanium, a light but strong metal, enables the balance diameter to be increased to

17.Smm, which may be the largest ever in a wristwatch. The balance is free-sprung and its rate is regulated by recessed,

gold, timing screws. A micrometre index permits unusually precise beat adjustment, but it is with the escapement of the

new watch that Braun makes the leap from the traditional to the avant-garde.

Although the traditional Swiss lever escapement is the most successful ever made, it involves compromises to

accommodate the limited precision available in conventional technology. ln the newAntoine Martin movement, use of a

silicon escape-wheel and silicon lever with integral pallets enables the escapement geometry to be redesigned to create

the'High Performance Escapement'(HPE, see box). The main advantage of the new arrangement is that in the'stop, go'

world of the escapement, the work done by the escape-wheel in delivering impulse to the balance builds up gradually

when the escapement is unlocked. As a result the energy transferred is increased by around 10 per cent. The low density

of the silicon components, reducing their inertia, is another contributing factor. Moreover the silicon escapement does

not require lubrication, thus increasing service intervals.

42: Precision


The ADAS way

Braun accepts that watch lovers are promiscuous and will not wear the same watch day after

day, so he wanted the Antoine Martin to have a long power reserve. With the efficiency of its

escapement and gearing (see later) the new movement will run {or six days. During this long

running time the power delivered by the mainspring will inevitably decline causing the amplitude

of the balance to drop. Classically, accommodating this problem would require a fusee or a

remontoire; Braun decided to apply his knowledge of aerodynamics to provide a system called

'Aerodynamic Amplitude Stabilisation' (ADAS) to control the balance amplitude.

The balance rim has four small lateral fins protruding from it producing eddies in the surrounding

air as it swings. When the spring is fully wound and its power at a maximum, a spurred lever is

placed close to the balance rim, interacting with these eddies to produce aerodynamic drag.

As the spring unwinds, this lever moves further away and the drag is reduced, maintaining the

balance amplitude as the impulse drops.

Following the well-known principle that 'every little helps' Braun has further paid attention to

the shape of the gear train teeth; a problem also addressed by Patek Philippe in recent years.

ln collaboration with Azurea SA, a Swiss precision-engineering company, Braun has produced a

tooth shape, which increases torque transmission by 5 per cent. He has also modified the way in

which power is delivered from the mainspring barrel to reduce fluctuations as the spring unwinds.

The movement plates and bridges are given an attractive black finish - the precise details of

which are known only to the company which produces it. Stainless steel bushes set in the plates

provide the threads for the screws that attach the bridges. This is a watch on which a skilled

watchmaker, perhaps in the German tradition, has lavished an almost bewildering attention to

detail, but absolutely none of the effort is frivolous, it all contributes to producing a beautifully

designed and long lasting product.

Further information: www.antoinemartin.ch


This detailed view of part of the balance whee

shows the'Aerodynamic Amplitude Adjustment'

to accommodate the reduction in the power of the

mainspring over the 6-day running period. Smal

latera extensions on the balance whee create

eddies in the surounding air as the balance swings.

When the watch is fully wound, fins on the lever

across the bottom of the plcture are brought very

c ose to the balance (b,ut do not touch it) forming

an aerodynamic brake. As the watch runs down

the lever moves away and the effect diminishes

stabilising the balance amplitude.

Precision: 43

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