Page 1
EXPERIMENT MANUAL
WARNING — Science Education Set. This set contains
chemicals and/or parts that may be harmful if misused. Read
cautions on individual containers and in manual carefully. Not
to be used by children except under adult supervision.
Page 2
Safety Information
Dear Parents,
This experiment kit will introduce your child to the exciting world of solar technology. Equipped with this manual and the material
in this kit, your child could well be on his or her way to becoming a future engineer designing high-tech energy systems.
But first, it is natural to have concerns about safety. The experiment set in front of you conforms to U.S. and European safety standards. These standards include requirements for manufacturers, but they also require that parents stand by their children’s side
with help and advice. Please tell your child to read all directions and safety instructions and to keep them close at hand for easy
reference. Emphasize to your child that he or she should always follow all the instructions and rules of the experiments.
For performing experiments without solar energy, a 1.5-volt AA battery is required, which could not be included in this kit due to its
limited shelf life. Please be sure to remove any dead battery from the kit and dispose of it appropriately.
We wish you and your young solar hobbyist a lot of fun and success with these experiments.
Safety Warning for Parents:
• Warning: Intended exclusively for children at least 8 years of age!
Safety Warnings for Children:
• Do not insert the cables into an electrical outlet.
• Do not connect the motor box to other power sources.
• The experiment kit should not be connected to other energy sources.
• Do not charge non-rechargeable batteries.
• Different battery types or new and used batteries are not to be used together.
• Use only the recommended battery types.
• Always insert batteries with positive and negative ends in the proper direction!
• Dispose of dead batteries properly and without delay.
• Do not attach the connection clamps to each other.
• Safety equipment, such as components for restricting current, should not be tampered with.
First Edition. Franckh-Kosmos Verlags-GmbH & Co. KG, Stuttgart/2004
This work, including all its components, is copyright protected. Any use, outside the specific limits of the copyright law,
without the consent of the publisher is prohibited and punishable under law. This applies specifically to reproductions,
translations, microfilming, and storage and processing in electronic systems. We do not guarantee that all material in this
work is free from other copyright or other protection.
© 2004 Franckh-Kosmos Verlags-GmbH & Co. KG, Stuttgart
Text: Tobias and Reinhold Pehle
Project Manager: Gerhard Gasser
Photos: Medien Kommunikation, Unna, up to p. 6, p. 7 top: Kopf AG, Umwelt- und Energietechnik, Sulz-Bergfelden,
p. 11 bottom: HONDA, Deutschland; Inside back cover: public domain image courtesy of NREL.
Original Layout and editing: FROMM MediaDesign GmbH, Selters im Taunus
Second Edition, Thames & Kosmos LLC, Providence, RI, U.S.A.
© 2006, 2012 English Translation
® Thames & Kosmos is a registered trademark of Thames & Kosmos LLC.
Translation: David Gamon
Editorial and Production: Ted McGuire
Copy Editing: Jed Wilcox, Christa Raimondo, Stephanie McQuillan
Printed in Taiwan/Imprimé en Taiwan
PRINTED ON RECYCLED PAPER
Page 3
Experiment Manual
Tobias and Reihold Pehle
and David Gamon
Franckh-Kosmos Verlags-GmbH & Co., Stuttgart, Germany
Thames & Kosmos LLC, Portsmouth, RI, USA
Page 4
Kit Contents
6
1
9
12
2
3
20
21
10
13
7
8
11
14
22
16
4
5
15
23 24
28
17
29
18
30
19
26
25
27
The crane hook and the cord holder (28) have to be fastened to the cord.
2
Page 5
Contents List
Table of Contents
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Quantity and Description Part No.
2 x base plate
6 x long frame
6 x short frame
8 x short rod
6 x long rod
4 x large gear wheel
4 x medium gear wheel
10 x small gear wheel
4 x small sprocket wheel
4 x medium sprocket wheel
4 x large sprocket wheel
1 x large pulley wheel
1 x medium pulley wheel
1 x small pulley wheel
4 x tire wheels
5 x long axle shaft
2 x medium axle shaft
5 x short axle shaft
1 x engine shaft
1 x black cable
1 x red cable
1 x battery holder
1 x solar panel
1 x solar engine
5 x shaft plug
28 x anchor pin
2 x attachment plates
1 x crane hook
with spool
and cord
200 x chain link
1 x anchor pin lever
702 495
702 498
702 497
702 500
702 499
702 506
702 505
702 504
702 507
702 508
702 509
702 516
702 518
702 519
702 591
702 501
702 502
702 503
702 801
702 593
702 592
702 531
702 530
702 800
702 525
702 527
702 496
702 512
702 513
702 595
702 510
702 590
Tips and Tricks for Model Building and Experiments. . . 4
Follow the Instructions Closely ..................... 4
About Connecting Frames and Rods ................. 4
About Wheels and Pulleys ......................... 4
About Mounting Wheels .......................... 4
Understanding the Sun and Solar Power .............. 5
The Sun’s Energy ................................ 5
The Solar Engine ................................ 5
Where Does Our Energy Come From? ............... 6
History of the Solar Cell ........................... 7
How Does a Solar Cell Work? ...................... 7
Powering an Engine with the Energy of the Sun ....... 8
The Solar Module ................................ 8
Your New Solar Engine ........................... 8
Little Shadows .................................. 9
Artificial Clouds ................................. 10
Artificial Sun .................................... 10
The Artificial Sun’s Power ......................... 11
Ambient Light ................................... 11
Reverse Movement ............................... 12
Switching the Solar Module ........................ 13
Battery Power ................................... 13
Your First Solar Vehicle ............................ 14
Solar Tractor .................................... 14
Under the Artificial Sun ........................... 14
Driving in Reverse ............................... 17
A Drive in the Sunshine ........................... 17
A Drive on Bumpy Ground ........................ 18
A Downhill Drive ................................ 18
An Uphill Drive .................................. 19
Driving with the Battery ........................... 19
Your Engine’s Performance ........................ 19
Load and Speed .................................... 20
Conversion to a Transport Vehicle .................. 20
Adding a Load ................................... 21
Maximum Payload ............................... 21
Transporting a Load Uphill ........................ 21
Weight and Speed ............................... 22
For some of the experiments, you will also need:
>
l 1.5-V AA battery
l various lamps in the house, especially a desk
lamp with at least 75 Watts of illumination
l 1 sheet of tracing paper or transparent wax
paper
l even surface (e.g. tabletop or pavement)
l uneven surface (e.g. gravel path or lawn sur-
face)
l large, smooth, solid piece of cardboard (e.g.
back of a pad of 8 1/2 x 11-inch drawing or
writing paper)
l chunks of brick or rocks for a payload
l kitchen or postal scale
l small piece of cardboard (approx. 8 x 11 cm)
The Purpose of Chains ............................. 23
Drive Chains .................................... 23
Too Tight or Too Loose ........................... 24
Caterpillar Tracks ................................ 24
Driving Over an Obstacle ......................... 25
Driving Over Uneven Terrain ...................... 25
Large Platform Elevator ............................ 26
Your Solar Car ..................................... 30
Truck with Large Cargo Bed ........................ 34
Large Drawbridge .................................. 38
“Iron Annie” Airplane .............................. 43
Windmill with Wind Wheels ......................... 48
Mobile Crane Car .................................. 54
Heavy Duty Construction Crane ..................... 59
Designing Your Own Solar Models .................... 64
3
Page 6
Tips and Tricks for
Model Building and Experiments
Follow the Instructions Closely
With this experiment kit, you will assemble a variety of
solar models and conduct a lot of experiments. It is best to
assemble the models in order. Then, it will be easier for you
to construct the complicated models at the end. For all the
models, it is important that all the individual components
are put together properly. Only then will everything work
right. To help you with this, there is a picture corresponding to every step in the assembly process. The instructions
that go with the picture tell you exactly which pieces to use.
Following each piece mentioned in the instructions, there is
a number in parentheses. This is the number that you will
find in the overview of the kit contents on pages 2-3. So if
you aren’t quite sure which piece you are supposed to be
using, you can check on pages 2-3 to verify exactly which
piece it is.
About Connecting Frames and Rods
Frames (2, 3) and rods (4, 5) are
connected to each other with the help
of the anchor pins (26).
You can use the narrow side of the
anchor pin lever (30) to pull the
anchor pin (26) out again.
The basic construction of all of
the models consists of frames
and rods, which are connected
to each other with the help of
anchor pins. Some anchor pins
are already permanently mounted
to all of the frames and rods. But
for most of the connections, you
will need the red anchor pins
(26). They are simply inserted
into the holes of the frames and
rods and serve to ensure a secure
assembly.
To make it easier to remove
the anchor pins from the holes,
your kit comes with a small tool,
the anchor pin lever (30). It has
two different sides, marked “A”
and “B.” The narrow side with the
“A” serves to lever out the anchor
pins. The other side, marked with
the “B,” is wider. You can use it to
remove shaft plugs (25) from the
frames or rods.
With the help of the shaft plugs (25),
you can mount individual gear wheels or
sprocket wheels to frames or rods.
The shaft plugs can be levered out with
the broad side of the anchor pin lever.
About Wheels and Pulleys
In this box of solar experiments, you
will find four types of wheels: gear
wheels (6, 7, 8), sprocket wheels (9, 10,
11), pulley wheels (12, 13, 14), and tire
wheels (15). They all perform different
functions.
Gear and sprocket wheels are used
in all of the models. They have two
functions: first, they serve to transfer
the rotary motion of the solar engine
to other components. Second, they
are used to secure axles (16, 17, 18, 19)
so that they don’t slip. The tire wheels
are used to transfer the power of a
vehicle’s engine to the ground surface.
The pulley wheels serve to guide the
cord. In most cases, wheels and pulleys
are secured with the help of the axle
shafts (16, 17, 18). You can also attach
wheels and pulleys to the engine shaft
(19) or secure them individually with
the small red shaft plugs (25).
About Mounting Wheels
The axle shafts (16, 17, 18) and the engine shaft (19) each have two different
ends: one short and one long. On the
short end, wheels and pulleys can only
be pushed on a little way. But if you
push them onto the long end, you can
position wheels and pulleys wherever
you want on the shaft.
The short end is constructed in
such a way that the axle shaft can’t slip
through a hole. To secure an axle shaft
to a rod or frame, it will suffice to push
a wheel, sprocket, or gear onto the
long end to serve as a bracket. When
building a model, you have to pay close
attention to which direction an axle
shaft is inserted.
With all of the models, wheels and
pulleys have to be able to rotate freely.
Otherwise, the solar engine won’t be
able to turn them. For that reason, it is
very important that wheels and pulleys
have enough “play” — as the professionals call it — and not be mounted
too close to other components. So
always leave a little room between a
wheel or pulley and other components.
Then, everything will go smoothly.
Sometimes, it may be difficult to
remove a wheel from its axle. If that
happens, use another axle shaft as a
tool; hold the wheel tight and push
with the other axle shaft against the
axle that the wheel is mounted on (see
picture at right).
short end
long end
The short end of the axle
shaft (16, 17, 18) is built
so that the shaft can’t
slip through a hole.
If wheels or pulleys are
mounted too close to
other components, it is
hard to turn them.
If wheels have enough
“play,” they turn easily.
If a wheel is mounted too
tightly on an axle shaft,
you can push out the axle
shaft with another.
4
Page 7
Understanding the Sun
and Solar Power
The Sun’s Energy
Have you ever really thought about
what the Sun means to us, and what
it does for us? Let’s start right at the
beginning, or more precisely, let’s start
early…
What happens when the Sun rises?
It gets light out. The Sun produces
light — just like a lamp, except much,
much brighter. As you know, you need
electricity to turn on a lamp. Electricity
is a form of energy. We can use this
electricity in many different ways, just
one of which is illuminating a filament
in a light bulb. The Sun, on the other
hand, needs no electricity to create
brightness. Actually, it is just the opposite. The Sun is itself an energy source
that provides us with our daylight. Its
power is so great that not even all the
lamps in the world could produce as
much light as the Sun.
The energy from the Sun is called
radiant energy. About 600 million tons
of hydrogen are fused into helium
in the Sun’s interior every second,
producing a radiant energy of 63,000
kilowatt-hours per square meter
(kWh/m
kilometers, where the Earth orbits the
Sun, the power of this radiation still
amounts to 1,400 kWh/m2 (or Joules).
