I spent a little bit of time on the wooden orrery today. Click here for the original post and description. Two more sets of Gears are done (Earth and Mars). Earth's gears are one to one. Each time the driving gear turns once, the planet will spin once. Also everything in this orrery is based on Earth so in some sense there is no error in this gearing. For Mars we have the first of the reduction gears. The gear driving Mars is smaller than the gear Mars is on so Mars spins around slower than the gear driving it. The driving gear has 25 teeth and the gear Mars is attached to has 47 teeth. This gives a year length of 47/25*365.2425 =686.66 days. Mars' orbital period is actually 686.98 days. So there is an error of about 1 part in 2200 (about the same as Mercury and about double that of Venus.) The gear stack is starting to look pretty impressive.
Top view of gear stack (Mercury - Earth)
Side view of gear stack (Mercury - Earth)
Top view of gear stack (Mercury - Mars)
Side view of gear stack (Mercury - Mars)
Close ups of gear stack (Mercury - Mars)
Thursday, February 11, 2010
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I spent a little bit of time on the wooden orrery today. Click here for the original post and description . Two more sets of Gears are done...