Building Robots With Lego Mindstorms

456 Chapter 23 • Drawing and Writing

Analyzing the Tape Writer in detail, you can see that it’s made of a body and

three subsystems, all of them with one degree of a freedom.

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The body provides the main structures and hosts the paper transport

system.

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There’s a movable carriage over the body, which transports the pen in a

direction perpendicular to the tape.

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Over the carriage, the pen assembly moves up and down.

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At the bottom of the body, there’s the writing surface, a smooth surface

that presses the paper against the wheels.

Looking inside the main body, you catch a glimpse of the transport wheels

and the pen assembly (Figure 23.11).

The wheels are ...