Only about half of that energy is
absorbed by the Earth, while the other
half is reflected back into space.
The Sun’s radiation is highly variable in different regions of the world.
That has to do with cloud cover and
the tilt of the Earth. In Pennsylvania,
about 1,000 kWh/m2 of solar energy
are available per year, while the figure
2
). At a distance of 150 million
is about 1,700 in Los
Angeles, 2,000 kWh/m
in the Caribbean, and
2,200 kWh/m2 in the
Sahara desert. Compare these numbers to
the fact that the average American uses only
about 13,500 kWh in a
whole year.
We can do some
calculations to find that
the Earth gets about
5.45 x 1024 Joules of energy from the
Sun every year. That’s 545 with 22
zeros after it! To put this in perspective, the amount of energy produced
and consumed in one year by everyone
on Earth is only about 4.26 x 1020
Joules. Thus, the Sun gives us about
13,000 times more energy than we
consume in a year! This means that in
less than an hour, the Sun delivers as
much free energy as all of the Earth’s
inhabitants combined use in an entire
year. So scientists have naturally asked
themselves the following question:
How can we capture the Sun’s energy
and use it for other purposes?
This is where the solar cell comes in.
A solar cell is a device that converts
sunlight into electrical current. The
word “solar” comes from the Latin
language, in which “sol” means Sun.
There are many ways that solar cells
can be used. In this experiment kit,
we will be using the Sun’s energy to
power a small motor used in various
models. Solar cell technology is also
called photovoltaic technology.
2
Solar cells make it
possible to convert
the Sun’s energy into
electricity. The Sun can
deliver 13,000 times
more electricity than
the entire world uses in
one year.
The Solar Engine
You are probably already familiar with
many kinds of engines, such as the
gasoline-powered engines in cars.
Those only run as long as there is fuel
in the tank. And you know about toy
cars that run on batteries, which will
run only until their batteries are used
up. Both of these kinds of engines
have major disadvantages. First of all,
fuel and batteries are expensive. On
top of that, they pollute the environment. Cars emit toxic and environmentally harmful gases. Used batteries get thrown into the trash. Since
they contain environmentally harmful
materials, they have to be disposed of
in time-consuming and labor-intensive
ways. In addition, they add useless
mass to our landfills.
Your solar engine, on the other
hand, needs neither gas nor batteries.
After it is made, it produces its own
electricity for free, for a long time. It
creates no toxic gas emissions, nor
does it add to the landfill. So a solar
engine is environmentally friendly as
well as inexpensive.
There is one small disadvantage
to a solar engine. In order to run, it
needs light — ideally, bright sunlight.
Since sunlight doesn’t reach us
at night, a solar cell can only produce
electricity from the Sun’s energy during the day. However, the electricity
produced by a solar cell from sunlight
can also be stored. To do that, you
need special rechargeable batteries and extra equipment. In order to
produce and store as much electricity
as possible in a photovoltaic installation, at the level that a family might
need, you need a lot of solar cells.
These are housed in large, flat panels
or modules, which you can already see
on some buildings.
5
Page 8
Where Does Our Energy Come From?
Most of the energy we use comes from the Sun, in one way or another. This table provides a lot of information about our
eight most popular energy sources, how they work, where they come from, and whether or not they are sustainable. Sustainable means that they can continue indefinitely without running out or causing other problems over time.
Name Examples Definition Energy Origin
Fossil Fuels
Hydro
Nuclear
Geothermal
Solar
Wind
Biomass/
Wood
Tidal
Gasoline in a car, oil in
a furnace, natural gas
stove, coal in a power
plant
Waterwheel used to grind
meal, hydro-electric
dam used to generate
electricity
Big reactors in power
plants and submarines
Geothermal power plants Geothermal power is generated using heat from
Photovoltaics (solar
cells) produce electricity,
solar water heaters heat
water, solar towers collect heat to turn turbines
to produce electricity
Windmills, wind power
generators
Sugar cane converted
into a combustible fuel,
animal waste converted
into methanol fuel
Turbines in tidal areas Tidal power is power from the movement of the
Fossil Fuels are organic materials that release a lot
of heat when they are burned. The heat can be used
to heat water to turn turbines to generate electricity.
They also produce a lot of pollution when burned.
Hydro power is simply power from falling water.
Today, it is mainly used in the form of dams that
trap water and funnel it through turbines to produce
electricity.
A complex system sets off a chain reaction of fission, or splitting, of uranium atoms. This produces
lots of heat, which is used to spin turbines which in
turn produce electricity.
deep inside the Earth to create steam which is used
to drive turbines to produce electricity.
Solar power is energy from the Sun. It can be captured and converted into useful energy in a variety
of ways. Without the Sun, there would be no life as
we know it on Earth. All living things need energy
from the Sun, either directly or indirectly, to survive.
Naturally occurring wind (moving air) is used to
turn turbines to generate electricity. In the past,
windmills turned wind power into mechanical
energy used to grind corn.
Biomass is an umbrella term used to describe any
organic, non-fossil material that can be used as
fuel. It is often plant and animal “waste” products
that are not useful for another purpose. Biomass
commonly used for fuels includes corn stalks, sugar
cane, wood by-products, animal manure and even
household waste.
tides in the ocean. It can be harnessed by placing
turbines in parts of the ocean with strong tidal currents. The currents turn the turbines that produce
electricity.
The remains of prehistoric plants
and animals, which grew and stored
energy from the Sun
The Sun evaporates water from the
oceans, the evaporated water rains
out of the sky to help form rivers
which run back to the ocean.
The energy stored in the bonds inside
uranium atoms
The temperature at Earth’s core is
estimated to be 5,000 to 6,000° C.
This heat was originally generated
when Earth formed, and additional
heat is formed as radioactive elements
decay inside the planet.
Nuclear fusion reactions in the Sun
fuse hydrogen atoms together into
helium atoms, yielding huge amounts
of energy.
Winds occur on Earth for two reasons.
First, the Sun heats the Earth in
different places at different times,
causing certain areas to have warmer
air than others. This causes pressure
differences, and air will flow from
areas of high pressure to areas of low
pressure. This, combined with the fact
that Earth rotates, causes the winds to
blow as they do.
Biomass grows because of energy
from the Sun, either directly as in the
case with plants, or indirectly, as in
the case with animals that eat plants
to grow.
The tides are caused by the gravitational pull of the Sun and the Moon
on the water in the oceans.
Percentage of world’s
power coming from
this source
Petroleum: 38%
Coal: 24%
Natural Gas: 24%
7% Yes
6% No, Earth has a
<1% Yes
<1% Yes
<1% Yes
<1% Yes, theoretically
<1% Yes
Is it renewable,
relative to
human life?
No, only over millions of years
limited amount of
uranium in it
biomass can be
grown at the rate
it is consumed
for fuel
Did you know . . .
. . . that the temperature on the
surface of the Sun is over 6,000° C
(about 10,800° F)?
In the center of the Sun, the temperature is 15-20
million ° C (~27-36 million ° F). The diameter of the
Sun, at 1,390,600 km, is over 100 times that of the
Earth. Its surface is 12,000 times as great as that
of our planet. The Earth itself would fit into the Sun
1,300,000 times. If you picture the Sun as a ball
20 m across, the Earth would be about the size of
a soccer ball 2 km away. The actual distance of the
. . . and that the
Sun is only middle-aged?
Even though the Sun is
estimated to be about 4.6
billion years old, scientists
calculate that it will continue to shine at its current
energy level for another 5
billion years. So the Sun’s
energy will be available for
human usage for a long
time to come.
Sun from the Earth is about 149,500,000 km.
6
Page 9
History of the Solar Cell
In 1839, the French physicist Alexandre-Edmond Becquerel
discovered that light can influence electrical processes. He
determined that metal electrodes immersed in acid produce
more electricity when they are placed in the sunlight. Later,
scientists named this the photoelectric effect, or photovol-
taic effect. This was a very important discovery because it
clearly showed that under certain circumstances, light can
be converted into electrical energy.
In 1883, an American inventor named Charles Fritts built
the first solar cell, but it was very inefficient. A lot of time
passed and a lot of research was done before the first modern solar cell was patented by another American named
Russell Ohl. In 1958, the U.S. sent the first solar-powered
satellite into space, showing how much photovoltaic technology had progressed in just over 100 years.
How Does a Solar Cell Work?
A solar cell is a flat device that uses an electronic component called a semiconductor to convert photons, or the
massless particles of light energy, into electrical energy. The
semiconductor creates a voltage, or difference in electrical
potential energy, between two surfaces when it is exposed
to light. You can think of it like a battery, which also has a
voltage between to points. This is just a brief explanation
of how a solar cell works. To explain it more thoroughly, we
must first discuss electricity.
The phenomenon of electricity is nothing more than the
movement of negatively charged particles, called electrons,
through a material, called a conductor. Electricity flows easily through some materials, like metal, and poorly or not at
all through other materials, like plastic. We have discovered
materials, like silicon, which are naturally poor conductors
in pure form, but can be treated to become better conductors under special conditions. These are semiconductors.
In a solar cell, electrons are excited into motion by
exposure to energy from light. The solar cell is designed to
make the electrons flow in a specific direction, creating a
negative pole on the side where there are more electrons
and a positive pole on the side where there are fewer electrons, or more “empty holes” for electrons. To achieve this
electron flow, pure silicon must be treated to become a better conductor. This is done by adding impurities, or other
elements, to the silicon, in a process called doping.
There are two layers of treated silicon in the solar cell.
Phosphorus is added to the first layer, resulting in an abundance of free electrons. Because electrons have a negative
charge, this layer has a negative charge, and is thus called
n-type doped silicon. The other layer is doped with Boron,
resulting in an absence of electrons, or more holes for electrons. This gives the layer an overall positive charge, and is
thus called p-type doped silicon (Figure 1).
The n-type silicon layer is positioned right next to the
p-type layer (Figure 2). All of the free extra electrons in the
n-type layer flow to fill up the holes in the p-type layer, creating an electric field. Right along the line where the two layers meet, something interesting happens: electrons are able
to move from the n-type layer into the p-type layer, but not
from the p-type layer into the n-type layer. This area where
cover glass
antiglare layer
top contact layer
n-type silicon
p-type silicon
bottom contact layer
Diagram of the layering in
a modern solar cell
n-type layerp-type layern-type layerp-type layern-type layerp-type layer
p-n junction
sun
contact layer
contact layer
n-type layerp-type layer
electron
electron
hole
sun
photons (sunlight)
free
electron
electron flow
load
(motor)
load
(motor)
electron flow
the two layers meet is called the p-n junction. You can think
of it like a hill, where electrons can easily roll down the hill
(to the p-type layer) but it is very hard for them to go back
up the hill (to the n-type layer).
When the cell is exposed to light, the energy from
the light excites the electrons in the p-type layer, and they
break free from their holes (Figure 3). With contacts and
wires attached to conduct electrons out of the p-type layer,
through a load (such as a light bulb or motor), and back to
the n-type layer, we now have a complete solar cell circuit.
When an electron moves, the hole it was previously sitting
in becomes empty, and another electron can easily move
into its position (Figure 4). And because electrons can only
travel in one direction through the p-n junction, they must
pass through the wire and load to get back to the n-type
layer. This creates the electric current.
This basic solar cell with one p-type layer, one n-type
layer, and one p-n junction is called a first generation photovoltaic. A second generation photovoltaic has many layers
and multiple p-n junctions, to absorb more light. There is
also a third generation photovoltaic, which does not use the
traditional p-n junction at all.
This is a simplified description and we encourage you
to find out more about how solar cells work from books, the
internet, and your science teacher.
7
Page 10
Powering an Engine
with the Energy of the Sun
Your experiment kit includes a battery holder (22)
The Solar Module
If you are going to be a solar engineer and make use
of the Sun’s energy, you first need a solar cell to convert light into electricity. In your experiment kit, you
will find a small solar module (23) with several solar
cells. They are integrated into the black strips located
under the protective layer of plexiglass. If you turn the
module over, you can see the individual
cells quite clearly. Your module is just
like the big ones that you see on
the roofs of houses, except
that it is smaller and can’t
produce as much elec-
tricity.
onto which the solar module is mounted. In the battery holder, the electrical current is passed on to the
two sockets located on top of it on the left and right.
