Pulley motor car is an
electric car using pulleys to transfer the mechanical energy
from the motor to the wheels. MiniScience's Pulley Car
activity introduces students to compound machines and simple
machines including pulley, wheel and axle while
incorporating problem solving, mechanical design and
modeling. In addition, students will experience using hand
tools as they construct their Pulley Motor Car.
Students can explore:
- Propulsion types and drive
- Basic soldering techniques and
- Simple electric circuit
including battery, motor and switch
| Teacher Preparation:
During construction of the
Pulley Motor racer vehicle, students can experiment and
comprehend methods of power transfer, soldering (optional),
wheel alignment and calculating pulley wheel ratios. It is
up to the teacher to make sure this background information
is provided to students in some manner.
Before using the kit please
make sure you have all the items listed below. This kit has
the supplies to build one pulley motor car model. A pulley
motor car is an electric car that uses pulleys and belts for
its transmission system.
- Battery Holder
- AC motor
- Rear Slicks 1 9/16"
diameter x 5/8" wide
- Front Wheels 1 3/8"
- 1/8" dowel for axles
- Traction Bands
- Eyelets or washers
- Eye Screws
- Wood Sheet 5" x 2" x 3/32" (or
larger, so you can cut to any size)
- Axle Guards, Basswood 1/5" x
1/5" x 2" (5mm x 5mm x 5cm) sticks
- Motor Mount (With straps if
- Procedure Sheet
Propulsion systems include
using two AA batteries and a DC motor with a Pulley and
Rubber band drive.
Advanced students are
encouraged to experiment with different size pulleys.
Basic Tools Required
These items may be required to
build the pulley motor vehicle: (You can make
your car model without them as well)
- craft knife, used to cut or
trim soft wood.
- White glue, wood glue or glue
- Soldering Iron, needed if you
need to solder wires.
- Pliers, used to connect and
twist wires together if needed
- rulers, used for measurements
- Pencil, used for marking
During the construction of the
vehicle, the following safety precautions should be observed.
- Wear safety glasses
- Use care with sharp cutting
- Avoid touching the tip of the
glue gun or soldering gun
- Put safety first
Competition between students can be
based on design, drawings, final appearance, distance-traveled,
Races can be held between cars in a
track. Due to the very high speed, design flaws can seriously damage
the vehicle in its first strike to a wall or any hard object.
In addition, teachers could
implement a problem-solving category for advanced or older students.
Teachers would provide students with the pulley car kit then
instruct students to make use of additional materials in the
classroom to construct a customized vehicle. additional items could
include wood scraps, stickers, paint, CD, colored wheels and more.
How elaborate or complex the pulley motor cars are depends on
imagination and resources.
Standard Assembly Steps
Make your pulley motor car model in
3 simple steps.
Construct the basic car chassis with 4 wheels
|Cut a strip of
wood that is 2" (5cm) wide.
Mark the location
of axles by drawing two lines, one on each end of
the car, parallel to the front or back side. Axle
lines must be about 1 inch away from the front or
On the axle lines,
mark two points that are 1/4" (6mm) away from each
side. Insert one eye screw in each of the points.
|Eye screws are
used to hold the axles. Insert the axle and make
sure it is level and it can spin freely. If
necessary, adjust the eye screws.
For the back wheels
cut a space for the pulley before inserting the eye
screws. Without cutting a space for the pulley, one
wheel will stay out about 3/8" more than the other.
|Cut some plastic
tubes or straws and use them as the spacer in both
sides. If you have metal washers, insert them
between the straw pieces and the eye screws.
|Insert the wheels.
Wheels may be inserted while the axle is in
You can also insert
the axle into one wheel and then pass it through the
|At the end your
simple car will look like this. You can use it the
way it is or you can turn it over as shown in the
|In the model shown
here, the gears are built in the rear slicks (rear
wheels). With plain wheels, you had to insert a
pulley or gear in the same axle with one wheel.
If you don't need
to install pulleys or gears, continue with step 2.
|To mount a pulley
or gear next to one wheel, it is a good idea to cut
some space for that on your chassis; otherwise, one
wheel will stand out and your model will not have a
symmetrical shape. The size of this space may vary
depending on the size of your pulley or gear.
