http://rc-avti.si/
Modelarska Trgovina v MARIBORU
RC modeli višjega kakovostnega razreda po izjemnih cenah,info na mail:mesgrad2@siol.net , 0038641610456,LOVSKA ULICA 56,2000 MARIBOR.We ship to all countries of the European Union.
http://rc-avti.si/sl/Radijsko voden model je model na radijsko (daljinsko) vodenje, ki ga
upravlja modelar s svojo RV napravo. Mislimo, da kakršna koli leteča
zadeva, ki vsebuje svojo "pamet" (tu ne mislimo gyro stabilizacije,
ampak senzorje ki omogočajo avtonomno letenje) katera ji omogoča
samodejno ali predprogramirano avtonomijo letenja, ne spada več pod RV
model.
Vsi osveščeni modelarji letijo na za to dejavnost primernih terenih,
se držijo normalnih in običajnih procedur, ki so se izoblikovale z leti
in se čim bolj izogibajo letenju na način, ki bi ogrožal tretje osebe,
ki niso spoznane z našo dejavnostjo. Mislim, da ni potrebno posebej
poudariti, da nesreče "Zavarovanje za povzročitev škode tretji osebi" ne
prepreči, je pa moralno, da ima vsak modelar, ki leti z modeli, kateri
lahko povzročijo tovrstno škodo, urejeno to zavarovanje.
Vsi leteči modeli, ki letijo nad naseljenimi območji in ostalo
infrastrukturo z namenom FPV letenja, ali zajema video in foto materiala
v komercialne ali lastne namene, ali zgolj za "zabavo" ob sproščanju
adrenalina na nevarnih področjih, bi morali spadati v posebno kategorijo
letečih naprav, popolnoma distancirano od "običajnih" RV modelov. Tako
njihove, niti naše neumnosti ne bodo imele posledic (če pride do
zakonskih ureditev v smislu restrikcij in sankcij) za nedolžno nasprotno
stran.
Ne nas razumet kakor, da ne maramo FPV in neobičajnih letalnih naprav! Nam se vse dopade!
Ena od naših želja je, da boste nekega dne s svojo FPV opremo uživali v
jadranju na pobočju in primernih lokacijah z veliko maketo jadralnega
modela ,helikopterja ali multikopterja, tako počasi ali hitro uživaško,
kot smo v mlajših letih leteli z zmajem. Tako si bomo povrnil tiste
stare občutke in se počutili, kot da imamo spet samo 18 let.
When you’re just starting out and wanting to learn to fly a
quadcopter there are a few general rules you should follow. Remember
you are flying a powerful piece of machinery that can break it self and
can damage other things if a collision happens. Quadcopters do have
somewhat of a learning curve so being patient and really getting down
the flight controls is extremely important to flying well and keeping
your costs to a minimum.
Things to consider:
Safety of yourself
Safety of others
Keeping your quadcopter in one piece (it can be expensive!)
Not breaking anything (windows, cars, etc)
Flying away and losing your quad
With all of the above taken into consideration we recommend the following scenario when first starting out.
Take your quadcopter to a large, wide open field with no buildings or power lines around.
Keep distractions at a minimum(people, phone, etc) and strictly focus on the task at hand.
Some recommend tying your quad down with a 4-5 foot piece of string to limit it from flying away
Start 1-2 feet above the ground and practice hovering, flying from
spot to spot, and landing. Get a really good feel for the controls
Once you are confident in your skills take things to the next level
by flying farther and higher. Don’t push it, as you increase the
distance the technical aspect of things will become more and more
difficult. You will need to learn to adjust and use your judgement on
how fast you want to push the limit.
As always, have fun and enjoy the hell out of your new toy!
Quadcopter Instructional Video
We recommend you watch the following video that covers the majority
of the things we just spoke about along with some additional details and
trouble shooting ideas.
The AR Droneis
very simple to fly but does not fly like anything else on the market.
If you are going to move up to bigger or more advanced quadcopters you
are going to need a different set of flying skills. In this article we
are going to start learning how to fly them and help you get your copter
off the ground.
The first thing you need to know is that flying a quad is exactly like flying a R/C
helicopter. The controls are exactly the same so if you have helicopter
experience, you can easily fly a quad while flying a quad is excellent
practice for flying a helicopter.
The Controls
Unfortunately, if you have been using the AR Drone, you will find the
controls to be basically swapped when you move to a different product.