The electrical cables (20/21) are inserted into these
sockets. One cable is red, and the other is black. So
the battery holder has two functions: it serves as
something to attach the solar module to, as well as
something that connects the electrical cables to the
module. You can connect all kinds of electrical equipment (the technical term is “electrical load”) — most
importantly, the motor — to these cables.
Your New Solar Engine
In our first experiment, we will use the Sun’s energy
to drive your kit’s engine and turn a small sprocket
wheel.
The solar module (23)
In order to pass on the power of the Sun, each of your
module’s two brackets has a round metal conductor.
It is through these two terminals that the positive and
negative current produced by the solar cells becomes
usable.
Experiment 1
> You will need: parts from the parts list (next
page, upper right)
Instructions
Insert the small gray engine shaft (19) with a small
sprocket wheel (9) mounted on it into the engine
(24). Secure the engine and the solar module (23)
with the battery holder (22) to the base plate (1),
as shown in the photo at the top of the next page.
Then connect the engine and battery holder with the
electrical cables (20/21). The red cable is the positive
The battery holder (22) isn’t just for mounting the module (23). The
cables that will supply the engine with electricity are also attached to it.
In most of the models, the small engine shaft (19) is inserted into the
solar engine (24) in order to transfer the engine’s power to the model.
8
Page 11
Parts List
1 x base plate 1 1 x small sprocket wheel 9
1 x engine shaft 19 1 x black cable 20
1 x red cable 21 1 x battery holder 22
1 x solar module 23 1 x solar engine 24
line and the black one is the negative line. Be sure to
pay attention to the plus and minus symbols on the
battery holder and the engine when you attach the
cables. Then take your model into bright sunlight and
orient the module toward the Sun. What happens?
Results
As soon as enough light falls on the solar module,
the engine will start to turn. Direct sunlight is bright
enough to get your engine going. In shade, it isn’t
bright enough — the engine won’t move. Light and
shadow are like the on-off switch for the solar engine.
The solar cell has the ability to convert light into
electrical current, and it is this electrical current that
drives the engine. The engine stops when not enough
light falls on the solar module. In your house — often, even right next to the window — the light isn’t
intense enough. The bigger a solar cell is, the more
current it can produce. It also makes a difference how
the solar cell is constructed. On your module, there
are just a few small solar cells that are only capable
of producing a little current. That is why your engine
needs a lot of light in order to turn.
IMPORTANT NOTE ABOUT LIGHT SOURCES!
Not all light sources produce enough light for the solar cell to
power the motor. We recommend at least a 75 Watt incandescent
bulb in a suitable desk lamp fixture. Fluorescent lights, flashlights,
and low-voltage halogen lights will not work well. Of course, the
Sun is much more powerful than household lamps and should be
used if possible.
Your first solar model turns the small sprocket wheel inserted onto the
engine shaft.
Little Shadows
It would be interesting to know just how much light
your solar module needs in order to run the engine.
Experiment 2
> You will need: your solar model from the previ-
ous experiment
Instructions
Set your solar model in bright sunlight so that the
engine turns. Next, hold your finger over the solar
cell. Does the sprocket wheel still turn? What happens
when you hold two or more fingers over the solar
module? Try adjusting the distance between your
fingers and the solar module.
In our first experiment, a small sprocket wheel (9) mounted on the
engine shaft is turned. Mount it so that it sits flush at the front.
Results
When you hold your finger over the solar module, it
creates a small shadow. The shadow in turn darkens
a small part of the surface of the panel in which the
solar cells are located. The rest of the panel still gets
enough light to run the engine. The more of the panel
that you cover in shadow with your fingers or hand,
the less light the solar cells get. When there isn’t
enough light, the engine won’t move.
9
Page 12
Your solar engine doesn’t only run in bright sunlight. It will also run on bright light from a lamp. Use a 75 Watt incandescent bulb in a desk lamp.
Artificial Clouds
You know the story: it’s a bright sunny day, then it
gets cloudy and the nice weather is over. You have to
go inside if the sky darkens with heavy black thunderclouds. And worst of all: your solar engine won’t work.
But why is it that the sunlight on an overcast day isn’t
enough to power the engine?
Experiment 3
> You will need: bright sunlight, your solar model,
a sheet of 8 1/2 x 11-inch transparent paper (white
tracing or wax paper)
Instructions
Hold the transparent paper over your solar module
while the engine is turning. Then fold the paper down
the middle and hold this smaller surface over the
solar cells. Fold the paper again and again, observing
what happens each time you hold it over the solar
module.
Results
When you hold the unfolded thin, transparent sheet
over the solar cell, enough light still gets through and
the engine still turns. When you fold it, the sunlight
has to get through another layer in order to reach the
solar cell. The more you fold the sheet, the more layers you create. Each layer absorbs some of the light.
When there are too many layers, there isn’t enough
light getting through to the cell and the engine stops.
When the sky gets overcast, the same thing happens. Layers of clouds come between the Sun and
the Earth. Enough light can still get through a thin
layer of cirrus clouds to power the solar model. But
not enough of the Sun’s rays can get to your model
through thicker layers of cloud cover.
Artificial Sun
As you know, light isn’t only produced by the Sun. A
lamp with an incandescent or halogen bulb can also
provide light. Will this kind of light also run your motor?
Experiment 4
> You will need: daylight, your solar model, an as-
sortment of lamps in your house
Instructions
On a bright sunny day, turn on several lamps in your
home, such as floor lamps, overhead lights, and desk
lamps. Hold your solar module directly under the
lamps. What happens?
Results
Your solar cells don’t just convert sunlight into electrical current. If a lamp produces enough light, it can
also run the solar engine. In that sense, lamps work
just like an artificial Sun.
Not all of the lamps in your house will provide
enough light. The incandescent bulbs in electric lights
have different levels of strength. The strength of these
kinds of lights are indicated in watts (W). A bulb with
60 watts creates much brighter light than one with 15
watts. Also, some lights use a reflector to focus their
light, creating greater brightness at a specific point.
Reflectors are usually silver-colored.
There are some kinds of lighting that have built-in
reflectors as well as ones that concentrate light.
Because there are so many different kinds of lamps
and lighting, one might be bright enough to run the
engine while another might not.
10
Page 13
The Artificial Sun’s Power
Ambient Light
Why doesn’t the solar engine run in every part of your
home — even in a particularly bright room? The next
experiment should shed some light on this.
Experiment 5
> You will need: solar model and a light in your
house that is strong enough to move the solar engine
when you hold the engine directly beneath it
Instructions
Hold your solar model directly under the light that
is strong enough to run the engine. Then gradually
increase the distance between the lamp and solar
module. What happens?
Results
The farther away you get from the lamp, the less light
is emitted from it. You can see that particularly clearly
on a street at night, when a car drives toward you with
its headlights on. When the car is still far away, all you
see is two small points of light. But when it drives
by you, the light of the car is much, much brighter.
Because the brightness of a light source drops with
distance, the solar cell won’t get enough light to run
the motor when it is too far away.
During the day, daylight enters your home. A term for
this kind of light is ambient light (literally meaning
“surrounding light”). In the next experiment, we will
see if ambient light has any effect on the solar cell.
Experiment 6
> You will need: solar model, a long ruler, a light
in your house that is strong enough to run the solar
engine when you hold the module directly beneath it.
A desk lamp works the best.
Instructions
In the middle of a sunny day, hold your model under a
light that is strong enough to run the engine. Increase the distance until the engine stops. There has
to be a lot of sunlight entering the room. Measure
the distance between the lamp and the model. Write
down the measurement. Repeat the experiment after
sundown and compare the distances measured. If
you don’t want to wait until evening, you can just shut
the blinds.
Results
During the day — even when the sky is overcast —
sunlight enters your house. The solar cell can make
Did you know . . .
. . . that there is a world championship for solar cars?
Every year, a solar car world championship is held in Australia. In the contest, the cars have to drive about 3,000 km
across the entire continent. The one that finishes first is the world champion. The fastest solar cars reach speeds of
over 100 km/h, driving on normal roads. During the race, the solar cars are accompanied by separate cars driven by
their team members. Most of the teams in the contest come from universities. Many of the electricians and mechan-
ics are students who take part in the race for fun. All the race cars are unique models, each one different from the next.
That means they are also very expensive. These solar race cars typically cost more than $300,000 to build.
The Honda Dream, a spectacular solar race car.
11
Page 14
You can change the rotation direction of the engine by reversing the
connections of the cables to either the engine or the battery holder.
use of this light. Even when just a little enters in, it
can be used to produce electricity. But most of the
time, it will be too weak to start the engine. The more
light that reaches the solar cell, the more electricity it
produces. Starting at a certain level of brightness, the
cell will produce enough electricity to run the engine.
During the day, sunlight combines with the light from
the lamp. That is why the engine runs at a greater
distance from the lamp than in the evening. After the
Sun sets, there is no more daylight and the light from
the lamp has to run the solar engine by itself.
Reverse Movement
Up to now, your solar engine has only run in one
direction. Now we’ll find out how to make it run in
reverse.
Experiment 7
> You will need: your solar model
Instructions
Run your model in bright sunlight. Watch the direction that the small sprocket wheel turns. Then remove
both electric cables from either the engine or the battery holder and plug them back in, but this time in the
opposite sides. Hold your model in bright light again.
What happens?
The rotation direction of the engine follows the direction of the flow
of current. The solar module producing the current determines its
direction of flow (see the text on p. 13).
If the solar module is turned around, the current flows in the opposite
direction. That makes the rotation direction of the engine change, too
(see the text on p. 13).
Results
After you reverse the cables, the wheel turns in the
opposite direction. That is because electrical current
always flows in just one direction. The engine rotates
in the same direction that the current flows. The
direction of flow can be changed by reversing the current supply — which is exactly what you do when you
switch the cables. It makes no difference whether you
switch them at the battery holder or the engine. The
direction of current flow is determined by the solar
cell. Remember what you read on page 7 about how
solar cells work?
12
Page 15
Switching the Solar Module
If it is the solar module that determines the direction
of the flow of current, it should be possible to change
the rotation direction of the engine by mounting the
module the other way around.
Experiment 8
> You will need: your solar model
Instructions
Run your model in bright sunlight. Note the direction
of rotation of the sprocket wheel. Mount the solar
module the other way around on the battery holder.
What happens?
Results
When the module is turned around, the electricity
flows in the other direction, which makes the engine
run in the opposite direction as well. If you want to reverse the direction of movement of a model — whether to make a vehicle go forwards and backwards or to
wind a cord up or down — it is easiest just to mount
the module the other way around.
If the Sun isn’t shining, you can also run your engine with a battery.
This should only be done when absolutely necessary, though, and not
as a rule.
Battery Power
The Sun only shines in the day — so it can’t run your
engine at night. That is why the engine also runs on a
battery, so you can still perform your experiments.
Experiment 9
> You will need: your solar model, a 1.5-V AA bat-
tery
Instructions
Switch out your solar module for a 1.5-V AA battery.
When you insert it, pay attention to the plus and
minus signs. Watch what happens.
Results
The battery turns the motor and the wheel just as well
as the solar module. Of course, the engine doesn’t
stop when you change the lighting, as it does with
the solar module. If you want to shut off the engine,
you have two options: either remove the battery from
the holder or pull out one of the cables. It makes no
difference whether you remove the cable from the
engine or the battery holder.
site direction when you reverse the orientation of the
battery. Or, of course, you can still switch the cables at
the battery holder or the engine.
Batteries cost money, get used up quickly and pollute
the environment. The Sun’s light, on the other hand,
is available in large quantities for free, and it doesn’t
pollute the environment. Therefore, whenever light
conditions permit, you should avoid using battery
power. It is only a solution of last resort. If you do use
batteries, it is best to use rechargeable ones, since
they are more environmentally friendly. Large solar
facilities, in fact, charge rechargeable batteries during
the day so that electricity is also available at night.
You can also change the rotation direction of the
engine in exactly the same manner as when it is running by solar power — the engine runs in the oppo-
The battery holder with battery
13
Page 16
Your First Solar Vehicle
Parts List
4 x long frames 2 1 x short frame 3
1 x short rod 4 2 x medium gear wheels 7
3 x small gear wheels 8 1 x small sprocket wheel 9
1 x medium sprocket 10 2 x long axle shafts 16
4 x tire wheels 15 1 x black cable 20
1 x engine shaft 19 1 x battery holder 22
1 x red cable 21 1 x solar engine 24
1 x solar module 23 8 x anchor pins 26
2 x shaft plugs 25
Solar Tractor
Your new solar engine works particularly well for powering vehicles. The first one we will build is a tractor.
