Motorized Fan
Playing around with the large and small K'nex gears, we built up a sturdy
gearbox that used two pairs of blue and red gears to twice raise the rotational
speed of a hand crank. Since the K'nex blue gear has 14 teeth and the red gear
34, each such pair of gears increases the rate of rotation by a factor of about
2.4. For two pairs of gears, the increase is nearly 6X. Additional increases
are theoretically possible by adding more gear pairs, but the torque required to
get the whole gearbox moving increases dramatically. Starting out as a
hand-cranked model, the K'nex Motor Pack (shown) was later used in the fan to
provide a blur of motion for four fan blades. These blades are a colorful
variation on old-fashioned windmill vanes, and are constructed from yellow rods
and orange connectors. Another feature of the K'nex fan is the orientation of
the dark-grey axle spacers in a spiral pattern, which produces an interesting
visual effect when the axle is in motion.
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redistribution is expressly prohibited without the prior written consent of
Balmoral Software.