Normal controls will have the altitude/rotate on the left with the pitch control on the right. If you don’t know what that means, just follow along for a complete explaination.
Altitude On
the left side of the controller the joystick control, when moved up and
down, will adjust the propeller speed causing the copter to gain or
lose altitude. Before attempting to take off, you need to make sure your
weight is properly balanced front to back and left to right to make
sure it will take off straight.
Note:Before your very first flight, its a good
idea to have a more experienced flier do a test flight and get it all
trimmed properly.
YawThe
yaw control rotates your craft left and right. The further you push it,
the faster it will rotate. Until you get really comfortable with
flying, it is best to keep the front of the craft pointing away from you
so you don’t get disoriented. As soon as your craft is facing you, the
controls are actually reversed and it is very easy to get confused with
the controls and end up crashing. Since multirotor copters are
inherently more stable than a helicopter, it is usually easier to
recover from getting disoriented but you still need to be pretty careful
about getting confused.
Pitch
The right joystick controls the pitch or angle of the copter to enabled
it to move forward/back and left/right. What this is a actually doing
is increasing the speed of the propellers in opposite relation to the
direction you push the joystick. If you push the joystick right, the
left side propellers will speed up to tilt the copter and cause it to
move to the right.
Hints
Start by standing behind your quadcopter and facing in the same direction as your drone. This way when you move the stick right, the quad will go right, etc.
When lifting your quad off the ground, immediately bring it up 2 feet
or more vertically. If you do not, the prop wash and ground effect will
make it harder to control.
Simulators
Not all simulators have models for
multirotor copters, but since flying a helicopter is identical, you can
use pretty much any R/C simulator to practice with. I personally use the ClearView R/C Simulator as I have
always spent a lot of time on simulators before any helicopter flight.
The nice thing is that if you can get half-way decent at flying a
helicopter in a simulator, you are in really good shape for flying a
quadcopter.
Summary
Flying a multirotor copter is relatively
easy and some people with no previous flight experience have had good
success with just firing up a quad and learning on the fly.
How To Fly A Quadcopter
Welcome to How to Fly a Quadcopter
This guide will show you everything you need to know to fly a
quadcopter. These tutorials will also apply to flying any other
multirotor. After reading this page, be sure to check out the flying
lessons.
The Controls
Below is an example of all the controls for flying a quadcopter and how each control works.
Roll tilts the quadcopter left and right by speeding up the rotors on one side and slowing them down on the other.
Pitch tilts the quadcopter forward and backward the same way that roll does.
Yaw rotates the quadcopter by speeding up all of
the rotors spinning in on direction and slowing down all of the rotors
spinning in the opposite direction.
Throttle controls the up and down axis by varying the overall speed of the rotors.
These controls also have other names, for example: roll = aileron, pitch = elevator and yaw = rudder.
Stabilization
There are usually 3 main stabilization modes for a quadcopter.
Rate, also know as manual, hard or Acro.
Attitude (not to be confused with Altitude), also know as self-level or Auto-level.
GPS-hold, also known as Loiter.
In the video tutorials I’ll be teaching you to fly in manual mode, it’s the hardest to learn but the most fun.
Before You Fly
When learning to fly a quadcopter, these are the things you should do
if you want to have the best experience while still flying safe.
Go to a park or big grass field.
Fly in the morning to reduce the chances of flying in wind
A normal airplane can fly forwards, climb upwards, dive downwards and turn (and roll) to the left and right. A helicopter can do all this plus has the ability to fly backwards, move sideways in any direction, rotate 360 degrees on the spot and hover i.e. stay airborne with no directional movement at all.
Helicopters might be more limited in their speed than planes, but the
incredible maneuverability mentioned above is what makes them so useful
in so many different situations.
Above: the directions a helicopter can move in and the associated name of control.
Controlling a helicopter
Helicopters require a completely different method of control than
airplanes and are much harder to master. Flying a helicopter requires
constant concentration by the pilot and a near-continuous flow of minute
control corrections.
A conventional helicopter has its main rotor above the fuselage, just aft of the cockpit area, consisting of 2 or more rotor blades extending out from a central rotor head, or hub, assembly.
A primary component is the swashplate located at the
base of the rotor head. This swashplate consists of one non-revolving
disc and one revolving disc mounted directly on top. The swashplate is
connected to the cockpit control stick and lever and can be made to tilt
in any direction, according to the cyclic stick movement made by the
pilot, or moved up and down according to the collective lever movement.
