I build close to fifthy boomerangs over more than 20 years, till I got
able to carve my first really
perfect boomerang.
Lots of items return to the thrower when they are
tossed in the air. A stone thrown upwards falls back, a frisbee
thrown high upwards in the wind, commercial boomerangs that return once
in a while by mistake... To me a real boomerang is something
you throw like a hatchet. It makes a long and complicated flight that
seems to
last an eternity. It rises in the air, changes direction, changes
again... Several times you get convinced it will never return. Then
it changes again direction. It passes behind you. It halts in the
air, still rotating. Then it gently descends towards you, like a
plane or a helicopter landing, rotating horizontally. You just have to
extend your arms to catch it. The
flight of a real boomerang is a mystical journey.
My
best criterion to distinguish my favorite kind of boomerang is you have
to throw
it holding it vertically like
a hatchet
or nearly. At most at 10°
to the right from the vertical. You throw it towards the horizon, with
a pinch to make it rotate (just like a hatchet).
Other kinds of boomerangs exist. One kind flies a neat
circular path and is thrown at an angle around 30° up to 60°
from the vertical. That's the kind used in boomerang jugglery. Yet
another kind is thrown nearly flat, up to 90° from the
vertical. It makes a chandelle then returns at fast speed towards
the thrower (very impressive, hard to catch and sometimes painful).
That's the kind
used for long distance
boomerangs.
Some answers to common questions:
One cannot say that you stretch your arm and the boomerang comes
back in your open hand. A boomerang has no brains neither eyes. It
doesn't aim at your hand. Rather, a good boomerang is such a precise
device that it comes back so close to the launcher that he just has to
stretch his arms to catch the boomerang. A lot of good boomerangs need
to be tuned a little bit. Once they are correctly tuned for the day,
they will come back neatly everytime. Boomerangs designed to fly far
away will get back less close to the launcher than boomerangs designed
to fly a short path.
Some boomerangs require a lot of force and skill to be launched
correctly. You need a lot of training and you need to throw them by
rotating all your body, like a hammer thrower. But a good common
boomerang requires neither of these. You only need a little training. I
once invited a friend to launch boomerangs. He never even saw a
boomerang fly before. The only sport I knew him doing is bowling. To
begin I proposed him to launch a boomerang I considered not very good.
I didn't want him to launch my best boomerang without first acquiring
some experience. His first few trials were bad throws and I explained
him his errors. On maybe his fifth trial he made all movements correct
yet with not enough force. The boomerang had just left his hand that I
told him: "right, well done! You just need to put more force in it." It
was obvious to me that the boomerang would land exhausted a few tens of
meters further. Instead it made a beautiful flight and landed neatly,
quite close to my friend. It was the most beautiful flight I ever saw
that boomerang perform. That day I learned that silly boomerang was in
fact a good one. It just has to be thrown very gently, like by a lady.
I had to train till I got able to weak my force down enough to launch
it correctly... The same way, I bought a little boomerang made for
children. I never managed to throw it correctly. But women and children
did, after just a few tens of minutes training. I suppose this is due
to the fact such little boomerangs need a high rotation speed. My
strong manly hand just isn't capable to do that, while a child's or a
women's wrist can.
The distance a boomerang flies and the path it follows depends on
the boomerang itself, not the force you throw it. You need to give a
boomerang enough speed to allow it to fly its entire path but more
speed is useless. The minimum force you need to deploy depends on the
boomerang. More force will change the flight path shape and make the
boomerang fly a little further but the differences won't be tremendous.
Throwing lightweight boomerangs really hard can be fun because they
will rise quite high in the air. But they won't come back correctly.
You don't need to understand the whole content of texts like this
one to get able to carve and launch boomerangs. Just find pages on the
Web or books in stores that explain how to carve a boomerang. Buy a
neatly flat and thin board of quality plywood. Use whatever tools
available to cut the boomerang shape out of it. Use a wood file to
carve the rough wing profiles. Use coarse sandpaper to round it and
fine sandpaper to smooth it. (Wrap the coarse sandpaper around a thick
flat rectangle of wood to get neat and continuous profiles.) You can do
this even if you never worked on wood. You will just need more than one
board of plywood, to train, and maybe some adhesive plaster. Maybe put
some adhesive plaster on your fingers before you get hurt (no kidding,
you will quickly see by yourself which parts of your hands are
endangered). The only important advice for a beginner would be to ask
an experienced person for tools that cannot harm the fingers too much,
or for a basic training to how the tools can be used safely. I never
heard of a boomsmith loosing a finger, anyway a misused sharp knife or
an electric saw can do bad things. You don't need such tools to make a
good boomerang. Your first boomerang very probably will come back "very
roughly" towards the thrower. You may need to launch it hundreds of
times till you get able to more or less understand what you're doing.
