Elenco Snap Circuits Motion - Manual (Page 36)

Use the preceding circuit, but replace the 1.75” and 2.55”
gears with the 1.0” (smallest) and 3.3“ (largest) gears. Try
it both ways:
Part A: With the smallest gear on the geared motor and
the largest gear on the pivot stand, the merry-go-round (or
disc) should spin very slow. Compare the size difference
between the gears to how much faster one is spinning.
Part B: With the largest gear on the geared motor and the
smallest gear on the pivot stand, the merry-go-round (or
disc) should spin very fast.
Build the circuit shown. Mount the 1.75” gear on the geared motor (GM), mount
the 2.55” gear on the “+” shaped bar, place the “+” bar into the pivot stand,
and then align the position of the 2.55” gear on the “+” shaft so the teeth of
both gears mesh. Either insert some of the cardboard figures into the 3 slots
on the edge of the merry-go-round base, or install one of the colored discs into
the base. Mount the merry-go-round base onto the top of the “+” shaped bar.
Turn on the slide switch (S1), and notice how fast the merry-go-round (or disc)
is spinning. If the gear slides down the “+” bar during use then add a rubber
ring to keep it in place.
Part B: Swap the positions of the 1.75” and 2.55” gears, so that the larger gear
is on the geared motor and the smaller one is on the “+” shaped bar. Notice
how much faster the merry-go-round is spinning now. Compare the size
difference between the gears to how much faster one is spinning.
Part C: Remove the pivot stand and mount the merry-go-round base directly
on the geared motor. Compare the speed to how it was when using the gears.
Part D: Try replacing the 3-snap wire with a second battery holder (B1). This
can be done with any of the above gear arrangements. The additional battery
voltage makes things spin faster.
Project 51 Fun with Gears
Gears can be used to make things spin faster or slower. When
one gear has more teeth than another, it will spin slower. Using
gears to reduce rotation speed also increases the turning force,
allowing it to overcome more friction. Using gears also changes
the direction of rotation.
Inside the geared motor (GM) is a motor spinning very fast, but
with little force (much too little to spin the merry-go-round). Several
small gears connect the motor to the white “+” shaped shaft; these
reduce the rotation speed, giving the shaft enough force to spin
the merry-go-round, and also making it easier to control.
Note: You cannot use the
1.0” or 3.3” gears with the
1.75” or 2.55” gears,
because you cannot get
the proper spacing
needed for their teeth to
mesh well enough.
-35-
Project 53
Spin Draw
Use either of the preceding two circuits, with any of the
described gear combinations. Cut a piece of white paper to the
same size as one of our discs, or use the back of our discs.
Put them in the merry-go-round base and spin it.
Take a soft marker and GENTLY touch it on the spinning disc.
Move it around to draw patterns on the disc. Try starting in the
middle and slowly moving your marker outward. Be careful not
to use too much force or you could damage your parts.
If gear slides down “+” shaft during use
then add a rubber ring to keep it in place.
Ledge must be
on bottom side
Project 52 Higher Gear Ratio
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