But first, to explain how the main rotor blades are moved by the pilot to control the helicopter, we need to understand pitch angle...
The basics of pitch angle
Each rotor blade has an airfoil profile just like that of an airplane
wing, and as the blades rotate through the air they generate lift in
exactly the same way as an airplane wing does [read about that here].
The amount of lift generated is determined by the pitch angle (and speed) of each rotor blade as it moves through the air. Pitch angle is known as the Angle of Attack when the rotors are in motion, as shown below:
This pitch angle of the blades is controlled in two ways - collectively and cyclically....
Collective pitch control
The collective control is made by moving a lever that rises up from
the cockpit floor to the left of the pilot's seat, which in turn raises or lowers the swashplate on the main rotor shaft, without tilting it.
This lever only moves up and down and corresponds directly to the
desired movement of the helicopter; lifting the lever will result in the
helicopter rising while lowering it will cause the helicopter to sink.
At the end of the collective lever is the throttle control, explained further down the page.
As the swashplate rises or falls in response to the collective lever movement made by the pilot, so it changes the pitch of all
rotor blades at the same time and to the same degree. Because all
blades are changing pitch together, or 'collectively', the change in lift
remains constant throughout every full rotation of the blades.
Therefore, there is no tendency for the helicopter to change its
existing direction other than straight up or down.
The illustrations below show the effect of raising the collective
lever on the swashplate and rotor blades. The connecting rods run from
the swashplate to the leading edge of the rotor blades; as the plate
rises or falls, so all blades are tilted exactly the same way and
amount.
Of course, real rotor head systems are far more complicated than this picture shows, but the basics are the same.
Cyclic pitch control
The cyclic control is made by moving the control stick that rises up
from the cockpit floor between the pilot's knees, and can be moved in
all directions other than up and down.
Like the collective control, these cyclic stick movements correspond
to the directional movement of the helicopter; moving the cyclic stick
forward makes the helicopter fly forwards while bringing the stick back
slows the helicopter and even makes it fly backwards. Moving the stick
to the left or right makes the helicopter roll in these directions.
The cyclic control works by tilting the swashplate and increasing the pitch angle of a rotor blade at a given point in the rotation, while decreasing the angle when the blade has moved through 180 degrees around the rotor disc.
As the pitch angle changes, so the lift generated by each blade changes
and as a result the helicopter becomes 'unbalanced' and so tips towards
whichever side is experiencing the lesser amount of lift.
The illustrations below show the effect of cyclic control
on the swashplate and rotor blades. As the swashplate is tilted, the
opposing rods move in opposite directions. The position of the rods -
and hence the pitch of the individual blades - is different at any given
point of rotation, thus generating different amounts of lift around the
rotor disc.
To understand cyclic control another way is to picture the aforementioned rotor disc,
which is the imaginary circle above the helicopter created by the
spinning blades, and to imagine a plate sat flat on top of the cyclic
stick. As the stick is leaned over in any direction, so the angle
of the plate changes very slightly. This change of angle corresponds
directly to what is happening to the rotor disc at the same time i.e. the side of the plate that is higher represents the side of the rotor disc generating more lift.
Above: the approximate layout of helicopter controls in relation to the pilot's seat.
Rotational (yaw) control
At the very rear of the helicopter's tail boom is the tail rotor
- a vertically mounted rotor consisting of two or more blades, very
similar to an airplane propeller. This tail rotor is used to control the yaw, or rotation, of the helicopter (i.e. which way the nose is pointing) and to explain this we first need to understand torque.
Torque is a natural force caused by any turning object and in a
helicopter it is caused by the engine turning the main rotor blades;
when the blades are spinning then the natural reaction to that
is for the fuselage of the helicopter to start spinning in the opposite
direction to the rotors. If this torque isn't controlled, the helicopter
would just spin round hopelessly!
So to beat the reaction of the torque, the tail rotor is used and is
connected by gears and a shaft to the main rotor so that it turns
whenever the main rotor is spinning.
As the tail rotor spins it generates thrust in
exactly the same way as an airplane propeller does, the difference being
that the helicopter tail rotor thrust is perpendicular to the fuselage.
This sideways flow of air prevents the helicopter fuselage from trying
to spin against the main rotor, and the pitch angle of the tail rotor
blades can be changed by the pilot to control the amount of thrust
produced.