Your first boomerang will be like most of the ones sold in stores: very
approximate and a little deceptive. It will be really good only for
children who love to go running after the boomerang while it lands
anywhere far away. What matters is you will get convinced your hands
can get something out of wood and a boomerangs at least tends to fly
back to the thrower. Get back to texts like this one to learn the
details.
A boomerang is not meant to hit something during the flight. If
it does, it won't come back to the launcher. Another kind of "wood" is
used to hit animals or enemies: the killing stick. A killing stick is
commonly ten times heavier than a boomerang and it has a much wider
angle at the elbow than a boomerang; much closer to 180°. A killing
stick flies straight, rotating flat above the ground. It doesn't come
back (one of the killing sticks found in the tomb of Tutankamon comes
back if you throw it at a strong upward angle towards the sky). It is
less deadly than a spear but it has an advantage upon a spear: a spear
falls out of the sky like a stone, hence it has few chance to hit
something if you launch it towards a loose group of little animals far
away. A killing stick flies at constant altitude close to the ground,
hence it has more
chance to hit something when it traverses the group of animals.
Boomerangs are sometimes used for hunting anyway. I was told they are
launched
inside swarms of little birds. While hovering in the swarm they knock
down some of them. I don't know if I can believe this because to
me little birds are far too fast and agile to get hit by a boomerang.
Maybe bigger birds... I have more confidence in another
explanation: aborigines spread nets between trees, then they launch
boomerangs above the birds. Instinctively the birds believe the
boomerangs are birds of prey, they dive towards the ground and get
caught inside the nets. There are many other reasons why
aborigines use boomerangs: gaming, training, prestige, music,
religion...
Their symbolic approach of the shape of the boomerang is quite close to
that of the Christian cross: the expression of the link between past,
present and future.
Below is a 50 DPI scan image of my final boomerang. The wing chord is
40 mm
and the thickness is a little less than 4 mm. The leading wing is the
vertical one in the picture. The trailing wing is the horizontal one.
When throwing I hold the boomerang in my right hand, by the end of the
leading wing. The trailing wing points in the direction I throw. It's
really just like throwing a hatchet. If thrown,
the boomerang displayed below would turn counterclockwise and travel
towards the
left of the page. Click on the picture to get a 300
DPI scan (1 MB
size):
The boomerang displayed above is rather dirty because it endured
several days
of experiments. I
don't varnish my boomerangs because that makes the wood feel dead.
Besides the
polyurethane varnish I have makes the
wood more fragile to local impacts.
You can see on the picture I glued two copper coins inside the
wing ends. This is because while I tried out and modified the
boomerang, the elbow got heavier and the ends got lighter. So I
compensated by hollowing the ends, insert those two coins and glue them
tight with epoxy glue. They are very lightweight so my boomerang cannot
be called a "weighted" boomerang I think.
You need no special skills
nor force to launch it. Just a little
training. It doesn't fly very fast and it doesn't rotate at
high speed. It is not much
sensible to the wind during the flight. It won't make much damage if it
hits somebody (some pain
anyway, maybe even broken spectacles).
Let's
first talk about what doesn't matter much.
The shape
As
you can see there is nothing special with the shape. The angle
between the wings is almost exactly 90°. For my next boomerang I choose
a
little more than
90°, because at 90° a boomerangs looks like a halve
painting framework.
The
boomerang elbow is part of a circle. The center of this circle is
roughly situated at the center of gravity of the boomerang. I choose
this so the elbow won't brake the rotation of the boomerang. I
believe this is not very important, anyway I like the principle of it.
The picture below shows the boomerang, its center of gravity and
three circles. I wrote a little computer software to design the
boomerang to get the center of gravity at the right place. Once the
boomerang was built I used the standard method you learn at school to
verify the center of gravity: hold the boomerang vertically by an end
and let it rotate towards the ground, use a plumbline, draw the
verticals on a paper taped to the boomerang (the white disc behind),
intersect the
verticals...
