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Reduction Gearbox

Picture
This was a fun rainy day project this weekend inspired by a small piece in the recent Melbourne Meccano Club magazine. Using three worm gears driving three 24 tooth gear wheels in series achieves a reduction in gearing of 13,824:1. In other words I'd have to turn the lower crank handle 13,824 times to make the upper pointer rotate just once. I quickly decided I needed to fit an electric motor to this.

How It Works : At the bottom level one turn of the crank handle turns the lower worm gear once moving the gear wheel round by one tooth. So 24 turns of the handle gives one rotation of the gear wheel.
At the second level its taken 24 turns of the crank to turn the worm gear once, moving its gear wheel round by just one tooth. To fully rotate the second level's gear wheel takes 24 x 24 turns of the crank.
So up on the third level after 24 x 24 turns of the crank the third gear wheel has been moved by just one tooth. It will take 24 x 24 x 24 = 13,824 turns of the crank to rotate that gear wheel fully, indicated by the pointer on the front.

Built : August 2015
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