Increasing the pitch angle of the tail rotor blades will increase the
sideways thrust, which in turn will push the helicopter round in the
same direction as the main rotor blades. Decreasing the pitch angle
decreases the amount of sideways thrust and so the natural torque takes
over, letting the helicopter rotate in the opposite direction to the
main rotors.
The pilot controls the pitch angle of the tail rotor
blades by two pedals at his feet, in exactly the same way as rudder
movement is controlled in an airplane.
NOTAR (NOTAil Rotor) is an alternative method of yaw control on some helicopters.
Instead of a tail rotor to generate sideways thrust, low pressure air
(created by a large fan in front of the tail boom) is expelled from
narrow slots at the rear (side) of the boom. The slots are opened and
closed by the pilot's pedals in the same way as tail rotor pitch is
controlled.
The amount of air expelled effects the air pressure around the tail
boom and the boom is 'pulled or pushed' one direction or the other, in
response to the varying pressure and the natural torque being generated
by the spinning main rotors. A natural effect (known as the Coanda Effect) involving air movement in relation to solid objects helps make the sideways movement of the tail boom happen.
NOTAR helicopters respond to yaw control in exactly the same way as
tail rotor helicopters do and have a big safety advantage - tail rotors
can be very hazardous while operating on or close to the ground, and in
flight a failing tail rotor can easily result in a crash. In addition to
that, NOTAR helis have a quieter operating noise level.
Throttle control
The throttle control is typically a 'twist-grip' on
the end of the collective lever and is linked directly to the movement
of the lever so that engine RPM is always correct at any given
collective pitch setting. Because the cyclic and collective pitch
control determines the movement of the helicopter, the engine RPM does
not need to be adjusted like an airplane engine does. So during normal
flying constant engine speed (RPM) is maintained and the pilot only
needs to 'fine tune' the throttle settings when necessary.
There
is, however, a direct correlation between engine power and yaw control
in a helicopter - faster spinning main rotor blades generate more
torque, so greater pitch is needed in the tail rotor blades to generate
more thrust.
It's worth noting that each separate control of a
helicopter is easy to understand and operate; the difficulty comes in
using all controls together, where the co-ordination has to be perfect!
Moving one control drastically effects the other controls and so they
too have to be moved to compensate.
This continuous correction of
all controls together is what makes flying a helicopter so intense.
Indeed, as a helicopter pilot once said to me... "You don't fly a helicopter, you just stop it from crashing"!
Getting a firm understanding of rc airplane controls.
The number of controls necessary or required differs between planes;
the simplest rc airplanes will have just one single control while the
more complex planes may have five, six or more. Your 'average' rc plane
will have three or four controls, this is by far the most common number.
Incidentally, if you're completely new to the radio control flying
hobby, a controllable function of any rc model is referred to as a channel so an rc airplane with control to, say, four functions will be called a 4 channel plane, sometimes abbreviated to just 4 ch.
RC airplane controls are, of course, the same as those
found on real airplanes and they control the model in exactly the same
way.
The four primary controls of an rc airplane are throttle, elevator, ailerons and rudder. The elevator, ailerons and rudder are known as control surfaces and the picture below shows where these main controls are located on a fairly typical 4 channel rc 'sport' airplane....
Above: location of ailerons, elevators and rudder on an rc airplane.
Which controls do what?
Now you know where the primary rc plane controls are located, let's take a look at each one...
Throttle
Throttle controls the speed of the engine and hence how fast or slow the propeller turns.
On a glow plug (or petrol) rc airplane engine the throttle works the
same as any internal combustion engine throttle, by changing the amount
of fuel and air that enters the combustion chamber of the engine. The
carburettor is operated by a single servo connected to the venturi of
the carb, which opens and closes (thus changing the fuel/air mixture) in
response to your throttle stick movements on the transmitter.
On an electric rc airplane the throttle is usually referred to as motor power rather than throttle. Very basic electric rc planes (i.e. toy ones) might not have proportional control to motor power but just a simple on/off switch instead.
Electric airplanes that do have control to motor power have an electronic speed control, or ESC, that controls power to the motor in direct response to your Tx stick movements.