Experiment 10
> You will need: the parts from the parts list, artifi-
cial Sun
Instructions
Carefully study the tractor assembly instructions on
the following pages and follow them to assemble your
model. You will need all the parts in the list on the
left.
Be careful to connect the parts exactly as shown in the
pictures. It is particularly important to count the holes
in the rods and frames so you insert the anchor pins
in exactly the right ones. For the tractor to run well, all
the wheels have to be able to turn easily. After assembling the axles and wheels, make sure that everything
has enough play (see page 5).
When you have finished assembling the tractor, hold
it under an artificial Sun, e.g. a desk lamp. Carefully
observe how the power of the engine is transmitted to
the other parts of your model.
The solar tractor works with a gear drive. The small gear wheel on the
engine turns the rear axle.
Results
The small sprocket wheel mounted on the small engine shaft drives the medium sprocket wheel on the
rear axle of the tractor. That turns the rear axle and
the large wheels attached to it. So the power of the
engine is transmitted through two sprocket wheels.
The teeth of both wheels are constructed so that they
mesh with each other precisely.
14
Page 17
1 2
1. Insert the engine shaft (19) into the solar engine (24). The short end
of the shaft goes in the engine block. Then mount a small sprocket
wheel (9) on the shaft.
2. The solar engine is mounted on a long frame (2). The engine’s
anchor pins go in the second, fourth, and sixth holes from the right.
3
3. From the other side, attach a second long frame (2) to the engine.
Press both frames together firmly, so the assembly is stable.
5
5. Another long frame serves to provide additional strength. This one is
set right on top of the two long frames with the engine.
4
4. The anchor pins on the long frames serve to attach another long
frame (2), which you mount vertically.
6
6. Now we’ll prepare the axles. Take two long axle shafts (16) and insert
a small gear wheel (8) over the short end of each one.
7
7. Push the two axle shafts through the outer holes of the frames at the
bottom. The gear wheels should be on the side away from the engine
shaft.
8
8. Insert a small gear wheel (8) and a medium sprocket wheel (10) on
the other side. The teeth of the sprocket wheel should mesh with those
of the wheel on the engine.
15
Page 18
9
9. Now mount the first two tire wheels (15) on the axle shafts. The
wheels should sit flush with the end of the axle.
10
10. Now mount one tire wheel (15) on each of the axle shafts on the
other side of the model.
12
12. Mount a short rod (4) on the top of the long frame sticking up
straight in the rear.
11
11. Align the wheels and axles as shown in the picture, and be sure that
the axles turn easily.
14 15
14. Take a short frame (3) and insert 8 anchor pins (26) into it as shown
in the picture.
+
—
13
13. The battery holder (22) with the solar module (23) goes on this short
rod. Pay attention to the “+/-“ signs.
15. At the front, your model will get two ornamental “headlights.” Start
by inserting two shaft plugs (25) into the frame.
16
Page 19
Under the Artificial Sun
In the next experiments, we will find out how strong
your engine is, and what kind of performance your
solar module can deliver.
Experiment 11
> You will need: your model, artificial Sun, smooth,
flat surface such as a table top
Instructions
Now place your tractor on a smooth, flat surface,
such as the top of a desk. Hold an artificial Sun
— e.g., a desk lamp — directly over the solar module.
Watch what the vehicle does.
Results
As soon as enough light strikes the solar module,
your tractor starts moving. When the tractor moves
beyond the cone of light, it stops: The solar module
isn’t getting enough light anymore.
16
16. Next, attach the “headlights”: Mount two medium gear wheels (7)
on the shaft plugs.
Driving in Reverse
If you attached the cables correctly, your vehicle
moved forward. Now we’ll make it go backward.
Experiment 12
> You will need: your model, artificial Sun, smooth,
flat surface
Instructions
Remove the solar module from the battery holder
and mount it the other way around, as shown in the
pictures on the left half of page 12. Place the vehicle
under the artificial Sun and let it move.
Results
When you turn the solar module, the direction of the
flow of current is reversed as well. So now the tractor
drives backward.
Experiment 13
> You will need: your model, artificial Sun, smooth,
flat surface
17
17. Now mount this small frame at the front of the model. The end with
the red anchor pins goes on top.
18
18. Now attach the cables to the engine. The red cable (21) attaches to
the positive pole, the black one (20) to the negative pole.
Instructions
Now switch the cables at the battery holder or the
engine. What happens?
Results
Your tractor drives forward again. When the cables
were switched, the direction of current flow was
reversed yet again.
19
19. When you attach them to the battery holder, make sure that the red
one goes to the positive side and the black one goes to the negative
side.
17
Page 20
On a bumpy surface, little rocks or twigs can create obstacles for your
model. Unfortunately, its engine isn’t powerful enough to overcome
them.
On a smooth surface, your solar vehicle runs flawlessly. Of course, the
Sun has to be shining brightly enough.
A Drive in the Sunshine
In the next experiments, we will see how your tractor
drives in the sunlight.
Experiment 14
> You will need: your model, bright sunlight, the
back side of a large 11 x 17-inch pad of drawing paper
or other large, solid, smooth piece of cardboard
Instructions
Lay a pad of drawing paper with its back side up, or
some other smooth, strong cardboard, in bright sunlight. Orient the module toward the Sun. Be sure that
the cardboard is lying flat. Then let your solar tractor
drive on it.
Results
As soon as enough sunlight hits the solar module,
the engine starts to run, which turns the axles and the
wheels. The power of the sunlight is enough to run
your tractor on a smooth, even surface — your tractor
is running on solar power.
A Drive on Bumpy Ground
Up to now, you have only run your vehicle on a
smooth surface — the back side of the drawing pad.
Now we’ll see how it does on a bumpy surface.
Experiment 15
> You will need: bright sunlight, solar model, level
but bumpy ground (e.g. a level gravel path or a lawn
that isn’t too steep)
Instructions
Let your solar tractor run in bright sunlight on a
bumpy surface. Make sure that it isn’t going uphill or
downhill. How does it perform now?
Results
Your tractor either won’t start correctly or won’t move
at all. As soon as the tires hit any little obstacle, you
have to give the model a push to get it moving again.
The engine isn’t powerful enough to overcome these
little obstacles. The solar cells simply produce too little electricity to drive the tractor over level but bumpy
ground. The same goes for all of the model vehicles
in this experiment kit. In order to get the models to
run well on bumpy ground, you would need much
larger and more powerful solar cells. But they would
be very costly.
A Downhill Drive
You know from riding a bicycle that you have to use
much less energy to go downhill. Does the same apply to your solar vehicle? You will find out in an experiment on an “inclined plane.” An inclined plane is a
firm, flat surface that can be used to make a downhill
slope.
Experiment 16
> You will need: light, solar model, large drawing
pad or other strong cardboard
Instructions
Let your solar tractor drive down the inclined plane.
Use the back side of a drawing pad, lifting the end of
18
Page 21
the drawing pad just a little. What happens when the
tractor goes downhill?
Results
Your tractor runs easily downhill. If you watch carefully, you will see that it even goes a little faster than
when you hold the cardboard level. On a downhill
drive, the engine has to expend less energy. Can you
use this effect to get your tractor to drive on a bumpy
surface?
Experiment 17
> You will need: bright sunlight, solar model,
bumpy ground that drops away (e.g. gravel path, paving stone with rough surface, or lawn)
Instructions
Run your solar model in bright sunlight down a
slightly sloping, bumpy surface. How does its performance change?
Results
When it’s going downhill, your solar vehicle moves
along quite easily. The bumps in the ground no longer
present any serious obstacles. The engine power is
the same as when it drives over flat, bumpy terrain,
but with the downward slope the engine doesn’t
have to expend as much energy to drive the tractor.
Instead, it can use its power to move the tires over
little obstacles.
So the speed depends on the slope. Or, put differently: with a slope, the engine’s force has to be applied
not only to moving the tractor forward, but to moving
it upward as well.
Driving with the Battery
So far, we have been running the tractor on solar
energy. Now let’s see whether its driving performance
changes when we use the battery instead of the solar
module.
Experiment 19
> You will need: solar model, battery, large drawing
pad or other strong cardboard, flat and slightly sloping bumpy ground
Instructions
In your model, switch out the solar module for the
battery. Make sure that the battery is fully charged.
Carry out experiments 14 through 18 one more time
and observe how the vehicle performs.
Results
The driving performance of your model hardly
changes. The engine runs just as well with the energy
of the solar module as it does with the energy of a
1.5-volt battery.
An Uphill Drive
From riding a bicycle, you not only know that it’s a
lot easier to go downhill, but also that you need a lot
more energy to go uphill. If it’s too steep, you even
have to get off and walk. The strength of your body
is no longer enough to conquer the incline. Is it like
that with your solar model too? We’ll use the inclined
plane to investigate that, too.
Experiment 18
> You will need: light, solar model, large drawing
pad or other strong cardboard
Instructions
Have your tractor drive up an inclined plane. Use the
back side of a drawing pad. During the drive, slowly
lift the front end of the drawing pad. What happens
when the solar tractor drives uphill?
Results
When your tractor drives uphill, it goes slower. And
when the slope is too great, it won’t move. The power
of the engine is not enough to turn the wheels.
Your Engine’s Performance
The engine and solar module in this experiment kit
are not strong enough to make fast, powerful vehicles
— like those remote-controlled cars that run on big
rechargeable batteries. For that, you would need
much larger and more expensive solar modules.
But the photo cells are good enough to power a vehicle in bright sunshine on flat, even ground or down
a bumpy slope.
Your engine is not without power, though. In the next
experiments, we will find out what it is capable of.
19
Page 22
Load and Speed
Conversion to a
Transport Vehicle
Experiment 20
> You will need: solar tractor, 1 x base plate (1), 2 x
short frame (3), 8 x anchor pins (26), bright sunlight,
smooth and even surface
As you know from sports, force can be applied in
many different ways — to lift weights, for example, or
to run fast. It’s the same with your solar engine. The
two most important jobs that a vehicle engine does
are to transport objects and to create speed.
In order to transport objects, your solar vehicle needs
a cargo bed. For that, we will first have to rebuild your
tractor a little.
Instructions
Rebuild your tractor into a transport vehicle by adding on a large cargo bed as shown in the pictures on
these two pages. Run your transport vehicle in bright
sunshine on a smooth, even surface — for example,
the back side of a large pad of drawing paper. What
happens?
With just a few parts, you can convert your tractor into a transport
vehicle. A base plate serves as the large cargo bed.
1
1. Insert four anchor pins (26) into each of the long side frames on both
sides of the vehicle. Attach the pins to the upper and lower portions of
the frames as shown in the picture.
2
2. Now hang a short frame (3) on the four anchor pins on one side of
the vehicle. The lower end of the short frame should align flush with
the lower section of the long frame.
20
Page 23
Results
The parts that you have assembled have only a modest weight to them. Simply converting the tractor to a
transport vehicle should not have changed its driving
performance yet.
Adding a Load
Now let’s find out how much weight your first solar
vehicle can handle. We can only determine how
strong your solar transporter is by loading weights
onto its cargo bed. The technical term is “payload.”
Experiment 21
> You will need: light, solar transporter, level
ground, blocks or small stones as payload
Instructions
Collect a variety of things that you can use to load
your vehicle, such as wooden blocks or small rocks.
Start with light objects. Check to see if your solar
transporter can carry the load. Keep increasing the
weight. What happens?
Results
Your solar transporter can easily carry light objects.
The more weight you add to the platform, the harder
it is for the vehicle. When you load on too much
weight, the engine can’t carry the payload — your
vehicle stays put.
Maximum Payload
Of course, it would be interesting to know exactly
what the maximum payload is for your transport vehicle. To determine that, you will need a kitchen scale.
Experiment 22
> You will need: light, solar transporter, level
ground, blocks or small stones as payload, kitchen
scale
3
3. Hang a short frame (3) on the four anchor pins on the other side as
well. The two short frames should be positioned exactly across from
each other at the same height.
