CALIBRE 27

Manufacture C27-M · Le Sentier workshop

A watch that runs with its heart open.

CALIBRE 27 presents the C27-M: a hand-wound manufacture movement shown on an anthracite velvet tray, opened layer by layer under a narrow bench lamp. The barrel, train, escapement, and balance are not rendered as a picture. They are live SVG parts, timed to a 21 600 vph cadence.

Frequency
21 600 vph
Reserve
72 h
Jewels
31
Exploded mechanical movement C27-M A layered SVG watch movement with barrel, gear train, escapement, balance, jewel settings, bridges, and screws. Scroll changes the assembly state and the wheels run at geared ratios. baseplate train bridge barrel · 72 h ratchet center wheel third wheel fourth wheel escape pallet balance · 3 Hz balance bridge 31 jewels screws
Bench light, not showroom light

The manufacture keeps its complications quiet.

At 07:10 the shutters lift over bench C, the loupe trays are opened, and the movement is placed under a single porcelain lamp. CALIBRE 27 builds fewer than 312 C27-M movements a year, each signed by the same pair of hands from initial jewel setting to final rate sheet.

The house style is deliberately restrained: frosted German silver, rose-gold train elements, polished screw countersinks, and a dial cream chapter ring that lets the mechanics carry the drama.

Chief adjuster Mireille Vautrin

Bridge finish 42 minutes per bevel, black-polish at 6 micron

Rate target -1 / +3 s per day after six positions

Assembly room 39% relative humidity, filtered north light

One-minute cage study

The escapement learns to orbit.

The C27-T variation suspends the escapement inside a rotating cage. The whole assembly turns as one unit so gravity never gets the same angle for long; the balance still breathes at 3 hertz while the carriage makes a measured circuit around it.

Rotating tourbillon cage A rose-gold tourbillon carriage rotates around a miniature escape wheel, pallet, and balance assembly.
carriage60 s
display rate18x
balance3 Hz
poise error0.04 g

C27-M technical sheet

Numbers with a watchmaker’s pulse.

Manufacture calibre C27-M
Frequency21 600 vph · 3 Hz · 6 locking impulses per second
Power reserve72 h from a single oversized barrel with slipping bridle
Jewels31 jewels, including 3 screwed gold chatons and capped balance endstones
Diameter31.70 mm
Height5.42 mm
Train math96 → 80 → 64 → 60 → 15 teeth, displayed at exact visual ratios
AdjustmentSix positions, two temperatures, -1 / +3 s per day
FinishingFrosted plate, polished bevels, rose-gold wheels, heat-blued screws

Surface work

Every reflection has a job.

The C27-M is decorated to reveal contact, tension, and depth. The barrel cover is circular-grained so winding marks remain legible. The bridge bevels are bright enough to catch the lamp but narrow enough to avoid jewelry theatrics. The screw heads are blued only after their slots are polished flat.

Frosted plate

A matte rhodium surface softens the anthracite tray and makes each jewel setting glow.

Mirror bevel

Hand-drawn edges interrupt the darkness with precise silver cuts of bench light.

Rose-gold train

Warm alloy wheels separate the going train from the cooler German silver architecture.

2027 atelier allocation

312 movements. No louder than that.

Every C27-M leaves the manufacture with a signed timing card, a hand-drawn layer diagram, and a recording of its first full wind. The watch is delivered on dial cream enamel with a small seconds register that exposes the fourth wheel’s minute-long discipline.

Return to the open movement
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Le Sentier appointments126
Collectors circle72
Movement archive30