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Lume Workshop / Interactive model

When the blade snaps

Start with one elastic part. Then follow energy through the watch. Two experiments with separate, stated assumptions.

LUME WORKSHOP / CONSTANT ESCAPEMENT

When the blade snaps

Start with one elastic part. Then follow energy through the watch. Two experiments with separate, stated assumptions.

Find it in the watch
An original Neo Constant Escapement detail showing the purple frame, fine blade and balance beneath the lower bridge.
Photo: Girard-Perregaux, detail from the original 93510-21-1930-5CX front view.

The blade runs approximately horizontally inside the purple frame. The balance is visible behind the lowest black bridge. Central connections give the production blade a wave-like shape. The simpler beam below makes its change of stability easier to follow.

01 / 05

One blade, two places to rest

The fixed ends impose a small compression. The strip can rest bowed towards either side. The coloured ribbon is an enlarged principle beam, not the complete production silicon assembly.

Drag the drawing to rotate the view.

Blade shape q+1.00
Potential energy0.00
Principle threshold±0.385
Ready to startModel time 0.00

External loading increases and reverses automatically. The physical model still calculates the blade motion.

Potential energy
−1.60+1.6

Shape / q · Relative energy

All values are relative. No µJ or measured microseconds.

What is calculated?

Blade mode is a damped single-coordinate mechanical approximation. The spatial ribbon visualises that coordinate. It is neither a finite-element material model nor scale CAD of the GP09200. Energy-metering mode is a separate teaching state machine. Numbers from the two experiments cannot be interchanged. Six half-oscillations per second is a manufacturer specification. The teaching rhythm here is deliberately slower.

Beam model: U(q) = (q² − 1)² / 4. Motion: q″ + 0.45q′ + q(q² − 1) = F. RK4 integration with steps no larger than 1/240. The separate metering model assumes unit doses and keeps its own energy balance.

An original educational illustration, not a complete simulation of a particular calibre.

Why does the blade snap, and how can a prepared energy dose remain consistent?

What to observe

Start automatic loading, then explore the two stable shapes manually. The final two lessons use a separate metering illustration to trace energy from the drive to the balance.

Model limitations

The blade is a dimensionless single-coordinate elastic model. Energy metering uses a separate assumed state machine, not a geometric replica or measured accuracy simulation of the GP09200.

Understand how it works

Girard-Perregaux Constant Escapement. Waiting for the blade to snap ↗

Find the detailed explanation, technical background and sources in the accompanying article.

More models in the Workshop ↗

Share preview image: Watch photographs: Girard-Perregaux. Editorial composition and principle drawing: Lume. · Image use approved by the site owner.

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