Instructions
Find out what the maximum weight is that your solar
car can carry and how much weight will overburden it.
To do that, weigh the payload with your kitchen scale
before loading it onto the cargo bed. Keep increasing
the weight of the load until the engine isn’t strong
enough to move the vehicle. Write down your findings.
Results
Your model is pretty strong. In bright sunlight and on
an even surface, it can pull up to 500 grams (about 1
lb.) of weight.
Transporting a Load Uphill
When you were investigating the driving performance
of your tractor, you learned about the considerable
influence that inclines and declines can have. In the
next experiments, we will determine whether slopes
can also have an influence on payload.
Experiment 23
> You will need: light, solar transporter, large draw-
ing pad, blocks or small rocks as payload
4
4. Now attach a base plate (1) to the top. It should extend right up
to the short vertical frame at the front. On each side, the base plate
should be positioned over a row of holes.
Instructions
Have your model drive up a slightly inclined plane.
Vary the payload and observe what happens.
21
Page 24
Results
Your solar transporter can’t carry as big a payload uphill as it can on level ground. Since it is going uphill,
it not only has to move the weight in the driving direction, but also upward. So the slope has a considerable
influence on its maximum payload.
Experiment 25
> You will need: light, solar vehicle, a long mea-
suring tape, a stopwatch (you can also use a regular
watch if it has a second hand), paper and pen, a firm,
flat surface (for example, an asphalt sidewalk), bright
sunlight
Experiment 24
> You will need: light, solar transporter, large draw-
ing pad, blocks or small rocks as payload
Instructions
Now have your model drive down a slightly downhill
slope. Try changing the payload and see what happens.
Results
Going downhill, your solar transporter can carry an
even heavier payload than when it drives on level
ground.
Weight and Speed
In the next experiment, we will investigate the effect
that weight has on the vehicle’s speed. Speed is an
indication of how much time an object — a car, person, or even a rolling ball — takes to cover a certain
distance. If you want to determine speed, you therefore have to know the precise values of two things:
the distance covered and the time. If, for example, a
car drives 50 kilometers per hour (km/h), that means
it drives a distance of 50 km in exactly one hour. If we
want to determine the precise speed of your solar car,
we will need a watch to measure time and a measuring tape to measure distance.
Instructions
Mark off a distance of 1 m on the ground. Be sure that
the ground is flat and that your car won’t be driving
uphill or downhill. With a stopwatch, measure the
amount of time that your model takes to cover the
distance of 1 m when it isn’t carrying a payload. Note
down the number. Repeat the experiment with various
amounts of payload and compare the time values.
Results
The more payload you add to the cargo bed, the
slower your vehicle becomes. So there is a direct relationship between weight and speed. You know this
relationship from your everyday life: You can walk a
lot faster when you aren’t carrying anything. The more
weight you carry, the less power is available to produce speed. It’s exactly the same with engines: their
power can either be applied to transporting a payload
or to driving fast.
The power of a vehicle’s engine is indicated in kilowatts (kw). Truck engines often produce as many kw
as the engine of a Formula One race car. Of course,
they are built quite differently. With trucks, the power
of the engine is used to transport as large a payload
as possible. With race cars, on the other hand, the
most important thing is to drive as fast as possible.
As a result, they can only carry a small payload.
With most of the cars you see on the street, the power
of the engine is geared in a variable way. This allows
them to carry a relatively large payload or climb a
steep hill in one gear, and drive very fast in another
gear.
22
Your solar transporter can’t drive as quickly with a heavy payload as
without one. The engine has to expend its force carrying the load.
Page 25
The Purpose of Chains
Joining the links can be difficult, and will require a
Drive Chains
Your solar transporter is moved by a gear drive. In the
next experiment, we will take a look at another kind
of technology used for transferring the force of the
engine, namely a chain drive.
Experiment 26
> You will need: solar transporter, 53 chain links
(29), medium-sized sprocket wheel (10)
Instructions
Rebuild the solar transporter exactly as shown in the
pictures on this page. When you connect the chain
links, listen for two clicks as each link is attached to
the next one. The links have two different sides: one
is smooth, the other a little uneven. Connect the links
so that the smooth side is on the outside. Before
closing the chain, wrap it around the sprocket wheels.
little patience. All of your chain links are black. In the
illustrations, some of the links are colored so that you
can easily tell them apart from the other things in the
photos.
After assembly, take your model for a drive in bright
sunshine. Pay attention to the way the engine’s force
is transferred through the chain.
Results
You are already familiar with the principle of the chain
drive from your bicycle, which also transfers force
from your pedals to the rear wheel by way of a chain.
A chain drive is more complex than a gear drive
— you need more parts and the mounting process is
a little more difficult. So what is the advantage of the
chain drive? The answer is simple: with a chain, the
force can be transferred over a greater distance. With
a gear drive, both gear wheels have to be placed right
next to each other, whereas with a chain drive they
can be mounted far apart.
1 2
1. Remove the wheels from the side with the engine. Then push the
small sprocket wheel as far as possible toward the end of the engine
shaft. Place a medium-sized sprocket wheel (10) on the front axle.
3 4
3. Wrap the chain around the small sprocket wheel on the engine shaft
and the medium sprocket wheel on the front axle. The chain should
not be too tight or too loose.
2. Assemble a chain from 53 chain links (29). Spread it out with the
smooth side up. Each chain link has to snap into place twice when you
connect it to the next one.
4. Now mount the two wheels again. Check that the chain drive moves
easily and the vehicle runs smoothly.
23
Page 26
Too Tight or Too Loose
The chain drive works well because the chain is just
the right length. But what happens when the chain is
too tight?
Experiment 27
> You will need: solar transporter
Instructions
Remove one chain link. What happens?
Results
The chain pulls with difficulty, and even bends the
axles a little. When that happens, the axles lose their
play and can’t turn easily. The engine’s power is no
longer enough to move the vehicle.
And what about the opposite? What effect does a
chain have if it’s too long?
Experiment 28
> You will need: solar transporter, at least five extra
chain links (29)
Instructions
Lengthen the chain by five links to 58. What happens
now?
Results
The engine does run, and the chain drive works, but
the chain flops around. There is a risk that it might
get tangled up and twisted, and jump off the sprocket
wheels. Then, your model would certainly not work
well any longer.
So when you assemble your models, be sure that
the chain is neither too tight nor too loose. That will
ensure that they will run well.
Caterpillar Tracks
Chains can be used for other things besides drive
chains. With many kinds of vehicles, they take the
place of regular wheels. Examples of this are caterpillar tractors, dredgers, or some military vehicles.
Chains that are used instead of wheels to move a
vehicle across the ground are sometimes called caterpillar tracks. We will try switching out the wheels for
caterpillar tracks and then compare the performance
of the tracks with that of the wheels.
24
To equip your vehicle with caterpillar tracks, remove the cargo bed and
switch out the tires for large sprocket wheels.
1
1. First, remove the four wheels. The tires will be replaced by sprocket
wheels and caterpillar tracks.
2
2. Then dismantle the cargo bed, removing the base plate and the two
short frames supporting it. Also pull out the eight anchor pins from the
large frames.
Page 27
Experiment 29
> You will need: solar transporter, 140 more chain
links (29), four large sprocket wheels (11)
Instructions
Convert your solar transporter into a caterpillar track
vehicle, as shown in the pictures on these two pages.
You will just need chain links (29) and the large
sprocket wheels (11). You will have to remove the
cargo bed, because otherwise one side of its support
framework would interfere with the mounting of the
caterpillar track. Then take your model for a drive in
bright sunlight. What do you observe?
Results
At first glance, your caterpillar track vehicle drives
just like a vehicle with wheels. Under normal driving
conditions, there do not seem to be any significant
differences between vehicles with caterpillar tracks
and ones with wheels.
Driving Over an Obstacle
Caterpillar track vehicles show their strengths most
clearly when driving over uneven terrain. We will see
that in the next experiment.
Experiment 30
> You will need: your solar-powered caterpillar
track vehicle, smooth, even, slightly down-sloping
surface (for example, a tilted drawing pad), a long
crayon or pencil
Instructions
Lay a long pencil or crayon across the path of your
caterpillar track vehicle to serve as an obstacle. Let
your vehicle get a running start and drive over the
obstacle, while you hold the pencil or crayon in place.
Pay close attention to what happens with the tracks
as they roll over it.
Results
As they roll over the pencil, the links of the chain wrap
themselves around the obstacle. So the chain adjusts
itself to fit the uneven ground. That improves the traction of the entire vehicle — it doesn’t slip the way a
car with wheels would do.
3
3. Now mount the four large sprocket wheels (11) on the ends of
the axles. Be sure that both sprocket wheels are positioned exactly
opposite each other, forming a straight line, on both sides of the
vehicle.
4
4. Make two chains of 70 chain links (29) each. Wrap the chains
around the large sprocket wheels. Check that everything moves
smoothly and easily.
Driving Over Uneven Terrain
Now let’s see how your caterpillar track vehicle handles when driving over a lot of obstacles, as it would
encounter if the terrain were uneven.
Experiment 31
> You will need: your solar-powered caterpillar
track vehicle, several long crayons or pencils, bumpy,
slightly down-sloping ground
Instructions
Now lay several pencils on the surface at an angle, so
that when one track is on the ground the other will
be rolling over a pencil. Hold the pencils in place.
Observe how the tracks behave.
Results
The caterpillar tracks accommodate themselves
very well to the uneven surface and compensate
for bumps. If the obstacle is too large, however, the
vehicle gets stuck.
The inventors of the caterpillar track copied this principle from nature: caterpillars also move similarly to
these tracks. That is why the treads are called caterpillar tracks, and why the vehicles are known as caterpillar track vehicles.
25
Page 28
Large Platform Elevator
Raising and Lowering
with the Sun
The solar engine can be used for other things besides driving a vehicle forward and backward. With
this model, we will be applying solar energy to the
raising and lowering of a platform. You will be using
the crane hook, cord, and spool (28). You first have
to attach the cord to the spool and hook (see the
pictures on p. 2). The spool will be mounted directly
on the engine shaft. When you are working with the
crane hook, cord, and spool, be sure that the cord
doesn’t get tangled on the axles when it is wound up.
Most important of all, be sure to stop the platform
at the right time when you are raising or lowering it.
The simplest way is to hold your hand over the solar
module to prevent the cells from getting enough light.
(Model Car)
Components of the Model
This large model, which is quite easy to build, actually
consists of three parts. First, there is the tall support
structure, assembled out of long and short frames. It
is mounted securely on two base plates, which form
its foundation. On top of the framework, there is
the drive system. In addition to the engine, the solar
module is mounted here. You will need a special support frame for both.
The third element is the elevator cage. This is constructed from frames and rods, with two medium
gear wheels inserted into the front for decoration.
The cage is suspended directly from the crane hook.
In order for the load to sit securely in the cage, it is
recommended that you cut out a piece of cardboard
to fit on the bottom of the cage. Any sturdy cardboard
will do, but colored cardboard looks particularly nice.
If you like, you can also build a small car that you can
move up and down with the model. Of course, you
can also raise and lower other objects — e.g., toy
cars, toy figures, or building blocks. Try to figure out
how much weight your platform lift can handle.
26
The large platform lift consists of a support framework, lift system, and
elevator cage.
Page 29
Parts List
2 x base plates 1 6 x long frames 2
6 x short frames 3 5 x short rods 4
2 x long rods 5 2 x medium gear wheels 7
1 x small gear wheel 8 1 x small sprocket wheel 9
1 x large sprocket wheel 11 1 x long axle shaft 16
1 x engine shaft 19 1 x black cable 20
1 x red cable 21 1 x battery holder 22
1 x solar module 23 1 x solar engine 24
2 x shaft plugs 25 21 x anchor pins 26
2 x attachment plates 27
1 x crane hook with spool and cord 28
1 piece of sturdy cardboard (8 x 11 cm)
1
1. The foundation consists of two base plates (1). Combine these into a
single surface with the attachment plates (27).
3
3. Attach two long frames (2) to one short frame (3) with two anchor
pins (26). Insert four more anchor pins (26) into the short frame.
2
2. Next, connect two long frames (2) to make each of the two tall
framework sections and mount these on the foundation. Pay attention
to the holes the frames are mounted in.