(3/8" x 1 1/2" cut
is shown in this example)
|This is how a
pulley or gear may be mounted beside one of the
wheels. The pulley or gear must have a hole matching
the axle diameter and must feet snugly. Some pulleys
and gears require a plastic insert and some drilling
in order to adapt the diameter of the axle you are
using. After mounting, make sure that the wheels can
spin freely. If necessary, mount a metal washer
between the spacer and eye screws.
methods of mounting the axle
|You may not have
eye screws for mounting the axles. This is an
alternate method for mounting wheels and axle.
Insert the axle in
one wheel, slide a washer onto it. Insert a 5 1/2"
straw over it and finally insert another washer and
|Your final wheels
and axle will look like this. Hold the straw and
spin the wheels. Make sure the wheels can spin
freely. If necessary, make some adjustments.
|Cut 4 pieces of 2"
(5cm) long wood strips and glue them about 1/5"
(5mm) apart where you want to mount the axles.
|Insert the axle in
the space between the strips and secure them in
place using some glue. Cover it with a strip of
cardboard or heavy construction paper.
|Note that the glue
will touch the straw, not the axle. This is how the
bottom of your car will look like after covering the
axle holder with a strip of paper.
|Insert the small
gear or pulley onto the motor's shaft. Place the
motor on the self adhesive motor mount and strap it
securely and snugly.
|Place the motor on
the car while the car is on a flat surface. Move it
towards the gears until the gears engage. Mark the
location of the motor. Avoid too much pressure on
the gears because it will increase the friction and
make it difficult for the car to move.
you use pulleys to transmit force, motor must be
mounted away from the pulley so that the rubber belt
is slightly stretched.
Carefully peal off
the protective cover of the adhesive pad. Make sure
you will not remove the adhesive pad itself. Place
the motor where you already marked. Push it down
firmly to stick in place.
Mount the rubber
band belt between the wheel pulley and the motor
the battery holder
|Place the battery
holder on the car, secure it in place with some
glue. Connect the black wire of the battery holder
directly to the motor. Connect the red wire of the
battery holder to the switch, then connect another
small piece of wire from the switch to the motor.
Insert the batteries while the switch is open.
|Test the car while
it is still in your hands. Do the wheels spin? In
what direction? If the wheels are spinning backward,
switch the wires around on the motor. Place the car
on a race track and test it. Does it run on the
|The final pulley
motor car you make may be different based on the
materials you use, the design implementation and
additional decorations you may add.
include wooden or cardboard pieces you can add or
paints you may use.
Alternate Assembly Procedure for
gear driven solar car
The following steps relate to the
construction of the basic pulley motor vehicle. Steps relating to
the completion of the propulsion systems are left to the student's
- Make sure your kit
contains the items listed.
- Locate the grid
planning sheet in the kit.
- Using a pencil and
ruler, design the body of the vehicle and propulsion
Remember, the lighter the vehicle's body, the further it
- Show the drawing to
the teacher when ready.
- Locate the balsawood
sheet from the kit
- Transfer the vehicle
body pattern to the balsawood.
- Using the craft knife
and straight-edge, carefully cut out the vehicle body.
- Locate the straw from the kit.
Also get scissors and glue gun.
- Cut straw in half
- Using the glue gun, attach the
straws to the bottom of vehicle, one at each end (parallel to
- Locate the axles through each
- Push one wheel into each axle.
- Insert and axle through each
- Carefully place the remaining
wheel onto each axle.
Note: This completes construction of the basic solar vehicle.
- Locate the solar cell Panel
and the required parts for the propulsion system chosen gears,
pulleys, propeller, or rubber band. (Gears are supplied, Pulleys
and propellers are optional.
- Assemble and attach the
propulsion system as designed.
- Finish your solar racer as
desired using paint, markers, etc.
- Race the assembled vehicle on
a flat surface in a sunny day.
|If you don't have this
kit, you can order it now! It is available both as a single
pack and class pack. Kit content may be different from the
images shown in this page.