MB&F “Kelys& Chirp” by Reuge and Nicolas Court

Kelys& Chirp is a result of collaboration of Swiss horological lab MB&F with two masters: Reuge, manufacture of premium mechanical music boxes and automaton specialist Nicolas Court.

Kelys& Chirp is a mechanical turtle automata equipped with a singing bird mechanism. Kelys(from the Greek chelone or chelys for tortoise) moves in a realistic tortoise-like gait with his head moving slowly side-to-side, his movements all in synchronicity with Chirp as springing from her nest and pirouetting, her beak opening and closing, wings flapping, and tail wagging, all in time to the melodic bird song.

Turtles have long represented wisdom in many cultures because of their long life spans (up to 190 years). While Kelys is certainly wise enough (an integrated mechanical sensor ensures that he doesn’t walk off table or desk tops), it’s his playful streak that complements Chirp’s musical exuberance.

Turtles move with a very particular push/pull gait; thanks to unconventional gearing and cams, Kelys moves in a very similar fashion. You can also enjoy a concert by Chirp without Kelys moving by pushing his tail up; with his tail down he walks while Chirp sings.

Chirp’s birdsong sounds amazing, both due to the accuracy of the song and for the fact that such a relatively loud sound emits from such a small object. This is thanks to a 230-year-old invention, generally credited to Pierre Jaquet-Droz (1721–1790), who came up with the idea of the modern Singing Bird complication. By 1785, Droz had both miniaturized the mechanically-controlled bird and developed a compact movement: his secret was in recreating a realistic birdsong using just one bellow of variable pitch rather than multiple single-pitch bellows. The quality of the bird’s song and how well it carries always astonishes the first time it is heard.

Kelys& Chirp may look relatively simple compared to a complicated watch, but its 480 components indicate the complexity within. This is where Nicolas Court and his team worked their magic: working around the Singing Bird, which is a complete movement itself, they faced significant challenges when developing the turtle automaton mechanism. These included moving the relatively heavy (1.4 kg) turtle with the little power available from the small mainspring of the Singing Bird movement, while ensuring that the turtle moved realistically. The first was solved by finding the optimal low ratio gearing, the latter by the use of elliptical gearing in the power train, along with cams dictating the movement of the legs.

Court and his team added a friction clutch security system, which detects surface edges and immediately stops the turtle moving forward over the abyss… They also reintroduced a Reuge security system for the bird movement: if Chirp or her cover accidently pushed down while she is singing, she stops and instantly retreats to her nest.

The scales on Kelys’ shell are individually hand made from high quality leather in 4 different colours, creating a warmer and more natural feel than bare metal.

Kelys& Chirp is available in 4 limited editions of 18pieces each in blue, green, yellow or ochre.

Technical details
The tortoise walks, the bird opens from back, moves and sings.
For 10-12 seconds, the bird flaps its wings, moves its tail, opens its beak in time to the bird song, then as if magically disappears.
The tortoise moves its legs in a realistically intermittent gait, its head moves.
Average tortoise speed: 0.03 m/s (0.06 mph).

Generally rhodium plated brass, stainless steel and 18K white gold for the bird.
Tortoise scales: handmade leathering with coloured calfskin.

Number of components: 480
100% hand assembled

Chirp the singing bird
Materials: 18K polished white gold, eyes in sapphire
Number of components (bird alone): 30
Number of components (bellows): 90
Mainspring: twin-cam spring barrel
Power reserve: 3 cycles of turtle walking and bird singing
Bellows: double bellows system (bi-directional air pushing)
Security mechanism: if the bird or cover are pushed down while the bird is singing, the bird automatically retreats

Kelys the automaton tortoise
Material: grained, satin and polish finishing, rhodium-plated brass, eyes in black onyx gems
Shell: 12 leather scales with individual polished edges
Mechanism for turtle automaton is driven by the Singing Bird movement
Number of components: 100, all rhodium or satin finished
Gear train: elliptical gearing with max/min 1.3/0.8 ratio enables the turtle to advance with a realistically non-regular gait.
Table/desk edge detector: turtle automatically stops when reaching the edge of the surface.
Tail switch: world first tail indication; with the turtle’s tail up it rests in place while the bird sings; with the turtle’s tail down it walks and the bird sings.
Security friction clutch
Circular stainless steel winding key located on tortoise’s belly.

Dimensions and weight:
Weight: approx.1.4 kg
Dimensions: 24 cm (length) x 16 cm (width) x 8 cm (height without bird open)

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