4
4. Now mount the “U,” which you just constructed out of the two long
frames and the short one, onto the two tall framework sections.
27
Page 30
5
5. Now you will construct the lift system. Insert four anchor pins into
two long rods (5) and insert a long axle shaft (16) through the center of
one rod.
6
6. Push a sprocket wheel (11) onto the axle shaft and guide the shaft
through the second long rod. Now attach two short rods (4) with two
more anchor pins (26).
7
7. Next, attach another short rod (4) to the anchor pins on the short
rods you just mounted. Also, push a small gear wheel (8) onto the
shaft.
9 10
9. Now attach the battery holder (22) to the short rod on the left,
mount the solar module (23), and attach both electricity cables (20/21).
Then attach the crane spool (28).
8
8. Insert the engine shaft (19) into the solar engine (24). Mount a small
sprocket wheel (9) onto the shaft. Mount the engine so that the small
sprocket wheel moves the large sprocket wheel.
10. Next, mount the lift system onto the top of the support framework.
The short rod on which the engine is mounted should sit flush with the
front of the framework.
28
Page 31
11
11. The floor of the cage is made of two short frames (3) connected by a
short rod (4). You will need to use two anchor pins (26).
12
12. Each of the side walls consists of one short frame. Take two short
frames (3) and insert six anchor pins (26) as shown in the picture.
13
13. Now insert the two short frames into the floor. A short rod (4)
connects the frames at the top for stability.
15 16
15. Place the cage in the elevator shaft and add the short frame from
the last step. Two medium gear wheels (7) go on the shaft plugs. A
piece of cardboard (8 x 11 cm) will strengthen the floor.
14
14. One more short frame (3) prevents the cargo from falling out of
the cage. Insert two shaft plugs (25) and one anchor pin (26) into the
frame.
16. Finally, suspend the cage from the crane hook. The hook itself
should hang from the center hole of the small rod lying across the top
of the framework.
29
Page 32
Your Solar Car
Solar Car Assembly
This solar car is actually pretty complicated to build.
It is relatively wide, so the front and rear axles and
the drive shaft have to be made out of two axle shafts
joined together in order for them to be long enough.
When lengthening the axle shafts, the important thing
is to have the short ends of the shafts located on the
inside. They are inserted into a small sprocket wheel,
which holds them together. Be sure that the ends
of both axle shafts are pushed equally far into the
sprocket wheel, so the sprocket wheel is positioned
exactly between the two shafts. Finally, check to make
sure everything holds together solidly.
Parts List
6 x long frames 2 3 x short frames 3
4 x short rods 4 4 x large gear wheels 6
3 x medium gear wheels 7 9 x small gear wheels 8
4 x small sprockets 9 2 x medium sprockets 10
1 x large sprocket 11 4 x tire wheels 15
5 x long axle shafts 16 1 x medium axle shaft 17
1 x short axle shaft 18 1 x engine shaft 19
1 x black cable 20 1 x red cable 21
1 x battery holder 22 1 x solar module 23
1 x solar engine 24 4 x shaft plugs 25
18 x anchor pins 26 43 x chain links 29
30
Your solar car operates with a combination gear and chain drive. The engine turns a drive shaft by way of the two outer sprocket wheels, from which
the force is transferred to the rear axle by way of a chain.
Page 33
1 2
1. Two long frames (2) connected together serve as the side sections.
Then insert four anchor pins (26) into the frames and attach a short
frame (3).
2. Now mount another long frame (2) on the anchor pins in your large
side section. Insert two more anchor pins (26) into this frame.
3
3. A long axle shaft (16) goes into the fourth hole of the frame. Place a
small gear wheel (8) onto one side and a medium gear wheel (7) onto
the other side. Then, put a small sprocket wheel (9) onto the long end.
5
5. For the rear axle, insert a long axle shaft (16) into the fourth hole
from the right. It is secured with a small gear (8) and a medium
sprocket wheel (10).
short ends
4
4. The axle is lengthened with another long axle shaft (16). The axle
shaft’s short end goes into the small sprocket wheel.
6
6. You will have to lengthen the rear axle as well. Slide on a small
sprocket wheel (9) and then insert a long axle shaft (16).
7
7. Now, mount the drive shaft. It is secured to the frame by a small
gear wheel (8) and a small sprocket wheel (9).
8
8. The drive shaft has to be lengthened too, although just with a
medium axle shaft (17). The two shafts are held together with a small
sprocket wheel (9).
31
Page 34
9
9. The grill is made of a short frame (3) into which you stick two anchor
pins (26), one short axle shaft (18), and three shaft plugs (25).
11 12
11. Two more small gear wheels (8) go on the rear side. Stick one on
the axle, and attach the other to the second hole from the right with
another shaft plug (25).
10
10. Stick two small gear wheels (8) and two medium gear wheels (7)
onto the small axle and the three shaft plugs.
12. Now you will mount the small frame to the front end of the double
frame. Rotate the axle and make sure that all of the gears move easily.
32
13 14
13. Assemble the second side section out of three long frames (2), just
like the first one. You will be using eight anchor pins (26) in all.
15 16
15. Now connect the two side sections. Be sure to insert the axles into
the right holes and check that they turn easily.
14. Now attach the solar engine (24) to the upper frame. Make sure
that the engine sits in the right holes. Then insert the engine shaft (19).
16. Stick one small gear wheel (8) onto the free end of each of the front
and rear axles (two gear wheels total).
Page 35
17
17. Now mount the four tire wheels (15) onto the front and rear axles.
For looks, add a large gear wheel (6) to the outside of each one.
19 20
19. At the front, a short rod (4) stabilizes the construction. It attaches
to the two upper frames by the two anchor pins (26).
18
18. For the power transmission between engine shaft and drive shaft,
mount a medium sprocket wheel (10) on the engine shaft and a large
sprocket wheel (11) on the drive shaft.
20. The lower chain is made out of 43 chain links (29). Before attaching
it, adjust the two sprocket wheels so they form a straight line.
21 22
21. At the rear as well, reinforce the construction with a short rod (4)
attached to the two long upper frames.
23 24
23. Then attach this structure at the front to the two long upper frames.
You will have to push the two rods out a little bit.
22. For the front section, connect two short rods (4) with one short
frame (3). You will need to use two anchor pins.
24. Finally, mount the battery holder (22) with the solar module (23) to
the frames at the front. Then connect the electricity cables (20/21) to
the engine.
33
Page 36
Truck with Large Cargo Bed
Undercover Technology
This truck has command of a pure chain drive that
turns the wheels on the rear axle. The unusual thing
about it is that the transmission to the rear axle is
practically invisible. Only the chain from the engine
to the drive shaft is visible — the other chains are
hidden by the large cargo bed. The big headlights on
the front grill turn when the truck is moving. They are
set in motion by the front wheels, and have no direct
contact with the engine. The yellow gear wheels move
in reverse of the vehicle’s motion: while the truck is
driving forward, they turn in the opposite direction.
Another special feature is the vehicle’s moveable front
end.
Parts List
2 x base plates 1 4 x long frames 2
6 x short frames 3 6 x short rods 4
2 x long rods 5 2 x large gear wheels 6
4 x medium gear wheels 7 10 x small gear wheels 8
4 x small sprockets 9 3 x medium sprockets 10
4 x tire wheels 15 4 x long axle shafts 16
2 x medium axle shafts 17 2 x short axle shafts 18
1 x engine shaft 19 1 x black cable 20
1 x red cable 21 1 x battery holder 22
1 x solar module 23 1 x solar engine 24
3 x shaft plugs 25 24 x anchor pins 26
121 x chain links 29
2 x attachment plates 27
34
On this truck with a big cargo bed, it isn’t just the tires that turn: The gear wheels on the front grill are also rotated by the front axle.
Page 37
short end
1 2
1. Start with a long frame (2), three anchor pins (26), one medium (17)
and one long axle shaft (16), one small gear wheel, and one medium
sprocket wheel (10).
short end
2. Equip a second long frame (2) with the same components, except
use a small gear wheel (8) instead of the medium sprocket wheel.
3
3. Now you will combine the two frames together. Connect the axle
shafts with one medium sprocket wheel (10) and one small sprocket
wheel (9) to form two long axles.
5
5. For the other end’s attachment section, use four anchor pins (26) to
mount two short rods (4) to another short frame (3).
4
4. Now connect the two side sections with a short frame (3) and align
the gear wheels on the axles.
6
6. Now attach the second frame to the side sections. The two small
crossways-mounted frames serve to stabilize the structure.
7
7. The two base plates (1) form the cargo bed. They are connected with
the two attachment plates (27) into a single continuous surface and
then placed on the framework.
8
8. Insert three anchor pins (26) into each of two long frames (2). Attach
the engine (24) with engine shaft and a small sprocket wheel (9) to the
rear frame.
35
Page 38
9
9. Attach the two frames to the short rods. They hold the cargo bed in
place, which can now no longer move up or down.
11 12
11. A short axle shaft (18) with a medium (10) and a small sprocket
wheel (9) forms the drive shaft. Insert the shaft into the frame five
holes above the axle shown at the bottom of the picture.
10
10. Next, place two long rods (5) on the rear of the base plate and push
them onto the side anchor pins. Now the cargo bed definitely won’t be
able to slip.
12. Two tire wheels (15), two small gear wheels (8), and two medium
gear wheels (7) complete the axle. After assembly, make sure that the
axle shafts turn easily.
36
13 14
13. Align the sprocket wheels to form a straight line. Then attach the
drive chains. They are made of 31, 44, and 46 chain links (29).
15 16
15. Mount two large gear wheels (6) on the front of the frame, and on
the back mount one more small gear wheel (8). Check over the entire
gear drive assembly.
14. A short frame (3) makes the radiator. Three shaft plugs (25) and one
short axle shaft (18) with two small gear wheels (8) are inserted into it.
anchor
pins
16. In each of two short frames (3), insert two anchor pins (26). In
addition, insert two medium gear wheels (7) onto two long axle shafts
(16).
Page 39
17
17. Now attach the two short frames to the frame with the large gear
wheels. The medium gear wheel on the inner right has to mesh with
the small gear wheel shown below it.
19 20
19. To complete the front of your truck, attach a small gear wheel (8)
and a tire (15) to each end of the front axle.
18
18. Now connect the two axle shafts with a small sprocket wheel (9) to
form one long axle. Turn the axle to make sure that all the gears move
smoothly.
20. Now you will connect the front section to the cargo bed. Then
attach two short rods (4) vertically to the front of the upper side
frames.
21 22
21. At the front, the truck still has to get its movable front section. It
is constructed from two short rods (4), one short frame (3), and two
anchor pins (26).
23 24
23. Now you just need the solar module (23) with holder (22) and
cables (20/21). When you mount it, be careful not to push down on the
cargo bed.
22. Attach this structure to the forward area of the two side sections
with two anchor pins (26). When you attach it, you will have to push
the two rods apart a little.
24. Finally, turn the model upside down again. Adjust the wheels and
tires so that they form straight lines.
37
Page 40
Large Drawbridge
Parts List
2 x base plates 1 4 x long frames 2
4 x short frames 3 8 x short rods 4
4 x long rods 5 4 x large gear wheels 6
4 x medium gear wheels 7 9 x small gear wheels 8
3 x small sprockets 9 1 x medium sprocket 10
2 x large sprockets 11 1 x medium pulley wheel 13
5 x long axle shafts 16 2 x medium axle shafts 17
1 x short axle shaft 18 1 x engine shaft 19
1 x black cable 20 1 x red cable 21
1 x battery holder 22 1 x solar module 23
1 x solar engine 24 4 x shaft plugs 25
20 x anchor pins 26 90 x chain links 29
1 x attachment plate 27
1 x crane hook with spool and cord 28
Tall Bridge with Roadway
Drawbridges aren’t just something found on medieval
castles — they are still used today for roads that go
over rivers and canals. When a large ship comes, the
roadway can be raised up to let the ship pass through.
Then, the bridge is lowered again so pedestrians and
vehicles can cross over the river.
For our next project, we will be building this kind of
drawbridge. The actual bridge is located at the front,
and it can be raised and lowered with the help of
the crane hook, spool, and cord. The cable is guided
over a pulley wheel mounted high up the bridge. The
bridge is just as wide as the roadway running through
the lift machinery structure. This lift structure is built
high in order to allow tall vehicles to use the road as
well. The framework at the rear is needed to let you
anchor the lift machinery securely to the base plate.
