Experiment ZR012 by C3H5N3O9

Whenever geniuses of Swiss watch making industry meet, we always witnessed the births of new concepts, new brands and collaborations.

C3H5N3O9 is an experimental platform was born when Felix Baumgartner, Maximilian Büsser, Martin Frei and Serge Kriknoff joined together to experiment with concepts, ideas and creations without the inherent limitations of a luxury brand.

C3H5N3O9 is both the molecular formula for nitroglycerine and a horological experiment. Many of the most reactive (and most exciting) chemical reactions derive from combining seemingly innocuous ingredients.

Urwerk founders Felix Baumgartner and Martin Frei had a concept featuring Wankel engine inspired indications that they had not yet developed, and they suggested their constructor Cyrano Devanthey could develop and produce a movement based on that. MB&F partners Maximilian Büsser and Serge Kriknoff teamed up with independent watch designer Eric Giroud to design and produce the case.

C3H5N3O9 Experiment ZR012 watch

Experiment ZR012 is the first ever timepiece by C3H5N3O9. This world premier model features Wankel engine inspired hour and minute indications in an asymmetrical zirconium case with articulated and compound lugs.

C3H5N3O9 Experiment ZR012 watch

At first glance the time appears to be indicated by centrally rotating triangular rotors; however, the triangles are actually Reuleaux polygons; they rotate eccentrically rather than centrally and track complex epitrochroid curves rather than circles. The system was inspired by the Wankel engine, which features orbital Reuleaux polygon rotors rather than the reciprocating pistons that power the majority of our cars and machines today.

C3H5N3O9 Experiment ZR012 watch

This timepiece will be costing approximately 110,000 Swiss francs (33, 000 Swiss francs for the confirmation of the order) and only available directly from Switzerland. Interested buyer can contact through the contact form of the website.

There will only be two series of 12 Experiments featuring the Wankel complication: ZR012 12 pieces in Zirconium (in 2012) and RG012 12 pieces in red gold (in 2013).

C3H5N3O9 watch movement

Indications: Experiment ZRO12 indicates hours and minutes with two Wankel engine inspired eccentric rotating Reuleaux polygons (triangular-shaped rotors). Hours are indicated by the lower rotor along the front of the ‘dial’, while minutes are indicated by the smaller upper rotor.

Epitrochoid curves: Time is by the tips of the Reuleaux polygon rotors tracing epitrochoid curves. To create the complex shape of the hour and minute epitchroid curves with the high precision required, 180 separate points were plotted. There is tolerance of just o.2omm between the triangular rotors – the special shape is actually called a Reuleaux polygon – and the hour and minute marked epitrochroids surrounding them.

Complication: The Reuleaux polygon (triangular-shaped) rotors are eccentric, i.e. not mounted directly to the central ‘crankshaft’ and they demand considerable time, skill and patience to set up correctly in assembly process. To ensure extremely high precision adjustment the fixed wheels can be rotated slightly (then re-fixed) to allow fine adjustment and synchronised precision between the hour and minute indicators.

C3H5N3O9 Experiment ZR012 watch

Case: The case and lugs of Experiment ZR012 are made from zirconium, which is derived from the mineral zircon. Visually zirconium is similar to titanium and is highly resistant to corrosion.

The case dimensions are 55mm x 44mm (excluding lugs). The articulated front lug and compound rear lug wrap ergonomically around the wrist and ensure a high level of comfort.

C3H5N3O9 Experiment ZR012 watch case-back

Power reserve indicator: Turning Experiment ZR012 over reveals the power reserve indicator. The movement has autonomy of 39 hours and is wound by a large screw down crown.

Wankel engine

In 1919, a 17-year-old German boy called Felix Wankel dreamt of a new type of engine. Despite no formal training, Wankel believed that he could design an engine in which the four stages of intake, compression, combustion and exhaust-took place in one rotation, rather than four separate reciprocations of a piston as in a normal engine.

It was an ambitious goal, which others had been unsuccessfully attempting since the 16th century. In 1924 Wankel created a small laboratory to develop his rotary engine and eventually tested the first prototype in 1957, over three decades later.

One of the main reasons development took so long is that Wankel’s orbital engine was based on a convex-triangle rotor rotating inside a epitrochoid combustion chamber. An epitrochoid is a very complex shape traced by a point on a small circle rotating around the perimeter of a larger circle and plotting that shape involves seriously complex mathematics.

x = cos(w1*t) + (R/L)*cos[(w1+w2)*t]

y = sin(w1*t) + (R/L)*sin[(w1+w2)*t]

In standard internal-combustion engines, pistons reciprocate four times for every cycle of power; in the Wankel engine, power is smoothly generated each rotation with fewer moving parts enabling the motor to be lighter, more compact and more reliable than reciprocating engines.

The epicycloid curve has been of special interest to astronomers over the centuries as the shapes are often found in the coronas of stars. Wankel was the first to use an epicyloid in an internal combustion engine. Experiment ZR012 is the first to use an epicyloid in a wristwatch.

Technical details

Model: C3H5N3O9 Experiment ZR012 Watch

Edition
Experiment ZR012 is an edition of 12 pieces in zirconium. Hours and minutes are indicated by two Wankel engine inspired Reuleaux polygon rotors tracing epitrochoid curves.

Case
Dimensions without lugs: 55mm x 44mm
Case and lugs: Zirconium case with titanium lugs
Number of case components: 60
Compound front lug, articulated rear lug
Sapphire crystal with anti-reflective treatment both side
Water resistance: 30m – 100’ – 3atm
Strap and buckle: Brown calf leather strap. Titanium and white gold folding buckle.

Movement
Movement dimensions: 32.65mm x: 41.35mm: 11.55 mm
Number of components: 328
Number of jewels: 42
Manual winding
Power reserve: 39h
Balance frequency: 28’800
Finishing: satin finishing, sandblasted, circular graining on movement, black PVD treated components, black ruthenium treated components
Number of plots to create epitrochoids for hours and minutes: 180
Tolerance between hour and minute indication rotors and inside of epitrochoids: 0.20mm