Equation clock

NigelW

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Jan 2, 2015
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If and when I ever get through my large backlog of clock restoration projects at my less than snail-like pace, my ambition is to make an equation clock. A few years ago I worked out the gearing for a differential using planet wheels which move to and fro through a relatively limited arc driven by the equation cam on the year wheel in order to have a solar minute hand on the same control arbour and the mean minute hand.

I have pored over many grainy photos of equation movements to try to work out what train counts other makers have used but with little success. However I have just come across a picture of a French clock from c. 1800 which I may be able to decipher. It have the same arrangement as my design but the wheels have more teeth. It is also month going, which is better for this kind of clock, and for some reason has a remontoire which seems unnecessary in a weight driven clock of this duration.

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DeanT

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Mar 22, 2009
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I think I know someone with the details and has made a similar clock….let me check and I’ll revert once I remember where

Do you have a copy of Henry King's book Geared to the Stars...very expensive but keep an eye out.

And the book by Rees
 
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Jevan

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Jul 31, 2014
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This drawing is of an English longcase similar to the George Graham clock in the British Museum which is dated between 1740/50.
Although the equation work wheel-count information is not shown I do have that information if of interest to your project.

See also: The Longcase Clock (Tom Robinson, 1981) pp. 184 - 191

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NigelW

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Thanks Jevan.

That Graham clock is one I have studied from the photos on the British Museum website. It is beautiful but deems more complicated than it needs to be. I would be most interested in the wheel counts.

Nigel
 

NigelW

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Jan 2, 2015
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I think I know someone with the details and has made a similar clock….let me check and I’ll revert once I remember where

Do you have a copy of Henry King's book Geared to the Stars...very expensive but keep an eye out.

And the book by Rees
Thanks Dean

I have "Geared to the stars" - I found a (relatively) cheap copy and asked my wife to give it to me as a birthday present. Not familiar with the Rees book.

Nigel
 

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