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Unread 07-03-2007, 07:25
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Tim Arnold Tim Arnold is offline
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Re: pic: MARS stretches its 4-bar

Quote:
Originally Posted by Rex114 View Post
Very clever way to get your grabber to go to parallel to the ground on both sides of the robot. Did you also consider using chain with a certain sprocket tooth ratio to get the desired rotation like this four bar system does. I've always wanted to make something like that, it saves having to use another motor for that wrist joint. Great job, any chance we could get some 3d images?


Yep, thats exactly how it works.




Two keyangs in the base, for low CG and linked together for power, run ~8ft of chain up to the linkage and main bar separately. (Our inventor team couldn't get chain to work yet so pretend there is a chain from these up to the sprockets midway up the arm).



The sprockets were made by hand with drill press and skill saw (and a lot of time - spares were later made using a CNC).

More renderings are available in our gallery here.
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