by Ian Skellern
(c) May 2005
Enter Max Büsser, Harry Winston and the Opus V
Further discussions with Büsser followed in Geneva and both parties' interest in collaboration grew. Büsser wanted to alternate a ‘crazy’ Opus model with a more traditional one. Vianney Halter’s Opus III was as zany and crazy as they come; Christophe Claret’s reversible Opus IV, with tourbillon, cathedral gong minute repeater, date and a huge central moon phase was a traditional model (in what other series of watches but Opus could a watch like that be called traditional?). Büsser was on the look out for someone who could think ‘outside of the box’ and create the Opus V.
By the middle of 2003, Büsser decided URWERK had all the qualities he was looking for. URWERK put three initial proposals to Harry Winston; the first was considered too risky technically to complete in the time frame available (however, elements of the project may see light of day in the future); the second had the time going past on a type of continuous band; the third showed the little cubic satellites and this was the one chosen.
When the satellite proposal was agreed, various configurations were considered. Notice anything special on the case above?
Suggestions and proposals flew back and forth and by the end of the year the final design was agreed. The end result was very much a partnership with Harry Winston contributing essential design elements to the case: including the crown cover and the back of the watch.
The technical drawings take shape.
URWERK and Harry Winston now had just over twelve months in which to turn a technical drawing of something never dreamed of before - let alone constructed- into a functioning and reliable timepiece.
The satellite system The retrograde minute - easy on paper!
The retrograde minute on the other hand proved much more troublesome. Retrograde
mechanisms are traditionally controlled from their center axis; in the case of the Opus V, the center of the retrograde was occupied
by another complication – the satellite system. Baumgartner knew of no other retrograde mechanism that dealt with
another complication in its center and, therefore, had no Model to test
functionality of the satellite system.
Click here for an animation of a standard retrograde function (bottom center symbol). Courtesy of MontresPassion
Baumgartner had already solved the problem months before . . . on paper that is. The minute hand would be attached to a large diameter, precision ball-bearing circling the satellite system and powered by a double star. The problem was that specialist micro- bearing manufacturers told him repeatedly that making a large diameter ball-bearing with such a thin cross-section was impossible. Impossible? The word isn't in Baumgartner's vocabulary.
From a design sense the minute hand is on the left of the hour indications for a number of reasons; technically it makes sense on the left; aesthetically it helps to balance the visual weight of the hour satellites on the right; thirdly, URWERK's research showed a strong preference for time indicators moving in a clockwise direction. Placing the minute hand on the left allowed URWERK to fulfill all three criteria.
The bearing which circles the satellite system. This unfinished prototype has the minute hand attached.
The small double- star inside the bearing transmits power
to the satellite system and to the retrograde minutes.
Eventually Baumgartner found someone who managed to develop the techniques to make the bearing. However, when it was trialled in a prototype, he found that the 12mm (1/2”) traction spring which returns the retrograde - itself a non-traditional solution - was too strong; this caused large variations in torque across the arc of the minute hand and used far too much energy overcoming the spring. The solution was to make a spring with a smaller diameter wire, however, they were already at the limit of the possible with a minisucule cross-section of 0.1mm (100 microns). He experimented with ever decreasing wire diameters until he obtained the characteristics he needed at 0.05mm (50microns), or half what was previously thought to be the bottom limit. Unfortunately, to get those perfect springs meant throwing away 90% of them. Obtaining the traction springs needed for the 100 Opus V watches, necessitated testing each one of a 1000 springs and rejecting nine hundred of them.
Note. To put the diameter of the 50 micron wire of the traction spring in perspective, the average human hair is 70-100 microns.
The 12mm traction spring beside a paper clip Stretched giving an idea of the minuscule diameter.
Three specially shaped springs under the satellite system not only permit the whole system to be turned counter clockwise without damage, they also permit the deliberate playful bounce of the minute hand when it returns to zero.
The back and front of the satellite system. On the left image you can see the three springs in between the hour
cubes. They allow the satellite complication to rotate in reverse and bounce the minute hand on its return to zero.
Many parts have been machined from ARCAP P40 because it is an extremely resistant and stable alloy. ARCAP is a copper nickel alloy that is more stable (and expensive) than brass and does not corrode; brass is usually plated with gold, rhodium or palladium. The special finish, where the parts are micro-blasted and then polished with a fine cashmere brush, rewards a close examination under various light sources: sometimes sparkling like a finely cut stone and sometimes like polished marble. This very distinctive finish make the indicators easier to read (with little reflected glare) and contrasts perfectly with the few highly-polished surfaces. The massive looking minute hand is actually made of ARCAP and has a hollowed out back. While titanium would have been lighter, Baumgartner preferred ARCAP because it was possible to manufacture the minute hand with an extremely sharp point and to use the same diamantée finish as the rest of the polished surfaces. URWERK’s signature fine adjustment screw sits discreetly on the back where the owner can regulate the accuracy +/- 15 seconds per day.
The ARCAP P40 movement baseplate after micro-blastingThe back of the minute hand and its bearing
The ARCAP P40 movement plate before (left) and after microblasting. To simply machine these 100
baseplates, took a team of three nearly three months. That includes programming the CNC machine,
making the necessary cutting tools, producing prototypes and then the 100 pieces for the series.
Putting it all together.
The case starts from a cast block and is then machined to look like the unpolished case on the right
Notice just how complicated the case shape is.
VIDEO ! Click on the image above to see how the CNC machine makes the plate.
In reality it takes over 90 minutes to machine each piece. Warning-file size 7.8mb !
Sébastien preparing the satellites (left) and then assembling the satellite system.
After over nearly two years of work, seven fully functioning and finished production models were finished and presented at BaselWorld 2005.
VIDEO ! Click on the image above for a video of the Opus V in operation. (Warning-file size 4.8mb)
Whether or not the Opus series is permanently laid to rest, and Büsser himself has hinted that the door on Opus is closed but not locked, I very much doubt that he will be satisfied with producing 'ordinary' traditional complications. With or without Opus, I have a feeling that will be seeing some very innovative and interesting watches from Harry Winston Rare Timepieces in the not too distant future.
And that's not all! As if the Opus V was not enough for URWERK
Ian Skellern - May 2005
We welcome comments, suggestions, and corrections to this article.
Copyright may 2005 - Ian Skellern & ThePuristS.com - all rights
Copyright may 2005 - Ian Skellern & ThePuristS.com - all rights
A special thank you to Felix Baumgartner and URWERK for sharing so much of their time and exceptional work and Mr.Maximilian Büsser of Harry Winston Rare Timepieces for his vision and the will to follow it through.
Anthing more than a passing resemblance between my prose and the English language is largely down to the help of MaxH to whom
I owe a large debt of gratitude.