Urwerk is one of the uber cool watchmakers which we always keep an eye out. The dynamic team of Felix Baumgartner and Martin Frei are full of interesting ideas. In 2014, they introduced a world first of a watch which is purely mechanical, and yet sports an electronic monitoring device which allows the owner to check the beat rate of the watch without a Witschi machine. This was the Urwerk EMC. Today, they updated their EMC with the TimeHunter X-Ray. A revolution? Well, read on to find out.
The original Urwerk EMC (read our review here), the unique concept combines a precision mechanical movement with an electronic module that monitors its rate. By simply pressing a button the owner can measure the beat rate to see whether the watch is running fast or slow and the amplitude of its balance. And with a simple user adjustment, ensure it is running at optimal timekeeping.
“We have perfected one of the most reliable way of regulating a 100% mechanical watch by making mechanics intelligent,” explains watchmaker Felix Baumgartner, co-founder of URWERK.
Urwerk TimeHunter X-Ray
On the dial side, the Urwerk TimeHunter X-Ray receives a total redesign.
However, the redesign is not a major revamp which require modifications to the movement, the Urwerk manufactured caliber Urwerk UR-EMC. All the pivot positions of the indicators remain unchanged. More credit to Urwerk co-founder Martin for pulling off the redesign. The new watch looks totally unlike the old. Gone are the sub-dial apertures on the case, replaced by a full, more conventional dial with the hour and minute dial on regular hands on a regular dial. But that is where convention ends. The dial is skeletonised.
We hesitate that with the skeletonisation, the visual impact is mildly reminiscent a Richard Mille. The combination of black, white and red graphics on a matt black case does suggest those overtures. But this is unfair as it takes credit away from Martin. So we won’t. Martin’s design and creative genius resulted in a case and dial which is based on conventional concepts, but yet utterly avant garde.
The TimeHunter X-Ray is easy to read with a central dial for black hours and minutes hands coated with white SuperLuminova. A rotating disc showing the seconds at 1 o’clock is balanced by the power-reserve indicator at 7 o’clock. The EMC TimeHunter’s performance indicator showing its rate (± 15 seconds a day) and balance amplitude on demand are at 10 o’clock.
What has not changed?
The movement remains the Urwerk UR-EMC, designed and manufactured in-house in Zurich. This is essentially the same movement as the one found in the original EMC, and the variant known as Urwerk Pistol.
The movement can be seen through the sapphire crystal. Also on the back is the rate-adjustment screw, one of the nerve centres of this watch.
For Martin Frei, co-founder and artistic director of URWERK “the back of the watch reveals two opposing worlds sharing the same case: electronic circuits and the finest mechanical movement. They invite you to find out more — specifically how this unusual timepiece works. The same goes for the face of the watch, for the TimeHunter X-Ray as its name says it, hides nothing. The mechanism, wheel-train, electronic circuits, indeed all the secret operations of the watch are displayed for its owner.”
The key features of the back of the EMC TimeHunter are the adjustment screw and the push-button at the bottom of the dial between the lugs that releases the winding crown. The parts of the movement under the red covers houses the electronic measurement module.
The optical sensors measuring the oscillations is under the red cover over the balance. The sensors are linked by a tiny cable to the electronic components at the top of the photograph above. The circuit board can be seen behind the red lattice cover. Next to the integrated circuit board can be seen the stacked twin barrels.
The UR-EMC movement has the following features:
– Its balance wheel is made of ARCAP, an alloy chosen by Urwerk for its non-magnetic and anti-corrosive qualities. Its unusual shape has been scientifically calculated to be aerodynamic and minimise the effects of air friction and to achieve an optimal amplitude.
– Its twin mainsprings are housed in two superimposed barrels to ensure a constant power supply and a power reserve of 80 hours.
– Its exterior adjustment screw, connected to the fast/slow index on the balance, enables the rate to be adjusted by changing the effective length of the balance spring.
