Page 224 - LEGO MINDSTORMS - Robotics Invention System-2 Projects

Robot 8 • The ULK (Useful LEGO Knowledge)

Arm Step 5

The #6 axle acts as a stop to prevent ULK’s arm from
dropping too far when reaching down to pick up
LEGO pieces. The perpendicular axle connector and
half-length pin act as part of a stop that prevents ULK
from raising its arm too high.
Inserting the #6 axle is tricky. Interference between the ridges on the bushings
and the studs on top of the beams prevent you from attaching the bushings after
the axle is in place. Instead, first lay the bushings in approximately the right
position, and hold them in place as you slide the axle through.

Arm Step 6

The yellow double
pin and the #4 axle
are part of a mounting
bracket for the light
sensor. The double pin
doesn’t snap all the way
into the bottom of the 2x6
plates, but the
connection is strong
enough to support the sensor.

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