Deadbeat Escapement Problem

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Deadbeat Escapement Problem

Post by PRundle »

I'm trying to relate a simulatiion to a real life situation but am having problems.

Whichever parameter I change (drop lock angles etc) the pendulum swing stays at +/- 1.5 deg.

When I simulate the rotational angle changes from about -4.4 to about 1.4, again not changing with a change of parameters. This suggests that the total swing is 5.8 deg or +/- 2.9 deg?

I am trying to simulate a design where the escape wheel is 47.62mm diameter, and the actual pendulum swing is +/- 1.6 deg at most.

I think  must be missing something? Any suggestions?


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Re: Deadbeat Escapement Problem

Post by ArtF »

Hi Pat:

  Its been awhile since Ive dealt with swing mechanics so I took a look at the code
to make sure of how that works.

  The formula for the swing of a pendulum ( theoretical swing, actual will depend on
the setup of its beat and weight..) is, in a recoil escapement...

((PI / Teeth) - (DropAngle + TipAngle)) /2;   

  However, in looking at the code I see the in the walker escapement, the formula used for the
pendulum sing in simulation is simply

(PI / Teeth) / 2;

    The recoil was developed after the graham as I recall, and Im wondering if whatever horological
tables I used simplified this equation of the swing. Im thinking the dropand tip angles should
have been included in this escapement as well. Normally you have only the tooth count, the lock
and drop to set swing with, so with the walkers simplified display of angle its hard to be as exact as you wish.

  I will fix this in future once I convince myself this is an error and not a difference between the two.

  hmm, as I investigate it becomes clear the walker seems wrong. I tested a modification and the angle seems
more correct in this version. I will have to give it some thought before making it an official fix.

Please send me a note to me at support and I will send you a temporary version
that corrects this display in walker, the drop and tip relief now adjust the calculated swing


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