The
three cyan, yellow and magenta circles are important. The inner cyan
circle determines the range of the
boomerang. I'd rather say the ratio between the external magenta circle
and the inner cyan circle. The closer the cyan inner circle is to the
outer magenta circle, the farther the boomerang flies. Little
boomerangs with a cyan inner circle close to the outer magenta circle,
fly very far away. While large boomerangs but with a comparatively
little inner cyan circle, may fly less than twenty meters away. The
middle yellow circle shows where the wings begin (and
the
main aerodynamic lift forces) (red little circles).
The
wing ends are simply rounded. This is not mandatory. I made good
boomerangs with square ends (just two rectangles of wood glued
together). Anyway rounded ends are best, for several reasons:
It's
an aerodynamically efficient shape. Not the best one but a good one.
It's
the best shape to hold and launch the boomerang.
It's
the most rugged shape to withstand impacts.
It's
the least dangerous shape should the boomerang hit something or
somebody.
Wing profile
The
wing profile is roughly this, then rounded. The trailing edge is left,
the leading edge is right.
The
profile in the middle of the elbow is roughly this; two janus leading
edges:
All
other profiles are smooth transitions between these two profiles.
Also the shape on the rounded ends is a smooth transition between the
leading edge and the trailing edge. I make sure there are no
irregularities and the wood is polished with very fine sandpaper.
I carve the rough shape of the profile with an Opinel knife. Then I use
very coarse sandpaper (grain 40) to get a precise squary shape. Then I
round that shape out with softer sandpaper (grain 200). Then I polish
it with even softer sandpaper (grain 600). I end with the smoothest
sandpaper available (grain 1200). Don't use low-cost sandpaper for
wood. Use high quality expensive sandpaper, for example the kind that
can be made wet (but don't wet it).
The
profiles don't matter much. I never got significant enhancements by
changing a boomerang profiles. Differences in the profiles do change
the boomerang behavior if they modify the wing incidence or create
turbulences. Yet the profiles themselves change nothing. So just carve
out a good profile, adequate for slow speeds, and everything will be
fine. If you need to change the incidence or create turbulences,
maybe better twist the wings or use dedicated turbulators. Your choice.
In
order to carve good profiles you must understand a few facts:
A
very important parameter for wings flying at low speed is their
thickness. Look at the wings of the first airplanes or at ventilator
blades. They are all quite thin. Don't exceed a thickness of 1/10 the
wing chord. 1/10 is already very thick.
This
is roughly the best shape for a wing profile. The leading edge on the
right is drawn quite steep. This is adequate for model gliders flying
at very low speeds and strong angles of attack. It is a bit overdone
for a boomerang I think:
Wide
curve at the trailing edge, steep curve at the leading edge. The
drawing above shows an infinitely thin wing (which is best for slow
speeds). A real wing profile is
such an ideal curve yet with matter around. To find the curve inside
a wing profile you draw circles to find its middle line. (While drawing
the picture below I realized the cuts I drew above for my boomerang
profile are not the most adequate.)
As
you can see the profile I use very roughly matches the ideal curve. I
experienced no need for a better match.
The material
A
good boomerang needs to be both quite flat and very rigid. You can
use whatever material to carve a boomerang out of it provided it
matches these two conditions.
You
may be intrigued why I glued two branches together although my
boomerang is carved out of a thin plywood plate (Polish multipine). The
reason is when you bend that plywood in one direction it is very
rigid, yet in the other direction it bends a little. I
couldn't afford for aeronautic quality plywood.
So I cut the two
wings in the same rigid direction then glued them together with
Araldite epoxy glue. (My advice: heat the boomerang while the glue
hardens. At 60 C° the glue becomes ways stronger.)
The
heavier the material, the better, though I'm not sure if a density of
much more than 1 would yield a good result. A density of 0.5 seems
poor to me. My actual boomerang has 0.8. My next boomerang, in oak
wood, will have a little more than 1.
Now
let's talk about the three key parameters: turbulators, wings twist
and wings dihedral.
The turbulators
The
turbulators are
situated on the upper side of the leading edges of the wings. They are
those gummy flat knobs on the wings middle part and the carvings on the
wings ends. The carvings are displayed on the right
of the picture below. They aren't much
visible and quite narrow, anyway they are mandatory:
This is a schematic drawing of these two kinds of turbulators. Please
note I do not pretend the positions and sizes of these turbulators are
the best ones. I
simply don't know:
When a wing passes trough the air at a
high speed,
the
air follows a neat and reliable path around the wing (the less chord,
the more speed needed, due to the Reynolds number).