The engine turns the cord pulley by way of a combination chain and gear drive.
The direction of the solar engine’s rotation determines whether the bridge is raised or lowered. The
simplest way to change the direction of flow of the
current is to reverse the position of the solar module
in the holder.
When operating the bridge, be careful not to let the
cord jiggle up and down too much. You can stop
the bridge anytime by holding your hand over the
solar module. The shadow of your hand will prevent
enough light from getting to the solar cells. But the
engine doesn’t just wind and unwind the cord. At
the front of the model, there is a medium gear wheel
which is rotated by a reverse gear drive when the
bridge is raised or lowered. It signals to ship traffic
that the bridge is in movement. The large gear wheels
at the top don’t turn at all, however. They just serve to
make the model look nicer.
The model is actually easy to build. You first assemble the bridge itself and then you construct the lift
machinery. Make sure that the sprocket wheels that
are linked to each other are positioned in a straight
line. Also, the chains should not sit too tightly or too
loosely. Check periodically to see whether everything
is moving smoothly and easily.
38
Page 41
1 2
1. First you will build the bridge. Push a small gear wheel (8) onto the
short end of a long axle shaft (16). Then push a short rod (4) onto the
axle.
2. The bridge is the width of five short rods (4). Push all the short rods
onto the long axle shaft.
3
3. Then come three small gear wheels (8): One holds the rods in place,
and the others will be needed as a guideway for the crane hook.
5
5. With the help of four anchor pins (26), attach two long rods (5) to the
other base plate. Be careful to mount the rods correctly.
4
4. A short frame (3) with two anchor pins inserted into it goes on a
base plate (1) with an attachment plate (27).
6
6. Now connect the two base plates together. They are held securely to
one another by the attachment plate.
7
7. Now attach the drawbridge to the two rods. You will need a long axle
shaft (16) and a small gear wheel (8). The short end of the shaft is to
the front in the picture.
8
8. Next, mount the solar engine (24) with the engine shaft (19) and a
small sprocket wheel (9) onto the base plate. The shaft fits precisely
into the corner of the frame.
39
Page 42
9
9. To the rear of the frame, attach a short axle shaft (18) with a large
sprocket wheel (11).
11 12
11. Now mount a second short frame (3) at right angles to the upright
short frame.
10
10. Then add a medium axle shaft (17) and two small (9) and one
medium sprocket wheel (10) to the front.
12. Insert a total of ten anchor pins (26) into two long frames (2). Pay
close attention to the holes that the anchor pins go in.
40
13 14
13. Mount the two frames on the two rods on the base plate.
15 16
15. Next, attach a short rod (4) to the rear frame. Then insert two more
anchor pins (26).
14. Directly over the horizontal frame, attach a short rod (4).
16. Now mount another short rod (4) onto the two anchor pins.
Page 43
short end
17
17. Now add a medium (17) and a long axle shaft (16) along with three
small gear wheels (8).
19 20
19. Now, lengthen the structure with two long frames (2).
18
18. The spool with the cord and crane hook goes on the short axle, and
a large sprocket wheel goes on the long one.
20. Insert a long axle shaft (16) with one large (6) and one medium
gear wheel (7) into the frame.
21
21. On the other side, secure the axle shaft with a small gear wheel and
insert two anchor pins (26).
23 24
23. Place a large gear wheel (6) on the other and mount the rod so that
the large gear meshes with the medium one.
22
22. Insert two shaft plugs (25) into a long rod (5) and mount a medium
gear wheel (7) on one shaft plug.
24. Now mount the drive chains. They are composed of 41 and 49
chain links.
41
Page 44
25 26
25. To secure the battery holder, we will now attach a short frame (3) to
the solar engine.
27
27. Now you just have to mount the solar module (23) and attach the
cables (20/21).
26. A long rod (5) goes on the frame and the battery holder (22) goes
on the rod.
42
28 29
28. A long axle shaft (16) with two medium gears (7) holds the medium
pulley wheel (13) that guides the cord.
29. Guide the cord over the medium pulley wheel to the drawbridge
and attach the hook to the long axle shaft.
30 31
30. Insert two shaft plugs (25) into a short frame (3). A large gear wheel
(6) is mounted on each one.
31. Finally, mount the frame on top of the model and check to make
sure everything works properly.
Page 45
“Iron Annie” Airplane
Two Directions of Movement
The “Iron Annie” is one of the most famous passenger planes in the world. In Germany, it was called
the “Tante Ju” — or “Auntie Ju” — with the “Ju” part
of its name being short for German aircraft engineer
Hugo Junkers. It was technically known as the “Ju
52/3m,” but it got its affectionate nickname because
of its reliability.
Iron Annie was the inspiration for this model. In this
design, the solar engine moves the wheels as well as
the propeller in the center. So there are different directions of movement: while the wheels move forward
or backward, the propeller moves at right angles to
them. This is made possible by a gear drive that redirects the movement.
Parts List
6 x long frames 2 4 x short frames 3
3 x short rods 4 6 x long rods 5
3 x large gear wheels 6 4 x medium gear wheels 7
4 x small gear wheels 8 1 x small sprocket 9
1 x medium sprocket 10 2 x tire wheels 15
2 x long axle shafts 16 1 x medium axle shaft 17
1 x engine shaft 19 1 x black cable 20
1 x red cable 21 1 x battery holder 22
1 x solar module 23 1 x solar engine 24
5 x shaft plugs 25 26 x anchor pins 26
57 x chain links 29
2 x attachment plates 27
On your airplane, the motor doesn’t just turn the propeller up front, it also turns the front wheels. If you switch the direction of current flow, not only
does the airplane move backwards, its propeller turns the opposite direction too.
43
Page 46
1 2
1. First build the two side pieces by combining four long frames (2) into
two large side sections.
3 4
3. Now attach the four rods with the anchor pins to the two double
frames, as shown in the picture.
2. To strengthen the double frames, insert eight anchor pins (26) into
four long rods (5).
4. Next, mount the engine (24) with engine shaft (19) and small
sprocket wheel (9) onto one double frame.
44
5
5. On the other side of the same double frame, attach a long axle shaft
(16) with a medium gear wheel (7).
6
6. The long axle shaft will serve as the front axle. Next, mount two tires
(15) onto the axle shaft.
Page 47
7
7. Now attach the two double frames together. The engine’s anchor pins will help to secure it. Make sure that the two frames sit exactly across from
each other and that the front axle sits in the right hole in the new fame.
8
8. For the drive transmission, place a medium sprocket wheel (10) on
the outside of the front axle.
10 11
10. The power is conveyed to the propeller by a large gear wheel (6).
Secure the gear wheel with a shaft plug (25).
9
9. For looks, your airplane gets two anchor pins (26) and two small
gear wheels (8) with two shaft plugs (25) in front.
11. For the rear axle, insert a long axle shaft (16) into the double frame
and add two medium gear wheels (7).
45
Page 48
12
12. Now assemble the drive chain from 57 chain links (29) and wrap the
chain around the two sprocket wheels.
14 15
14. Mount this double frame on the rear of the plane between the two
long axle shafts.
13
13. To lengthen the tail of the plane, combine two short frames (3) and
insert two anchor pins (26).
15. Attach together two short (3) and two long frames (2) for the wings.
Then insert four more anchor pins (26).
46
16 17
16. Next, insert four anchor pins (26) into two long rods (5).
18 19
18. Two large gear wheels (6) — attached with two shaft plugs (25)
— will make the wings look nicer.
17. Attach the rods to the two double frames. The two attachment
plates (27) will serve as decoration.
19. A medium axle shaft (17), with a medium gear wheel mounted on
its short end, will drive the propeller.
Page 49
20
20. Insert the axle shaft along with a small gear wheel into the center
of a short rod (4) with two anchor pins (26).
21. Attach the rod to the front of the airplane. Adjust tires and gears
and make sure that everything moves easily.
22 23
22. For the propeller, you will need two short rods (4) with four anchor
pins (26) inserted into them.
23. Now mount the two rods on the center drive shaft of the propeller.
21
24 25
24. Now push on a small gar wheel (8). Push the two gars together so
that the propeller is mounted securely.
25. Now attach the first wing. When you mount it, orient yourself by
the holes on the long rod.
26 27
26. Now mount the other wing directly across from the first one on the
tail’s double frame.
27. Finally, mount the holder (22) with the solar module (23) on top of
the double frame and attach the cables (20/21).
47
Page 50
Windmill with Wind Wheels
Power Over Great Distances
This very large model demonstrates how a chain
drive can be used to bridge great distances between
sprocket wheels. In this case, there are three chains
moving three wind wheels. The construction is by no
means simple, and it requires precise work.
The solar engine sits down below on the foundation,
which is made out of two base plates. At the back are
two large frames attached together. In each of these
frames, there is a small wind wheel. The first chain
drive turns the lower wheel. On the axle that turns
this wind wheel is another sprocket wheel, which
drives the other small wind wheel mounted above.
From that second small wind wheel, the power is
further transferred to a larger wind wheel mounted
higher on the front side.
So the large wind wheel is the one that is farthest
away from the solar engine. If you wanted to drive it
directly — without the axles in between, on the small
wind wheels — you would have to use a very long
chain indeed. But long chains can easily slip, and they
are not very sturdy. The little wind wheels have a technical purpose: They let you use shorter chains, and
thus help to ensure a more dependable operation.
Parts List
2 x base plates 1 6 x long frames 2
6 x short frames 3 6 x short rods 4
4 x large gear wheels 6 4 x medium gear wheels 7
10 x small gear wheels 8 3 x small sprockets 9
3 x medium sprockets 10 1 x large sprocket 11
3 x long axle shafts 16 4 x short axle shafts 18
1 x engine shaft 19 1 x black cable 20
1 x red cable 21 1 x battery holder 22
1 x solar module 23 1 x solar engine 24
20 x anchor pins 26 147 x chain links 29
2 x attachment plates 27
48
The solar engine drives not only the large windmill wheel in front, but
also two small mill wheels on the rear side of the model.
1
1. Connect two base plates (1) with the help of the attachment plates
(27). Attach the engine (24) with engine shaft (19) and small sprocket
wheel (9) to the base plates.
Page 51
49
Page 52
2 3
2. Now mount two short frames (3) to the base plate. They will serve as
a support structure for the two small wind wheels.
4
4. Insert two anchor pins (26) into two short rods (4), to the left and
right of the center hole. Mount one rod on the axle shaft with the
anchor pins sticking out to the front, and mount the other rod with the
anchor pins the other way around.
3. A long axle shaft (16) with small (9) and large sprocket wheel (11)
and small (8) and medium gear wheel (7) goes through the second hole
of each of the frame stands.
50
5
5. A second medium gear wheel (7) goes on the outside. The rods form
a small wind wheel held by the two medium gear wheels.
6
6. Now mount two long frames (2) on the short frames and insert a
long axle shaft (16) with a medium sprocket wheel (10) on top.
Page 53
7
7. This is where the drive for the second small wind wheel will be. You
will need a small sprocket wheel (9) as well as a small (8) and medium
(7) gear wheel.
9
9. Now it’s time to build the support structure for the large wind
wheel. First, attach two more long frames (2) to the base plates.
10 11
10. Lengthen the support structure with two long frames (2). Then
mount the holder (22) with solar module (23) on the base plate below,
and hook up the cables (20/21).
8
8. Construct another small wind wheel with two short rods (4) and four
anchor pins (26), and secure it to the axle with a medium gear wheel
(7).
11. Up top, through the center hole of the two frames, insert a long
axle shaft (16) with two small gear wheels (8), plus a medium sprocket
wheel (10) on the outside.
51
Page 54
12
12. Prepare the assembly for the large windmill wheel by first building four identical blades. Build each of them out of one short frame (3), one short
axle shaft (18), one small (8) and one large gear wheel (6), as well as one anchor pin. To connect the blades to one another, you will need two short
rods (4), each with four anchor pins (26).
52
13
13. The wind wheel is composed of two pairs of blades, with each pair consisting of two single blades connected together. The lower double blade
is already assembled, and you can see how the rod is supposed to connect the two blades of the other double blade. In the center, four anchor pins
mesh in such a way as to loosely connect the two double blades to each other. The entire wind wheel is mounted through the hole in the middle.