How does it work?
The energy for the electronic rating module is generated by turning a crank. This crank drives a generator made by a Swiss company Maxon. Maxon developed the motors for the NASA Mars expedition.
The energy is stored in a capacitor, and when the button is pressed, the indicator hand first points to one of two symbols: δ (the rate is being measured) or P (insufficient energy). If the measurement is possible the hand then first points to the rate — ± 15 seconds a day — and then, after a short pause, the amplitude of the balance. In addition, a light emitting diode shows green if the watch is performing correctly and red if the rate is outside acceptable tolerances.
The eye of the monitor is an optical sensor which sits on top of the balance wheel.
This sensor measures the number of times each vibration (semi-oscillation) of the 28,800 v/h (4Hz) balance for three seconds. The sensor consists of a light source and a receiver on either side of the balance wheel. Pressing a button on the left of the watch case activates the measurement.
The measurement is then sent to the circuit board which makes the calculations. The reference to which the measurements are compared to is a quartz resonator running at 16 MHz.
As the mechanical balance runs at a frequency of 4 Hz, a very precise evaluation can be made. This calculation is made by a smart electronic chip housed in the circuit board. This chip calculates the difference (δ) between the rate of the balance and that of the reference resonator. Each microsecond of difference corresponds to a gain or loss of a second a day in the rate of the movement. Thus a variation of 0.0000014 seconds in each vibration translates into a gain or loss of one second a day.
The optical sensor also measures the amplitude of the balance wheel.
What is amplitude and how is it measured by the EMC TimeHunter?
The amplitude is an important measure of the health of a watch and is shown in degrees of arc the swing of the oscillating balance wheel. In theory, each oscillation must be isochronous. What this means is that each swing must be exactly the same duration as the next, irrespective of amplitude of the swing. Typically for a wrist watch, a healthy movement will show an amplitude of between 240° and 310°. When the amplitude is too small, the oscillation will take a shorter time to complete, resulting in the watch running fast. And vice versa. Amplitudes higher than 310° can also cause the balance to bank, meaning the lever hits the banking pins, and the balance loses isochronism. Low amplitudes is also an indicator that the balance staff is insufficiently lubricated, and in need of servicing.
We await to get our hands on with the new Urwerk TimeHunter X-Ray, and will report back our analysis on the watch, how it feels, how it operates and the final details on finish.
Until then, we offer our view that the TimeHunter X-Ray is a rather interesting timepiece, although this landmark was crested by Urwerk in 2013 with the original EMC.
What makes this interesting is that now we have the ability to marry the mechanical heart of a watch to an electronic brain to keep it operating at optimum conditions. This is perhaps the advent of the mechanical watch enhanced by electronic functions that provide a diagnosis of its timekeeping performance. Such a watch gives its owner the active role of getting the best performance from his timepiece.
Specifications Urwerk TimeHunter X-Ray – edition limitée 15 pieces.
Price: CHF 125,000 before taxes.
Material: Grade 5 titanium and steel with black PVD treatment
Dimensions: Width 43 mm, length 51 mm, height 15.8 mm
Glass: Sapphire crystal
Water resistance: Pressure tested to 30 m/3ATM
Finish: Brushed and shot peened
Calibre: Calibre UR-EMC designed and manufactured by URWERK
Escapement: Swiss lever
Balance wheel: ARCAP P40; linear balance with an optical reader
Frequency: 28,800 v/h (4 Hz)
Balance spring: Flat
Energy source: Stacked double mainspring barrels coupled in series
Power reserve: 80 hours
Winding: Manually wound
Finish: Openworked baseplate, Geneva stripes, snailing, sand blasting,
Chamfered screw heads
Maxon® hand-cranked generator to charge a capacitor
Optical sensor governed by an integrated circuit;
16,000,000 Hz reference resonator
Hours, minutes, seconds, rate indicator δ, amplitude, power reserve,
Index adjustment screw