MB & F, the Horology Creative Lab based in Switzerland presents their new model – HM5 RT, an exceptional Horological Machine packed with lots of surprises. It takes inspiration from every innovative things of 70’s – Quartz watches, Super cars, Rockets, etc..
This mechanical watch model which takes inspiration from the 1970s designs and innovations however features a futuristic case design. Hour and minute displays look straightforward, but they are bi-directional jumping hours with indications inversed, reflected 90° and magnified 20%.
A deep-brush case finish brings out the lush richness of the 5N red gold and the warmth of the precious metal creates a perfect juxtaposition with the cool electric-blue trim around the time display. Grade 5 titanium flanking the lower sides and base of the case both highlights and softens the formal nobility of the red gold.
The generously sized 51.5mm x 49mm case in gold ensures the aesthetic beauty; and the discrete use of ultra-light titanium makes HM5 RT light weight and a very comfortable machine to wear.
HM5 RT is a luxurious limited edition of 66 pieces in 5N red gold and titanium. The wedge-shaped case of On the Road Again pays homage to Amida Digitrend watch and low-slung supercars of 1970s.
The purpose of the louvres on these awe-inspiring cars was to restrict sunlight (and heat) from entering the near horizontal rear window. The functional louvres on HM5 do the opposite in that they open to allow light down onto the Super-LumiNova numbers on the hours and minutes indication disks to charge them. The disks are actually flat on top of the movement (under the louvres), not vertically at the front of the case where they appear to be thanks to some optical magic. Opening and closing the louvres also changes the dial’s light intensity. The louvres are opened and closed by a slide set into the side of the case.
Another distinguishing feature of supercars is large dual exhaust pipes that are usually seen accompanied by a roar of engine noise and smoking rubber. But HM5’s exhausts are not there to expel combustion gases in a throaty roar, but to drain water in case.
HM5 RT’s ergonomically sculptured crown – inset with the MB&F battle-axe motif – takes inspiration from Rockets. To minimise potential damage, the crown winding stem is guided by three radial bearings. It can only be pulled/pushed when perpendicular to the movement.
The actual hour and minute time displays on HM5 RT, i.e. the numbered rotating disks, are relatively simple: overlapping disks (one for hours, one for minutes) are completely covered in Super-LumiNova, which then has large 8mm numerals created by masking all of the lume except for the numbers.
The disks rotate flat on top of the movement and yet we see the time indications vertically in a ‘dashboard’ at the front of the case. To achieve this, MB&F worked with a high-precision optical glass supplier to develop a sapphire crystal reflective prism that bent light from the disks 90° as well as magnify it by 20% to maximise legibility.
The sapphire prism is wedge-shaped with the angles precisely calculated to ensure that light is reflected from the horizontal indications to the vertical rather than refracted (bent). A convex lens at the front provides the magnification. Sapphire crystal is much more difficult to work to optical precision than glass and it took considerable development and meticulous care in production to create crystals that reflected and bent light without the slightest distortion.
Because the time is reflected, the numbers are printed on the disks as mirror images so that they display correctly on the ‘dial’. The glass on the front is not black but dark-tinted so that it is possible to see time arriving and departing and the numbers have an iridescent outline, reminiscent of the original Digitrend and the glowing instruments of a supercar on a high-speed road trip at night. The vertical forward-facing display makes HM5 RT an excellent driver’s watch as there is no need to lift your wrist from the steering wheel to read the display.
The Engine is housed in an inner titanium container for better water resistance. This inner case is similar to the rigid chassis of a car on which the external coachwork/body is attached.
Jean-François Mojon, Vincent Boucard and the team at Chronode developed the HM5 Engine. Jumping hours are bi-directional, enabling the time to be easily set oth forwards and backwards. The two mineral glass disks of the hours and minutes are supported by a flat wide bridge. The disks overlap to maximise their diameter and space for large legible numerals.
The transparent caseback reveals the Engine, with its 22k gold battle-axe shaped ‘mystery’ winding rotor, fast oscillating balance and stunning hand-finished bridges, through a sapphire crystal display back that is set into the water resistant container.
Three-dimensional horological engine developed by Jean-François Mojon and Vincent Boucard of Chronode
Powered by a Sowind gear train
Battle-axe 22k gold ‘mystery’ automatic winding rotor
Power reserve: 42 hours
Balance frequency: 28,800bph/4Hz
Number of components: 224
Number of jewels: 30
Engine housed in water resistant, titanium inner container
Functions / Indications
Minutes and bi-directional jumping hours displayed by reflective sapphire crystal prism with integrated magnifying lens
Slide to open/close louvres on case top
18k red gold and titanium with internal water resistant titanium engine container
Slide button to open/close louvres
Exhaust ports to drain water
Dimensions: 51.5mm x 49mm x 22.5mm
Number of components: 80
Water resistance of engine container: 30m / 90’ / 3atm
Smoked optical grade sapphire crystal with anti-reflective coating and 20% magnification
Sapphire crystal on back with anti-reflective treatment on both faces
Strap & Buckle
Sculptured rubber strap, titanium tang buckle