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One of the best animations I have seen. Although I am still left with one question: how come the impulse pallet misses the escapement tooth in one direction, but engages it in the other? This has puzzled me ever since I saw a cutout version at a watch exhibition at the Imperial Science Museum in London.

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The animation in the article is too fast to see what's happening. The impulse pallet misses the stationary escapement tooth in both directions. During the short period the escapement wheel is moving, it pushes the pallet, giving the balance wheel a push.

Here's a working model in slow motion.[1] Notice the escapement wheel pushing the impulse pallet. Not the other way round.

[1] https://youtu.be/JSNDjuKPdng?t=102

If you look at the second animation closely you can see that there's a piece of spring steel one one side. In the animation it's only a 1-or-so pixel line. But that piece of spring steel open in one direction, but in the other direction it's stiff enough it will push the arm instead of bending.

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