In the air throttle/motor power not only controls the forward speed
of the airplane but also, more importantly, the rate of climb and
descent, because different amounts of lift are
generated at different airspeeds. For example, if your landing approach
path is too low you can make the airplane rise slightly without changing
speed much, simply by opening the throttle instead of using up
elevator. Conversely, closing the throttle will cause the airplane to
sink before the speed reduces.
Using throttle/motor power in this way is the correct way to fly your rc airplane, but many pilots use the elevator to control altitude and rates of climb and descent.
Elevators
The elevators are the hinged section of the tailplane, or horizontal
stabiliser, at the very rear of the airplane and are the single most
important control surface.
Elevators control the horizontal pitch attitude of the airplane, in other words whether the nose of the plane points upwards or downwards.
When elevators are in the up position (upward deflection) the nose of
the airplane is forced to point upwards, and with the elevators
deflected downwards then the nose is forced downwards. This resulting
nose up/nose down pitch attitude comes about as the upward/downward
deflection of the elevators changes the amount of down force being
generated by the tailplane.
It's worth noting that a plane can
still fly level, or even be descending, with a very nose-up attitude but
a nose-down pitch attitude will almost always result in the plane
entering a dive, thanks to our friend gravity!
Elevators directly effect the plane's airspeedmore than the need to climb or dive.
Elevators should be used in conjunction with rudder and/or ailerons when making a turn.
Ailerons
Not all rc airplane controls include ailerons, in fact the majority
of 3 channel radio control airplanes use rudder instead. But where
fitted, ailerons control the roll of the airplane about its longitudinal axis (imagine a straight line running through the centre of the fuselage, from nose to tail).
Ailerons work in pairs and are found on the trailing (rear) edge of the wing, and they work opposite to each other i.e. when one aileron moves up, the other one moves down and vice versa.
Ailerons work by changing the amount of lift generation
over the wing. As an aileron moves upwards so it disrupts the smooth
airflow over the wing surface and so lift is reduced slightly on that
wing. Over on the other wing the aileron moves downwards and increases
lift slightly. As a result, the airplane tilts and hence rolls towards
the side that's experiencing less lift.
When up elevator is applied at the same time as ailerons, the
airplane is pulled round in to a banked turn; the ailerons cause the
plane to roll and the up elevator causes the nose to pitch round in that
direction.
Ailerons are used in all aerobatic maneuvers that involve a rolling motion.
Rudder
The rudder is the hinged section of the fin, or vertical stabiliser, at the rear of the airplane.
It's used for directional control by changing the yaw of the airplane and works in the correct sense i.e. moving the rudder to the left causes the airplane to turn left and vice versa.
Applying rudder makes the nose of the airplane point to the left or
right, but rudder alone does not make the airplane roll like ailerons
do. It's actually the dihedral, or the upward 'V' angle
of the wing when viewed from the front, that makes the plane roll when
rudder is applied; a plane with very little or no dihedral will have a
much flatter turn when rudder is applied.
Rudder is also very important on the ground, it's the one control
that will keep your rc airplane tracking straight during a take off run
or landing roll if your plane isn't fitted with a steerable nose or tail
wheel.
Other RC airplane controls
Other important controls found on more complex rc airplanes include flaps and retractable landing gear, or 'retracts'.
Flaps are located on the trailing edge of each wing,
between the aileron and fuselage. They're used to generate more lift at
slower flying speeds and, at greater deflection, to slow the airplane
down close to landing by causing excessive drag.
Unlike ailerons,
flaps are connected in such a way that they both drop exactly the same
amount together so as not to upset the roll attitude of the plane when
they are deployed.
Flaps are operated with a toggle switch or rotating dial on the
transmitter. A dial is the better option because this allows the pilot
to use as little or as much flap as he wants, according to the
situation. Flaps operated by a single position (on/off) toggle switch
will be all or nothing.
When a lesser amount of flap is used it's quite common for the
airplane to pitch upwards as soon as the flaps are lowered, this is a
result of the extra lift being generated and the pilot needs to be aware
of this happening before he activates the flaps.
Retractable landing gear (undercarriage) is landing gear that folds away into the airplane's wings or fuselage once the plane has taken off.
Retracts are often used on larger rc airplanes, particularly scale
models where the real airplane has retractable undercarriage. Larger
non-scale airplanes can also have retracts, particularly competition rc
airplanes where it's necessary to reduce the amount of drag on the plane
in the air. Obviously an airplane with no landing gear hanging below it
experiences a lot less drag than one with.
