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I have a servo that is fixed and that can move a heavy load approximately one inch. I need the fixed servo to move a light load approximately 4 inches. How can I do this with a set of pulleys? Is it even possible. I don't have access to any sort of gears or timing belts either, just pulleys.

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up vote 3 down vote accepted

Yes it's simply a pulley in reverse - pull on the pulley block and the free end of the rope moves.
It is (or at least was) used in some hydraulic lifts/elevators.

https://en.wikipedia.org/wiki/Pulley ( https://en.wikipedia.org/wiki/Pulley )

Pulling on the rope (red arrow) with a small force for a large distance, moves the load (blue arrow) with 4x the force but only 1/4x the distance.
By symmetry you could pull the blue arrow with a force and move the red arrow 4x as far with a smaller force

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Could you draw a picture or elaborate more? I can't seem to visualize how this would work if the servo is fixed. –  captainandcoke Apr 13 '12 at 0:47
    
What software are you using? Thanks for your help. –  captainandcoke Apr 13 '12 at 4:07
    
@captainandcoke - copied image from wiki - see link –  Martin Beckett Apr 13 '12 at 4:35
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