Elenco Snap Circuits Motion - Manual (Page 38)

Draw your own patterns on paper
or cardboard, then cut them to the
same size as our discs. You can
also draw patterns on the backs of
our discs. Put them in the merry-
go-round base and repeat the
preceding project. Have a contest
with your friends to see who can
make the most interesting hypnotic
or strobe effects! You can also find
lots of fun patterns and visual
illusions by doing a search on the
internet.
Project 55
Make Your
Own Patterns
Build the circuit shown. Mount the 0.9” pulley on the geared motor (GM), mount the 1.3” pulley on the “+”
shaped bar, place the “+” bar into the pivot stand, and then align the position of the 1.3” pulley on the “+”
shaft so it is the same height as the 0.9” pulley. Place the rubber band around both pulleys. 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
pulley slides down the “+” bar during use then add a rubber ring to keep it in place.
Part B: Swap the positions of the 0.9” and 1.3” pulleys, so that the larger pulley 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 pulleys 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 pulleys.
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.
Part E: Replace the rubber band with one from your home, and change the location of the pivot stand on
the base grid so there is tension in your rubber band. Don’t make the band too tight, because then the
snaps on the pivot stand may not be able to hold it in place. Turn on the circuit and see how well it works.
Note: If the pivot stand comes off the base grid due to the tension of the rubber band, see the next
project for help.
Project 56 Fun with Pulleys
Pulleys can be used to make things spin faster or
slower. When one pulley is larger than another, it will
spin slower. Using pulleys to reduce rotation speed
also increases the turning force, allowing it to
overcome more friction.
Pulley transfer power across small distances, because
the pulleys are separated by a small gap, such as that
between the geared motor and pivot stand here.
It is important to have the proper tension in the rubber
band (or other material) attached between the pulleys.
If there is too much tension, energy is lost and there is
too much strain on the shafts and band, so these soon
break. If there too little tension in the band, the band
may start slipping or fall off. The bands used with pulleys
are typically made of durable materials like nylon.
-37-
If pulley slides down “+” shaft during use
then add a rubber ring to keep it in place.
Ledge must be on bottom side
SCM-165_Manual_061114.qxp_Layout 1 7/7/14 11:29 AM Page 38