Page 233 - LEGO MINDSTORMS - Robotics Invention System-2 Projects

Robot 8 • The ULK (Useful LEGO Knowledge)

Arm Assembly Step 2

Add the Lifter sub-
assembly. The lifter
raises ULK’s arm
when the motor
rotates in the counter-
clockwise direction. The
fingers (3x3 liftarms) push
against the bottom of the neck,
returning the arm to the upright
position. Spinning the motor
clockwise causes the lifter to
rotate out of the way.

Arm Assembly Step 3

In this step we will add
the Arm sub-assembly built
previously. Turning the
motor in the clockwise
direction causes the fingers to
close. Gripping something in
the fingers prevents gears in the
arm from turning further. This
generates a large amount of
torque on the arm shaft,
causing the arm to rise.

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