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Every gear has a job to do
Like all gears, a worm gear is a wheel with teeth. However, unlike
other gears, a worm gear is not turned by another gear. Instead, it is
turned by a worm – a rod with a spiral edge that resembles a screw.
Every time the worm makes one full turn, the worm gear moves ahead
just a tiny distance – the width of one worm gear tooth!
When you turn the worm slowly, the worm gear turns at a much slower
pace.Worm gears are used in things which need to move very slowly, like
a lawn sprinkler, or in very small movements, like tightening a spotlight so
it shines in precisely the right spot.
1. Carefully, or with the help of an adult, start
your Worm Gear model by plugging the
cord into the gray K’NEX Motor.Watch
theWorm and theWorm Gear turn.
Which way do they move? Draw a picture
with arrows to show the direction that
each part turns.
2
a.
Watch the Worm turn.You can see that
it spins very fast! Then, watch the Worm
Gear turn and have a partner help you
count the number of times it turns in 60
seconds. Mark one spot with tape or a
marker so you can easily tell when the
Worm Gear makes a full rotation. Divide
the number of turns by 60.Your answer
will be the number of turns the Worm
Gear makes per second.Write down
your answer.
b.
Next, count and record the number
of teeth on the Worm Gear.
c.
Every time the Worm turns one full turn,
the Worm Gear moves ahead the distance
of only one small tooth. For the Worm
Gear to make one full turn, the Worm has
to turn the same number of times as the
number of teeth on the Worm Gear.That
means the Worm turns fast! To find out
how fast, try this multiplication problem.
Your answer will be the number of turns
the worm makes per second.That’s fast!
1
2
WARNING:
Important note:
Be extremely
careful whenever using electrical devices.
Teachers should monitor student activities at all
times, and should examine devices before use.
Number of turns
per second
X
Number of worm
gear teeth
The Worm and
Worm Gear
STUDENT ACTIVITY SHEET
Summary of Contents for Education Simple Machines Deluxe GEARS
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