Retracts can be operated mechanically by a servo, driven by
compressed air or more recently electric worm-drive. The retraction of
the landing gear is operated by the flicking of a single switch on the
transmitter, typically either on the 5th or 6th channel.
Control surface mixing
Some rc airplanes are designed in such a way that they cannot have
separate ailerons and elevators - delta-wing planes, for example. When
this is the case control surface 'mixing' is necessary and this is only
possible on computerised rc radios that offer a mixing capability.
When elevators and ailerons are combined together, or mixed, they become elevons. They look just like elevators but move together, as elevators do, and individually, as ailerons do. In short, one pair of elevons does the job of elevators and ailerons. Flaperons
are control surfaces that mix the actions of ailerons with flaps. In
other words, one pair of control surfaces along the trailing edge of the
wing take on the job of aileron control and flap control, when needed. Spoilerons
are, in effect, the inverted version of flaperons. Spoilers are often
found on large rc gliders and operate by the control surfaces moving upwards
as opposed to flaps that drop down. When spoilerons are deflected, the
amount of lift is drastically reduced and so the glider's rate of
descent quickly increases, enabling the pilot to land it in a smaller
space.
There are other types of rc airplane control mixing too, but those
listed above are by far the most common that you'll encounter.
Channel mixing is another type of mixing supported
by most modern computer radios. I this case two separate channels can be
mixed to operate together.
A common example of channel mixing is
an aileron and rudder mix; a small amount of rudder is automatically
applied when you operate the ailerons. The purpose of this is to produce
a cleaner turn and can prevent the effects of adverse yaw, a common situation whereby the tail drops during a turn due to increased drag over the higher wing.
The very First example of radio control was demonstrated in New York
City in 1898. Its inventor—Nikola Tesla—was a 43-year-old immigrant who
was duly awarded U.S. Patent no. 613,809 on November 8, 1898. It was
only one of 113 U.S. patents that this prolific genius received during
his lifetime. Many electrical engineers and historians regard his basic
inventions as the foundation of the 20th century as we know it. In the
decades that followed, the military and its suppliers attempted to
implement Tesla’s work in various R/C projects—including boats and
aircraft—without very much fanfare.
By the middle of the 1930s, miniature airplanes were just beginning
to be powered by very small gasoline engines. An R/C contest event was
even scheduled for the 1936 model aircraft Nationals in Detroit. It was a
little premature; not one entrant showed up! The following year
however, must be regarded as the true beginning of R/C.
R/C PIONEERS
Several men who were active in amateur radio became interested in the
possibility of controlling model planes by radio. Two of these early
pioneers were Ross Hull and Clinton DeSoto. Both were officials of the
American Radio Relay League (ARRL), which is the governing body of ham
radio operators. Hull was a very gifted radio designer whose
achievements include the discovery and eventual explanation of the
tropospheric bending of VHF radio waves. Since his youth in Australia,
Hull also happened to be an avid modeler. Hull and his associate DeSoto
successfully built and flew several large R/C gliders in the first
public demonstration of controlled flights. Their sailplanes made more
than 100 flights. (See the January and August ’38 issues of Model
Airplane News). Tragically, Hull died one year later in 1939 when he
accidentally contacted 6,000 volts while he was working on an early
television receiver. DeSoto died a decade later.
COMPETITIVE FLIGHT
The 1937 Nationals R/C event attracted six entrants: Walter Good,
Elmer Wasman, Chester Lanzo, Leo Weiss, Patrick Sweeney and B. Shiffman.
Lanzo won with the lightest (6 pounds) and the simplest model plane,
although his flight was a bit erratic and lasted only several minutes.
Sweeney and Wasman both had extremely short (5-second) flights when
their aircraft took off, climbed steeply, stalled and crashed. Sweeney,
however, had the distinction of being the first person to attempt an R/C
flight in a national contest. The other three entrants weren’t able to
make any flights at all.
BIRTH OF THE REED
One of them—Weiss—was an 18-year-old aeronautical engineering student
who had constructed a very large, 14-foot-wingspan RC model. He and an
electrical engineering student—Jon Lopus—had devised a very
sophisticated, innovative RC system consisting of six tuned reeds that
reacted to audio tones. The reed-control system became widely accepted
in the 1950s. During the 1937 Nationals, however, Weiss wasn’t able to
start his plane’s Ferguson twin-cylinder engine. He went on to
successfully operate an avionics manufacturing company.