The problem
with a boomerang wing is it travels at quite a slow speed through the
air (especially the parts on the second (yellow) circle). When a wing
travels
too slowly through the air it doesn't lift at all, because the way
the air passes around the wing engenders no lift.
Around boomerang
wings, the behavior of the air can be very unpredictable. You may have
the ends lifting yet not the middle part. Or one wing lifting and not
the other. It is completely unstable, oscillating, erratic... In one
word: unpredictable. You throw a little different way, little gusts of
wind occur during the flight, a little bit of dirt on a wing... any of
these can cause strong
differences on which parts of the boomerang lift. Hence the
flight path of the boomerang changes.
The remedy are the turbulators.
They engender little turbulences at the upside of the leading edge of
the wings.
These turbulences force the air to follow the shape of the wing,
hence to lift. That's what makes a boomerang reliable like a Swiss
clock. Many different kinds of turbulators exist. I didn't experiment
much with them. I'm satisfied with the solution I found: little
polyurethane flat domes for the middle parts of the wings and carvings
for
the wing ends. The effect of these turbulators is miraculous. They
can make an excellent boomerang out of a mere piece of wood.
Turbulators allow to use thicker wing profiles.
I suppose ethnic
drawings and carvings on genuine Aboriginal boomerangs act
as turbulators.
These are three other common kinds of turbulators used on boomerangs. A
steep angle on the upper side, holes through the wings and an angular
shape:
I never tried to heavily weight a boomerang. Anyway this is reputed to
better a boomerang. One reason may be the places where the weights are
inserted become turbulators. Let's be serious, a good boomsmith
smooths out
the surface so the boomerang gets the exact some shape as before it was
weighted. I think that if you weight a boomerang while keeping its
center of gravity at the same place, there is at least one good reason
this betters the flight: a heavier boomerang needs to be thrown
harder and rotates faster. Hence the aerodynamic behavior of the air
around the boomerang becomes more reliable. This is just a matter of
personal choice but I don't like the idea of weighting a boomerang.
First because I prefer slow and beautiful flights. Second because this
makes the boomerang both more fragile and more dangerous.
Wing incidence
Second
key is the respective incidence of the wings.
The leading wing must
lift more than the trailing wing. It may even be that the trailing
wing actually forces downwards instead of lifting! Why this? If you
already studied boomerang theory you heard a boomerang behaves like
a gyroscope. It's
like a rotating disc.
Let's proceed step by step to explain:
Imagine a boomerang is simply rotating. It has not been launched, it is
just immobile in the air yet rotating fast. It acts like a simple
propeller. Say the rotating boomerang forms a vertical disc. It blows
air towards the rear, like a propeller. A lift force pushes the
boomerang frontwards. Where is
the resultant of that lift force located; its average position on the
disc? It is situated right in the
middle of the rotating disc, on the center of gravity of the boomerang.
The picture left shows the rotating vertical disc. The picture right
shows the disc from aside (that's what you see when the boomerang
left your hand). The boomerang is rotating counterclockwise.
The lift force is symbolized by the 3D red arrow. That average
resultant
point
where the aerodynamic forces lift the rotating disc is of key
importance:
Suppose the boomerang wings have no lifting profile. There is no
aerodynamic force (no red arrow). Suppose you throw that boomerang like
a hatchet. It will simply move straight ahead, like a hatchet or a
stone. The picture below is a helicopter view from such a trajectory.
We are high above the ground and look down at the person who will
launch the boomerang. The person throws the boomerang to the North. The
boomerang moves in a straight line, falling to the ground, like a stone
thrown towards an object:
Lets reintroduce the aerodynamic lifting force (the red arrow). The
rotating boomerang is a gyroscope, so its plane of rotation tends to be
stable. In our helicopter view the aerodynamic force (the red arrow)
tends to push the boomerang towards the West. The thrower throws the
boomerang again straight towards the North. Yet the aerodynamic force
makes it drift towards the West:
This flight path is wrong. Because of a key phenomenon we must now
introduce. Look at the picture below, the left one. Suppose the
rotating vertical disc moves towards the
left of the page. When a wing passes in the upper part of the disc, it
will get more wind than when it passes in the lower part of the disc.
