EV3 Grab-and-Lift by Ogaworks
This compact Lego Mindstorms EV3 Grab-and-Lift claw attachment by Ogaworks uses one EV3 Medium Motor to both clamp onto an object and lift it into the air. See the demonstration at the 8:26 portion of this video: <a href="https://youtu.be/nTLB9GWRyuo?t=8m26s" rel="nofollow">youtu.be/nTLB9GWRyuo?t=8m26s</a> . Two Mini Technic Turntables hold the grabber arms and attach to the motor. The black 45590 "Technic, Axle Connector Double Flexible (Rubber)" pieces on the claw arms ( <a href="http://www.bricklink.com/v2/catalog/catalogitem.page?P=45590#T=C" rel="nofollow">www.bricklink.com/v2/catalog/catalogitem.page?P=45590#T=C</a> ) are optional, but help hold the object from slipping.
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