R/C EVOLVES
The 1938 Nationals wereonce again hosted by the“Motor City.” Although theR/C
entry list had grown to 26 entrants, only five fliers showed up on the
field. One of the newcomers was DeSoto, who entered a 14-footwingspan,
25-pound, stand-off-scale model of a Piper Cub that was powered by a
Forster twin-cylinder engine. Each of the four separate receivers on
board used a gas-filled Raytheon RK-62 tube in a super regenerative
circuit to activate its own sigma relay. His plane placed second, but it
isn’t clear whether or not it actually flew. Oddly enough, these first
contests required only that contestants demonstrate their R/C systems in
a static position on the ground to win a runner-up award.
Walter Good was the only contestant who attempted a controlled flight
in the face of the 20mph winds. Even though it ended in a crack-up,
Walt was awarded first place. A truly convincing demonstration of R/C
flight by a powered miniature aircraft would have to wait until the
following year. Eleven R/C fliers showed up at the 1939 Nationals at the
Detroit Wayne County airport. For the first time, a 100-point system
was adopted by the judges. Points were given for craftsmanship, actual
R/C operation in a static preflight mode on the ground and a variety of
flight maneuvers.
GOOD FLIERS
That was a rewarding year for Walter and William Good—23-year-old
twins from Kalamazoo, MI. Bill was a licensed ham-radio operator with
the call letters W81FD. Their aircraft—named K-G—was a slightly
modified, high-wing monoplane.
(See the K-G story in the January ’91 issue of Model Airplane News.)
This first stable gas model was designed by a former editor of Model Airplane News—Charles Hampson Grant.
Their radio and control mechanisms were the essence of simplicity. At
a time when all of their competitor’s planes carried receivers with 3-
and 4-tube circuits, the Good brothers’ radio receiver was a one tube
affair with a minimum of electrical components. Their homemade relay was
so sensitive that it could be activated by a current change of 1/2
milliamp! They also designed and made their 1 -ounce, rubber-band
powered escapement mechanism. Before going to the Nationals in 1939, the
two brothers had accumulated over 60 controlled flights in southern
Michigan. Their diligent efforts paid off with a first-place score of 89
points; the second-place winner scored only 11 points. The Good
brothers repeated their first place win in the 1940 Nationals and once
more after the end of WW II, in 1947.
Their historic R/C model airplane, which they affectionately named
the “Guff,” was presented to the National Air and Space Museum in
Washington, D.C., in May, 1960, where it can be seen today. Both
brothers continued their education and subsequently earned doctorates in
physics. After pursuing careers in electronics research and teaching,
they retired, but they’re still very active in electronics. Walt lives
in Florida, and Bill resides in upstate New York. They communicate
constantly with each other using their ham radios.
JOSEPH RASPANTE
No story on the early days of R/C would be complete without
recognizing the work of Joseph Raspante. Unlike most of the early
pioneers of R/C, who were basically model airplane builders teamed up
with ham-radio specialists, Joe Raspante was a superb designer and
builder of early gas models as well as a competent electronic
technician. His R/C system was unique in that he used a telephone dial
to select various control functions. He placed second in the 1939 R/C
Nationals and third in the 1940 event. Raspante was generous, and he
shared his knowledge with young builders in years that followed. Walter
Good remembers that when thieves stole his brother’s R/C transmitter
from their hotel the day before the 1940 Nationals, Raspante offered the
use of his own transmitter. This gesture was especially meaningful,
because the Good brothers had defeated him in the 1939 Nationals.
Raspante finally won the first place he yearned for at the 1946 NY Daily
Mirror contest at Grumman airfield. It was my privilege to see him fly
there. With the advent of the transistor and the integrated
microcircuits, today’s R/C builder hardly has any of the frustrations of
the early pioneers.
In retrospect, however, we see that most of the pioneer’s dedicated
efforts were largely foiled by overly complex electrical designs. But
without their perseverance, I doubt that R/C flight would have
progressed as quickly to where it is today.
A conventional helicopter has its main rotor above the fuselage, just aft of the cockpit area, consisting of 2 or more rotor blades extending out from a central rotor head, or hub, assembly.
At the very rear of the helicopter's tail boom is the tail rotor
NOTAR (NO TAil Rotor) is an alternative method of yaw control on some helicopters.
Throttle controls the speed of the engine and hence how fast or slow the propeller turns. 
