Vol. 25: The Chinese Windlass
British soldiers, encamped on the outskirts of Beijing after the war, took note of an ingenious device being used to raise and lower drawbridges.
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» MAKE: AMENDS Errata for This Article
Correction for page 171
Volume 26's Make Amends incorrectly corrected the equation values in Volume 25's Remaking History. Aargh! The crank length (a radius) is 6" as originally stated, but the radius of the large barrel is 1.5". The value of the expression is therefore 96, not 48.
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Windlass Calculations
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I found your article fascinating and, when I came to your calculations, puzzling. Why is the first fraction in the purchase not
6/1.5
rather than the 6/3 shown on page 170? The denominator is supposed to be the radius of the large barrel.
Let me know.
Thanks.
Thomas.
Posted by Thomas Kowal on March 09, 2011 at 18:42:16 Pacific Time

Windlass Calculations
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You're right, Thomas. You'll see the correction has been added to this article page:
The crank length (a radius) is 6" as originally stated, but the radius of the large barrel is 1.5". The value of the expression is therefore 96, not 48.
Thank you for pointing that out.Posted by Laura Cochrane on April 21, 2011 at 16:14:56 Pacific Time

Windlass Calculations
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I am planning on making this project. As I have a variety of raw materials (pipe diameters, etc) I wonder if there is any logic to determine the optimum or desireable difference in the drum diameters. Yours was 1/4" but how about a larger difference, say 1/2" or a smaller difference, say 1/8"? Thanks
GTO JerPosted by GTO Jer on November 06, 2011 at 21:29:03 Pacific Time
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