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The LEGO Turning Machine • Masterpiece 3 135

The light sensor for the Light Sensor sub-assembly is mounted on the head of the mech-
anism.This sensor enables the head to simultaneously read and write the same cell. It is
very important that the sensor be situated as close as possible to the Tape sub-assembly
for the reading of the sensor to be accurate—even if the external light conditions vary.
However, in placing the Light Sensor sub-assembly close to the Tape sub-assembly you
should be careful that it does not interfere with the movement of the liftarms moving on
the Tape sub-assembly as it slides by the assembly just below.

Light Sensor Step 0 Light Sensor Step 1

The light sensor is not placed in the
center of the plate. Instead, it is
shifted to one side to allow the
movement of the liftarms.

Light Sensor Step 2