Erwin Sattler Opus Perpetual
Ultra high end precision pendulum clock with spherical moon phase and perpetual calendar
The impressive size, special design and modern aesthetics of this truly majestic precision pendulum clock make it an absolute masterpiece of craftsmanship. The timepiece gives the beholder all the information they could possibly need, lending precious time an attractive face with not only centrally positioned hands to indicate the hour, minute and second, but also an equally beautiful and stylish astronomical trio to show the day of the week, the month and the exact date.
Those who take a closer look at the artfully skeletonised dial will discover a fourth calendar display underneath the axis of the month indicator, with four fields marked 1, 2, 3 and L. Horophiles will know immediately that this is a display for three normal years and one leap year, which tells them that this complex work of art features a perpetual calendar − from which the Opus Perpetual takes its name. Those who adorn their living room or office with this mechanical masterpiece will, theoretically, without any further action on their part, be able to enjoy the intelligently designed calendar mechanism until the end of February 2100. This is when the Gregorian calendar, instituted in 1582, will require a minor correction to be made in order to program the indicators for the next 100 years through until 2200. Having a power reserve of 30 days means that the 601-part calibre 2051 calls for little in the way of attention. Should the timepiece stop when its proud owner is away for an extended period, the separate correctors make it easy to correct the day, month and date subsequently. The dial is further enhanced by a delightful three-dimensional moon phase display, on which the hand-painted rotating ball at the “12” bears a remarkable likeness to the mystical moon. Great importance is placed on the accuracy of the moon phase as well as on its appearance, however: This indication will not deviate a full day from the astronomical norm for another 122 years. A blue funnel-shaped sky disc provides a worthy background to the moon phase display, embellished as it is with ten small 0.1-carat diamonds to symbolise stars shining in the sky. Six further anniversary diamonds act as additional twinkling indices for the even-numbered hours.
The advancement of the Opus Perpetual’s eponymous calendar, which is made up of 130 components, is truly a masterstroke of engineering. For energy reasons, advancement takes several hours for other movements, with the hands moving from one position to the next very slowly. This is not the case with the sensational precision pendulum clock from Erwin Sattler, however, thanks to its special design. Its movement features a melodious strike train too, which announces the full and half hours with sound. A separate weight even guarantees propulsion over 30 days. Its mass generates enough force to advance the calendar mechanism to the next day in just 12 seconds − i. e. during the 12 strikes at midnight − and also to the next month. The precision of the movement therefore remains completely unaffected. The strike train in the Opus Perpetual offers yet another special feature. In contrast to simple designs that have a countwheel, the elaborate rack and snail mechanism guarantees that the clock will strike the correct hour even if the hands are moved forwards or backwards without waiting for the sequence of chimes to finish. A tubular gong provides pleasant sound quality. Should the clock’s owner only wish to enjoy its soft ticking, however, the strike train can be suppressed with a simple hand movement.
The beating heart of the precision pendulum clock is the calibre 2051, which is made in-house. Comprising 601 components in total, it is one of the most complex movements that clock manufacturer Erwin Sattler has ever produced. It goes without saying all parts are made of the very finest materials available, finished with care and lovingly put together. The wheels rotate between solid brass plates that are 4 mm thick. An electroplated nickel coating provides protection against oxidation. To reduce the masses in motion, the 24 gold-plated gear wheels are spoked as much as is technically feasible and sit upon solid, fully hardened steel arbors with precisely milled pinions. 48 stainless steel precision ball bearings and four chatoned jewel bearings ensure almost frictionless rotation. These elaborate measures serve to achieve functional perfection, reducing energy loss to an absolute minimum. The George Graham lever escapement has two agate pallets. A seconds pendulum with a 12 mm-thick invar rod, a steel-nickel alloy with minimal thermal expansion coefficients and a steel element to compensate for unavoidable fluctuations in temperature act as an oscillator.
The accuracy of the pendulum clock can be affected by changes in the air pressure too, which is why the Opus Perpetual has a bilateral barometric compensator on the pendulum rod: When the air pressure rises, the aneroid capsules are pushed together. This causes the weights on the capsules to move downwards, shifting the entire pendulum’s centre of gravity accordingly. Similarly, the two weights are raised when the air pressure falls. The two tungsten weights (weighing 6,800 g each) for the gravity drive are attached to ball-bearing rope pulleys. These sophisticated structures have a positive effect on accuracy, and providing the Opus Perpetual is regulated carefully, its monthly drift is as low as one or two seconds.
The Opus Perpetual also takes its exceptional aesthetics from its attractive case, which protects and houses the technologically impressive movement. Made from massive aluminium, the 152 cm-high, 39 cm-wide, 22 cm-deep case will draw the eye to any wall it is placed against. The look is completed by a lively olive root wood cassette, while the pane of anti-reflective mineral glass provides a tantalising glimpse inside. On request, the cassette can also be made in a different wood or in carbon. To celebrate its anniversary fittingly, the Erwin Sattler manufacture is making only 60 Opus Perpetual timepieces. The number of each piece is indicated by a plaque at the “6” on the skeletonised dial.
HOW DOES THE PERPETUAL CALENDAR IN THE CALIBRE 2051 WORK?
In the calibre 2051 by the Erwin Sattler manufacture, the cen-tral hour wheel drives the calendar mechanism. This turns on its own axis once every 12 hours, making it necessary to halve the rotational speed just once every 24 hours in order to advance the indicators correctly. To account for the pecu-liarities of the Julian calendar, in which months have different lengths and there is a leap year after three normal years of 365 days, a component known as a month cam is required.
Ridges and indentations signal how long the relevant month is to the main switching lever, which “feels” the edge of this specially shaped component. Since February has 28 days three times and then 29, a four-year wheel is needed too, which rotates 90 degrees a year in a cut-out on the month cam. At the end of the month, the main switching lever works together with a toothed snail disc. In months that have 31 days, which are marked by ridges on the month cam, the pawl of the main switching lever moves completely normally over the tooth, advancing the date and month indicators by one posi-tion as it does so. If a month has less than 31 days, however, the rear end of the main switching lever moves deeper into the month cam accordingly. This makes it go back further, so the pawl moves over the aforementioned tooth after 30, 29 or 28 days instead, thereby advancing the calendar to the first day of the following month. The day and month displays remain unaffected by this. The calendar mechanism moves one position on every day.
Professional installation by one of the manufacturers master clock makers is included in the purchase price within the United States and Canada. Inquire about our international installation rates.
All Erwin Sattler models are manufactured to order by hand. Please expect a 4-6 weeks delivery time frame.