Page 21 - LEGO MINDSTORMS - Robotics Invention System-2 Projects

Robot 1 • The Bug

Bumper Step 6

The rubber band pulls
the feelers against the
mechanical stop.

Bricks & Chips…

Rubber Band Sizes
The rubber band must be small enough to hold the feelers against
the stop, otherwise the bumper might indicate a collision when
none has occurred. If the band is too small, the bumper will be
slow to respond to collisions. The white belt and the small black
rubber band are both just the right size.

Bumper Step 7

The ribbed hose
extends the reach of the
feelers. It also acts like a spring,
absorbing most of the shock from
collisions.

Bricks & Chips…
Problems with Hose Sizes
The ribbed hose does not appear to be made to the same exacting toler-
ances as other LEGO parts. Some fit very tightly when slid over an axle,
while others are loose. If you have a problem with the hose slipping off,
remove the hose and gently pinch the end (but not so hard as to kink it).
This will deform the hose a little and make the fit a bit tighter.

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