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Old 24-07-2015, 12:48 PM
Steve_C
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Steve_C is offline
 
Join Date: Jul 2015
Location: Sydney, Australia
Posts: 56
Quote:

Let's say you build a tracker with a 20TPI 1/4" whitworth rod and a 10 inch arm radius, every turn of the nut advances the arm by
206265 ÷ 20 TPI ÷10 inch = 1031 arc sec per turn of the nut. But the sky only moves at 15.04 arc sec per sec. So you need to turn the nut at 1 turn every 68.6 seconds.
Where does the figure of 206265 come from?
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