Hence the wings experience more lift force in the upper part than in
the lower part. This shifts the aerodynamic resultant average force
upwards. The red arrow moves upwards in our drawing (this is a key to helicopters.):
The average force is now situated above the center of gravity. What
happens in such circumstances? At first thought you would expect the
disc to turn towards the ground:
This is wrong. Indeed the rotating boomerang behaves like a gyroscope.
It turns this way, very slowly:
That's the gyroscopic
precession. What path flies such a boomerang if you launch it like
a
hatchet? It flies the circular
path pictured below. Yet it hits the ground before it can close the
circle and get back to the launcher:
Why does the boomerang hit the ground? Well because there is no upwards
force to keep it in the air. Just like there is no upwards force to
keep a stone in the air. The aerodynamic resultant force and the
gyroscopic precession curve the flight path to the left. But no
component of the force tends to keep the boomerang above the ground.
A first solution to keep the boomerang in the air and
make it fly a full circle, is to launch it with an angle to the
vertical, between 30° and 60° depending on the boomerang. Then a part
of the aerodynamic lift force is directed upward and can keep the
boomerang in the air:
That's the way some jugglery
boomerangs and some toy boomerangs are launched. That's the way you
launch simple triblade boomerangs:
What I want is a boomerang I launch holding it vertically and it comes
back in a near horizontal position. That's the way you get poetic
flights. I want the boomerang to fly a circular path and I
also want it to go lay horizontally. How can this be achieved?
Answer: the resultant lift force must be shifted frontwards. Indeed
that way the boomerang/gyroscope will tend to rotate a way that gets it
horizontal:
How can we shift the resultant lift force forwards? My favorite
solution relies on the fact the two wings don't have their maximum lift
at the same place of the rotating disc. The leading wing has its
maximum lift when it is vertical, which happens when it is forward (to
the
left on the pictures):
While the trailing wing has its maximum lift when vertical and backward
(to the right on the pictures):
So, simply privilege the leading wing lift and decrease the trailing
wing lift. I do this by increasing the leading wing incidence and
decreasing the trailing wing incidence. This needs to be tuned. If the
boomerang doesn't close its flight path and lands left of me, I know I
didn't privilege the leading wing enough. If the boomerang flies a path
in the shape of an alpha letter and lands right of me, I know the
leading wing is too much privileged and has to be decreased:
There exists a curious variant to the alpha shaped path. The
boomerang obviously starts flying an alpha path yet it will bend its
end and get back to the launcher anyway. What happens is the boomerang
gets flying horizontal in the middle of the path (too soon, due to the
leading wing lifting too much). The boomerang continues its slow
rotation (gyroscopic precession) and gets turning vertically again.
That's what bends the end of the path towards the launcher. The
boomerang arrives at the launcher turning nearly vertical and flying
quite fast,
which is a bit hard to catch:
The boomerang pictured below is made out of cambara wood (a €5 slat
bought in a store, cut in three sections, glued together then profiled
with lots of grain 40 sandpaper) (the cut in the middle of the picture
appears because two scanner pictures were pasted together). It makes a
beautiful "bended alpha" flight. It needs to been thrown with a lot of
force, makes its circle far away, slowly flying above trees like a bird
of prey. It seems to have forgotten about me. Then it bends it path,
comes down, accelerates and seems to be searching for me like a
missile.
Other methods exist to privilege the leading wing:
While keeping the center of gravity at the same place, make the
leading wing a little longer than the trailing wing. Being longer, the
trailing wing's end moves faster in the air and gets more lift.
Put a weight inside the trailing wing. That way the center of
gravity moves towards the trailing wing. Hence it will move slower
through the air and the leading wing will move faster:
Bend the wings backwards. This is often used for triblade
boomerangs:
Put the wings closer together. That way the turbulences created by the
leading wing will hamper the trailing wing and decrease its lift:
I change the angle of incidence of the wings by twisting the wood. I
hold
the middle of the wings above a camping gas fire (hence the
little burnings you can see on the big scan). Once the wood is hot it
becomes bendable. Ensure the
inside of the wood is hot too, not only the outside. Be patient and
don't heat too much. Force with your hands and keep the wood bended
while it cools down.
I
recommend you make all parts of the wings exert an aerodynamic force.
