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The magic of the mousetrap
Spring
Bail Wire
Speed or distance
1. For more speed - Move the mousetrap closer to the drive axle. Make sure
that the trap is not too close to the drive axle or the wheels will spin.
2. For more distance travelled – Move the mousetrap away from the drive axle.
Drive Axle
Notice the trap close
to the rear axel! This
trap placement will
give the car more
speed.
Notice the trap far
from the rear axel!
This trap placement
will give the car more
distance.
Ideas for Increasing Distance
Increase Axle-to-Wheel Ratio
1. Use a larger drive wheel. The larger your drive-wheel the
greater the distance your mousetrap car will travel per turn of
the wheel.
2. Use a smaller drive axle. The larger the ratio of drive
wheel(s)-to-axles diameter, the farther you mousetrap car will
go for each turn of the wheel and the greater the pulling
distance will be.
Ideas for Increasing Speed
Decrease Axle-to-Wheel Ratio
1. Decrease the axle to wheel ratio by adding tape to the
drive axle or using smaller drive wheels.
2. 2. Use a larger drive axle. The smaller the ratio of drive
wheel(s)-to-axles diameter, the greater the acceleration
that you will experience. Careful, if the ration is too small
your vehicle will spin its wheels rather than accelerate.
String & Lever arm Length
1. The string length should be a bit longer than the distance from the lever arm
to the drive axle. This will allow the loop to release from the hook, preventing
the string from rewinding. Do not permanently attach the string to the drive
axle
Two kinds of Friction
• Static friction — the force that
prevents motion
from occurring.
• Kinetic friction — the force
that impedes a motion.
Wheels
• If the hole of your wheels is bigger
than the 1/8th inch axles you need an
adapter. You can use a washer or small
wheel hot glued to your wheel.
Insert the part from the bale in
the top of the effort arm.
A little hot glue holds it in.
How motion is created
Add cable tie to drive axle.
Cable tie on axle
Cable tie trimmed to correct
length
Greater distance can be achieved
1. Construct a light chassis – frame
2. Using a longer length lever arm
3. Have a large axle to large wheel
ratio.
4. Reduce friction
5. Increase traction
What to do.
• Click on the link to
view some long
distance cars.
• http://www.docfizzix.c
om/distance_cars.htm
• You can see lots of
different designs by
looking in Google
images.
• With your partner
prepare design
drawings for your
vehicle. Side view
and top view with
measurement using
pencil. Include a list
of materials to be
used and discuss with
the teacher.