Page 55
possible additional
sprocket wheel
14
14. The two double blades are attached to the already-mounted axle shaft. Set them against the two gear wheels that are already there. Then add
two more small gear wheels (8), so the blades are clamped between the gear wheels. On the outside, a medium sprocket wheel (10) completes the
assembly. Depending on how precisely you assembled the pieces, you may also need a small sprocket wheel (9).
15 16
15. This picture shows you from the other side how the blades are
attached. The double blades have to sit firmly between the gears so
they don’t slip.
16. Finally, attach the drive chains. They are made of 39, 62, and 46
chain links (29), as shown in the picture on page 49.
53
Page 56
Mobile Crane Car
Removable Crane Assembly
This crane car is actually made out of two separate
models: the crane assembly and the vehicle mount.
That lets you transport the crane wherever it may be
needed.
You dismount the crane assembly on site, so that it
can sit securely while lifting loads. Once you have
lifted them, you remount the assembly onto the car
so that you can carry the cargo to another location.
The heart of the heavy crane car is the actual crane assembly, which can lift and lower a variety of loads with
the help of the solar-driven engine and a crane hook
that is raised and lowered by the cord and spool.
A large pulley wheel mounted on its own framework
serves as a guide for the cord. This framework has
two functions. First, its height makes it possible to lift
large items (for example, a long rod). Without the tall
framework, the distance between pulley and crane
hook would be too small, and many items couldn’t be
lifted properly off the ground.
54
The crane car consists of two separated models: the crane assembly
and the chassis it sits on.
The crane hook extends far enough over the front of crane so that it
can raise loads without interference.
The chassis serves to transport the crane assembly to where it is
needed.
Page 57
The frame structure also makes it possible to lift
loads without banging them against the car or the
gear wheels. If the long rods holding the cord pulley
were to sit directly on the short frame in front, the
hook would always be hitting the assembly.
The drive machinery is held by four short frames. A
large frame mounted on one side serves to hold the
other frames steady. The technical way to say it is that
the large frame “reinforces” the construction. The
short rod holding the solar unit in the rear, as well
as the two cross-rods on the front framework, also
contribute significantly to the reinforcement of the
drive mount framework, and therefore to the crane assembly as a whole.
Parts List
1 x base plate 1 3 x long frames 2
6 x short frames 3 7 x short rods 4
2 x long rods 5 3 x medium gear wheels 7
9 x small gear wheels 8 3 x small sprockets 9
1 x large sprocket 11 1 x large pulley wheel 12
4 x tire wheels 15 4 x long axle shafts 16
2 x medium axle shafts 17 1 x short axle shaft 18
1 x engine shaft 19 1 x black cable 20
1 x red cable 21 1 x battery holder 22
1 x solar module 23 1 x solar engine 24
4 x shaft plugs 25 26 x anchor pins 26
42 x chain links 29 1 x anchor pin lever 30
1 x crane hook with spool and cord 28
1 2
1. A base plate (1) with two anchor pins (26) serves as a foundation for
the crane.
3 4
3. Now add a short rod (4) and the solar engine (24) with engine shaft
(19) and a large sprocket wheel (11).
2. Mount a short rod (4) on the anchor pins, and insert two more
anchor pins (26) into the rod.
4. The next step is to add two short frames (3) with three anchor pins
(26).
55
Page 58
5
5. On the other side of the base plate, mount another two short frames
(3) with three anchor pins (26) on top and four on the side.
6
6. A long axle shaft (16) with small gear wheel (8) and small sprocket
wheel (9) goes through the fourth hole from the top in the frames that
have just one anchor pin on the top.
8
8. Insert a small axle shaft (18). Attach a medium gear wheel (7) to one
side, and the spool with cord and hook (28) to the other.
56
7
7. Now adjust the two sprocket wheels so that they are aligned and
attach a chain made out of 42 chain links (29).
9
9. For the front framework, you will need to mount two short rods (4)
onto the anchor pins on the top of the front frames. Also mount a short
rod (4) on the rear frames.
Page 59
10 11
10. Mount a long frame (2) on the four free anchor pins on the side
away from the engine. This serves to stabilize the construction.
11. The large pulley wheel (12) is held by two short (4) and two long
rods (5) with four anchor pins (26), along with a long axle shaft (16)
with two small gear wheels (8).
12 13
12. Now mount the already-assembled framework to the front of the
crane assembly. Adjust the pulley wheel so it is aligned with the cord
spool.
13. Finally, guide the cord over the pulley wheel, mount the holder (22)
with the module (23) and attach the cables (20/21). Be sure that the
cables don’t interfere with the cord.
57
Page 60
14 15
14. The framework for the vehicle mount is made of two short (3) and
two long frames (2). You will need four anchor pins (26) in order to
combine the frames into a rectangle.
16 17
16. The four anchor pins on the inside serve to support the base plate
of the crane assembly. Use the anchor pin lever (30) to adjust them so
they sit horizontally.
15. Once the frames are connected, attach four anchor pins (26) on
the inside and four shaft plugs (25), which are going to hold decorative
wheels, on the outside.
17. Each of the vehicle mount’s axles is built out of one medium (17)
and one long axle shaft (16). Two small (8) and two medium gear
wheels (7) serve as headlights.
58
18 19
18. The axles are connected by two small sprocket wheels (9). Put four
small gear wheels (8) on the outer ends of the axles so that the axles
do not shift.
19. Now you just have to attach the four tires (15). Test the axles
to make sure they turn easily. Then you can simply place the crane
assembly on the vehicle mount.
Page 61
Heavy Duty Construction Crane
“Crooked” Construction
For our final project, we will build a heavy construction crane. The unusual thing about it is that the
frame sections are assembled a little crookedly, rather
than at a right angle. This is made possible by anchor
pins arranged so that they are offset from one another, with large and small frames mounted on these
anchor pins.
This crane is a very large model. That makes it all the
more crucial that you assemble everything carefully
and that you make sure that everything is attached
securely. Wheels, pulleys, and chains have to turn
easily. The chains are very long, so be sure that their
sprocket wheels are precisely aligned. Otherwise, they
will get twisted. The crane spool and the pulleys have
to guide the cord reliably, so adjust all the wheels and
pulleys carefully.
Parts List
2 x base plate 1 6 x long frames 2
6 x short frames 3 5 x short rods 4
6 x long rods 5 1 x large gear wheel 6
1 x medium gear wheel 7 8 x small gear wheels 8
2 x small sprockets 9 3 x medium sprockets 10
1 x large sprocket 11 1 x medium pulley wheel 13
1 x small pulley wheel 14 4 x tire wheels 15
4 x long axle shafts 16 1 x medium axle shaft 17
3 x short axle shafts 18 1 x engine shaft 19
1 x black cable 20 1 x red cable 21
1 x battery holder 22 1 x solar module 23
1 x solar engine 24 2 x shaft plugs 25
26 x anchor pins 26 142 x chain links 29
1 x crane hook with spool and cord 28
The arm of this heavy construction crane is mounted at a slight angle. The hook is all the way at the front of the model, while the engine is all the
way down on the base plate, with the drive train passing through two very long chains. That is how the great distance is bridged from one end to the
other.
59
Page 62
When you assemble the crane, it is crucial that the drive wheels are
precisely mounted and the chain and gear drives work perfectly.
2
2. Insert four anchor pins (26) into one short rod (4) and attach the
rod to the left base plate. Look at the picture to see where to put the
anchor pins.
3
3. Attach one more short rod (4) to the rod you just mounted. Insert
two anchor pins (26) into this one as well.
60
1
1. Connect the base plates (1) with two long (5) and one short rod (4)
along with six anchor pins (26). Then attach one short (3) and one long
frame (2) to the plates.
4
4. Now, a long rod (5) goes on the two short rods. The permanent pin
on the end of this rod goes into the short frame on the left.
Page 63
5 6
5. The solar engine (24) with engine shaft (19) and small sprocket
wheel (9) sits at the lower end of a long frame (2).
6. Now mount the frame with the engine on the base plate. Four
anchor pins (26) go into the two long frames sticking up vertically.
7
7. Now, attach two long frames (2) to the anchor pins. Attach a short
frame (3) to the bottom of each of them, and connect the short frames
at the rear with a short rod (4).
9
9. In the long frames, insert two long axle shafts (16) with two small
gear wheels (8), a medium (10) and a large sprocket wheel (11), and a
large gear wheel (6).
8
8. For looks, attach two medium sprocket wheels (10) with two short
axle shafts (18) along with a long axle shaft (16) with four tires (15) and
a small gear wheel (8).
10
10. Adjust the wheels so the large gear wheel meshes with the
small one. The two sprocket wheels shouldn’t sit too close to other
components. Check to see if the wheels turn well.
61
Page 64
11
11. For extra decoration, take two long rods (5) and attach a shaft plug
(25) and small gear wheel (8) to the end of each.
13 12
13. Now mount the two long decorative poles on the outer frames.
Check that all the parts sit tightly and don’t wobble.
12. Mount the holder (22) with the solar module (23) on the rear small
frame. Then attach the cables (20/21) so that they don’t interfere with
the drive machinery.
62
14 15
14. Build the first side section of the arm. Connect two short frames (3)
and one long frame (2) with two anchor pins (26). Then attach three
more anchor pins (26).
15. Mount the crane spool on a medium axle shaft (17) with a small
gear wheel (8) and a small sprocket wheel (9). A medium gear wheel (7)
secures the shaft.
Page 65
16 17
16. Now you’ll need a short (3) and a long frame (2), a short rod (4),
a long axle shaft (16), two small gear wheels (8), a small pulley wheel
(14), and five anchor pins (26).
18 19
18. In order to be able to run the cable even higher, mount the medium
pulley wheel (13) on a long rod (5) with a short axle shaft (18).
17. Now combine the two sections of the arm. Adjust the position of
the small pulley wheel so that it is aligned with the crane spool.
19. Attach this rod to the arm and guide the cord over both pulley
wheels. Make sure that the top and forward axles turn easily.
20 21
20. Now mount the arm onto the crane. The arm is positioned at an
angle with the help of the offset anchor pins.
21. Finally, mount chains made of 74 and 68 links (29). For the model
to work well, all the chains and wheels have to move easily.
63
Page 66
Designing Your Own Solar Models
Multiple Possibilities
If you have built all the models in this book, you are
a real solar engineer. You know lots of ways the solar
engine can be used and you have learned the function
of all the components in the kit.
But the models that you have built are by no means
all the things you can make with the solar engine and
the other components. You could also, for example,
build a tall crane, a fan, or a spaceship. Let your
imagination run free and invent your own models. In
all cases, the important things are that the construction is stable and the drive systems run smoothly.
Stable Construction
Above all, be sure that your models have a stable
construction. Nothing is more frustrating than when
a model falls apart as soon as you try to use it. That is
particularly true for large models. Be sure to stabilize
the building components sufficiently (see p. 55). For
models that are not mobile, it is always a good idea
to use a base plate as a foundation. It gives the model
stability. When assembling a model, it goes without
saying that you should never try to jam components
together by force or bend them. If two pieces aren’t
connecting or inserting easily, then you’ve constructed something wrong. You can always find a different
way to do it.
Smooth-running
Drive Systems
With all drive systems, it is important that they run
smoothly. Chains must be neither too loose nor too
tight. The sprockets holding a chain should be lined
up exactly. Otherwise, the chain will easily twist and
your model won’t work well.
You can design and build an almost endless number of solar vehicles
and devices, such as this tower crane.
The same goes for gear drives: the gear wheels have
to mesh with the right distance between them. Only
then will everything work well and utilize the solar
engine’s full power.
Once you have finished constructing your drive system, before building anything else you should check
to make sure that everything runs well. Hold the
engine up to the light and make sure that some construction detail or other isn’t placing too heavy a load
on it. That can happen, for example, with a car design
that has ended up carrying too much weight.
Drivable models run well when they drive on four tires
(15) or on a caterpillar track (see p. 24). Gear and
sprocket wheels don’t work well as driving wheels,
because the solar engine would have to expend too
much force to move them over the ground.
That’s it! Have fun constructing and building!
64
Page 67
US Annual Average Solar Energy
received by a photovoltaic cell
Source: Electric & Hydrogen Technologies & Systems Center,
National Renewable Energy Lab, May 2004
Page 68
Loading...