Both the middle parts and the ends. I made boomerangs with for
example a trailing wing build to be neutral; exert no lift force. The
result is poor. No matter the aerodynamic force is upwards or
downwards. What matters is there is a force. On my boomerang the
leading wing was twisted about 7° upwards and the trailing wing
7° downwards.
Two
remarks about other kinds of boomerangs:
You
will find recommendations that the wing ends should be directed
towards the rotating center of the boomerang. This is for fast
boomerangs flying a simple circular path, like the yellow
triblade displayed above. They are thrown at a strong
angle between 30° and 60°. If the wing ends are directed
towards the center you cannot tune their respective incidence to tune
the resultant lift point.
Long
distance boomerangs are tuned the opposite way: trailing wing more
lifting than the leading wing. To get this the tricks listed above can
be used yet the opposite way. Those boomerangs are thrown
nearly flat, close to 90°. They fly very fast, make a
chandelle and plunge back at high speed towards the launcher.
Please note the explanation I give why the boomerang goes flying flat
is partially unsatisfactory. It doesn't explain why the boomerangs ends
flying really flat above the ground. Actually I don't know what exactly
happens. Anyway the explanations I give here are all I need to build
and
tune my boomerangs.
The dihedral
Third
key is the dihedral. A
quality boomerang yet with no dihedral tends to
continuously rise in the air and come back down a little loosely, once
the energy is consumed. You have to force the boomerang to stay close
to the ground (yet at a few meters altitude). You do this by
tuning a negative dihedral:
Again,
I bend the wood downwards using a little camping gas fire to heat the
middle zone of the wings. Ideally the bending should be constant over
the whole boomerang length. I just bend the middle of each wings.
You need very little bending. It's almost invisible. It is far overdone
on the picture above. Yet it
changes the quality of the flight dramatically. Again, it becomes
precise and reliable like a Swiss clock.
The
problem with cheap wood is it looses part of its bending after a few
days. That's one more reason my next boomerang will be made out of oak
wood.
Some
authors recommend to carve the above side of the wing tips strongly
downwards:
To
me this is a way to achieve a beginning of a negative dihedral. I
don't use this. First, because this start of a dihedral is not enough.
I
need to bend the wood anyway. Second, because it makes the boomerang
ends more fragile and more dangerous.
I believe some tricks to better a boomerang only tend to brake it in
flight. That way it doesn't fly too high. Its a concurrent method to
the dihedral. I favor the dihedral because it preserves the boomerang
energy and ensures a cleaner flight.
It might be that a downward angle of incidence of the wings avoids the
need for a negative dihedral.
Commercial boomerangs
I bought several boomerangs, from different manufacturers and in
different stores. All except one had boasting commercial arguments:
designed by a world champion, made out of aeronautic plywood or carbon
fiber, beautiful paintings, extensive tutorial, only €1 price... All
are really very bad, they can't be named boomerangs, except the one
with no commercial arguments. It is the model "Sirius" from the
well-known model aviation brand "Günther", pictured below. It really is
a fine and enjoyable boomerang. Its sole default is it has no negative
dihedral. So it rises high in the air and doesn't come back to the
launcher with a lot of precision. Anyway that can be tuned with a
micro-wave oven and a little skill. (Actually, one little commercial
boomerang I thought to be quite bad returns correctly when it is thrown
by a child or a woman. Is suppose this is because it needs a high
rotation speed and for this a little hand is better.)
Wind
As I mentioned in the text, once a boomerang is made the right way it
is no more sensitive to wind turbulences or the like. Anyway if the
wind is really strong you have to compensate for the drift it will
cause on the boomerang flight path. The common advice is to turn
yourself towards the wind then rotate 45° to the right and launch the
boomerang in that direction. My experience is I often have to rotate
60° up to 90° to the right. I believe the 45° to the right is for
boomerangs you launch nearly flat and that make a chandelle.
Also I know the direction of the wind is not the same at the height of
my head than at the flight height of the boomerang. I often went to a
terrain where I could see a wind vane on top of a little tower. There
often was a difference of several tens of degrees, up to 90° between
the wind direction I sensed and the direction shown by the wind vane.
The other thing you have to do when the wind is strong is launch the
boomerang a little more horizontal. Hold it say 15° up to 20° from the
vertical.
When there is wind you have to find the correct angles by
experimenting. Once you are trained you will "feel" the correct angles
quickly.
You may sometimes get the feeling the wind direction is unpredictable.
Again, what you perceive close to the ground is not always reliable.
Sometimes it is better to forget about the wind you perceive and try to
find the correct angles by launching the boomerang. I was able to get a
majority of neat returns in a quite strong and changing wind.
Some tricks
Keep your eyes on a point on the horizon line and throw the boomerang
towards that point. It can be an object nearer than the horizon but it
should be on the same height as the horizon. This allows you body to
better coordinate its movements when launching. When training friends I
sometimes place myself about 20 meters in front of them and propose
they launch the boomerang towards me like if it was a hatchet intended
to hit me.
When you get to a terrain to launch boomerangs, maybe first launch
low-cost plastic boomerangs a few times. This can avoid hurts to your
expensive or self-made valuable boomerangs.
If a boomerang falls in high grass or bushes, look closely in the
direction it fell and memorize that direction and its decor. Then mark
the place where you are (by depositing an object or by using always the
same place). Then only walk straight in the direction the boomerang
fell. If you don't find it, you get a second chance by coming back to
the marked place and get the direction again.
Boomerangs with at least a strip of red/pink fluorescent paint all
around are far easier to find back.
Tend to launch the boomerang always from the same optimal place, even
if this means double the length to walk. If you continuously change
place by launching the boomerang from the place it fell, you increase
the risk to make bad throws, to hit somebody or to loose the boomerang.
Boomerangs were birds in another life. Or they contain the soul of a
bird to be born, I don't know. One thing's for sure: they love to perch
high in a tree. Avoid trees or bring with you a very long fishing rod.
To get back my final boomerang I had to go buy two long wooden rods in
a
nearby store and duct tape them together. At that time it was still
quite badly tuned and I really thought of leaving it in the tree.
Getting back boomerangs perched 7 meters high in a tight mesh of
branches,
is a sub-art of the art of the boomerang. Especially when you forbid
yourself to harm the tree. Obviously the boomerang is responsible for
the situation, not the tree.
If you throw a boomerang towards an object it will never reach that
object because it will change direction and rise in the air.
Nevertheless don't throw a boomerang towards a person, even far away.
Boomerang throwers are cool and reassuring persons. Think of the
boomerangs throwers that will come after you. You should not make the
indigenous population afraid of boomerang throwers.
Keep in mind some open spaces are used by all kind of persons: bikers,
joggers, football players... My experience is they won't come to you
and ask you to let them use the terrain for a while. Instead you have
to
notice them, redraw and let them use the terrain. Only go back throwing
once they are finished and gone.
If you get pain in your arm after a few launches this means the
boomerang is not adequate for you. It is either too light or too heavy.
The principle is the boomerang should leave your hand carrying most of
the energy your muscles developed. If it is either too light or too
heavy, part of that energy will stay in your arm and echo in your
muscles and bones, harming them.
When I go launching boomerangs I cannot expect a boomerang to return
perfectly on the first launch. Sometimes I need a ten or so launches
till the magic builds up. Then the boomerangs seems to love me,
whatever way I launch it. This also means maybe you should not go
launching with all your boomerangs. Often I just take only one good
boomerang (and a plastic boomerang for the first few launches). I focus
on that boomerang and I get far better results than by throwing loosely
all kinds of boomerangs.
I tend to launch all my boomerangs the same way (holding them nearly
vertical) and tune them so they get back neatly. If you are performing
your first trials with a self-made boomerang, most probable is the
boomerang will return far too much to the left of you. If you don't
want
or cannot tune it, simply launch it holding more horizontally. If you
launch it too horizontally, at best it will arrive right of you. At
worst it will smash into the ground, a ten or so meters in front of you.
The content of this text is about boomerangs for right-handed persons.
If you are left-handed, revert the wing profiles (leading edge -
trailing edge). Also you need to turn left from the wind.
Acknowledgments
I wish to thank my friend Pierre Backers who lent me his Dremel
electric saw.
Science and modern technology helped me build a good boomerang but I
would be nowhere if I hadn't spent hours studying photographs of
Australian Aboriginal boomerangs and read through lengthy descriptions.
The current situation of Australian Aborigines is quite good compared
to other minorities in the World. If you would like to do something to
please me take a look at www.survival-international.org
and possibly angryindian.atspace.com
