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Basic RC Crash Course
Basic RC
Crash Course
This is a paper that was put together to help
newcomers with the great hobby of Radio Control. It is the rough draft so bear
with us. It will be refined as time goes along but look through it and copy it
if you want. That is why this page is in black and white. Hope it's of use.
Thanks -- JKA
It occurred to us that an
awful lot of you folks are purchasing your first airplanes from JKA and haven’t
a clue what your doing – you just know that flying a radio control plane looks
like a blast and want to learn. Or maybe you know a little bit about airplanes
but have some questions about some of the little details that those of us who
have been in the hobby for years forget to mention. If you find yourself in one
of these camps, then this paper may help you on your way to becoming a
successful RC pilot. The first portion of the text simply defines some of the
more common terms used by radio control guys. The rest of the text is in major
sections. All articles can be located quickly with the following links.
Quick RC Definitions will answer the question - What
is/are --- (These are not in alphabetical order but are grouped in a
logical topical progression): Channels; Crystals/Frequency; Sticks; Antenna; Range check; Servo; Control Surface; Servo reversing; Control
horns; Z-Bends; Ailerons; Fin and Rudder; Stabilizer
and Elevator; Wing; Dihedral;
Banking; Leading
edge; Trailing edge; Airfoil; Chord; CG/Balance point; Fuselage; 1/2A; Engine displacement;
Main topic sections
Setting up the
plane and radio system
Control setup - which
stick does what?
Trim levers - levers on a
diet
Electric flight system - tips
on hooking it all up
Batteries,
connectors, and a short course on soldering
Using a speed 400
motor
Gas engine setup - this section is not finished but it is covered
in detail in the T52 building instructions
Flying tips - your ready to
fly, now what!?!
First I would like to define
some of the more important terms that you may hear bandied about but are not
sure what the heck we’re talking about. I know this would technically be called
a glossary, but it always irritates me when I have to flip to the back of a book
to find out what a word means, so let’s do that first.
Three Channel, Four Channel, Six Channel, English
Channel, etc.: Radio Control
airplanes use a transmitter and a receiver that work together to translate an
input at the transmitter to some sort of motion in the aircraft. Since we like
to control several things at once, such as the speed and direction it is going,
we need a separate channel for each different action. So, depending on your
budget and needs, you can usually get radio systems with 2 to 8 channels.
Crystals/frequency: No, this isn’t New Age stuff. Crystals are used by
the radio system to tune the transmitter to the receiver so that they can
communicate with each other. Aircraft radios have been assigned by the FCC to
use the 72mhz frequency spectrum (mhz stands for mega-hertz, pronounced
mega-hurts – how it feels to tangle with a spinning prop!). In that spectrum are
frequency channels 11 through 60. This allows us to fly more than one plane at a
time – 49 to be exact! But don’t try that, airspace gets way too crowded! The
crystal is usually a little metal thing with two pins on it that will push into
a socket. They are usually located on the front or side of the transmitter,
sometimes behind a little plastic plug, and are usually in a little slot on the
receiver. The Transmitter crystal should have TX 72.xxx and the channel number,
and the receiver crystal should have RX 72.xxx and should be the same numbers as
the transmitter.
Sticks: referring
to the levers on the transmitter that you move back and forth to turn the
aircraft. Most radios have one or two sticks. On two stick transmitters with at
least 4 channels, the right stick will control the ailerons when moved right or
left and will control the elevator when moved up or down. The left stick will
control the rudder when moved right or left and the throttle is controlled by
the up and down motion with the idle position at the bottom and full throttle at
the top. We will set our plane up later in this text and explain exactly how the
sticks should work each corresponding part of the plane.
Antenna: very
important to have extended before launching an aircraft. Be sure to let the
receiver antenna wire extend fully also.
Range check:
Before flying your plane it is a good idea to check your range (for cinnamon
rolls, of course, or turkey or a pot roast or something). Just kidding - wrong “range”, what we are going to do is see
if our radio and receiver are functional before we actually let ‘er fly and if
you did check the kitchen’s range and found something good – have it now because
there’ll be no time once your in the air. Your radio system manual should tell
you how to do this. The way we do it is to turn the transmitter and receiver on,
leave the transmitters antennae collapsed and slowly walk away from the receiver
while working the controls. Have a friend stay with the receiver and signal when
the controls start to glitch or stop completely. You should be able to walk at
least 50 to 100 feet away before that happens. If your system passes this test,
it should fly just fine. Now go finish your cinnamon roll.
Servo: these are the
little marvels that turn your stick movements into useful work at the aircraft.
They can be very tiny, we call them micro servos, or very large for giant
planes. They have a wire with three colors and a plug attached to them for
hooking to the receiver. The colors are usually red and black for + and –
battery power and white, blue, orange or yellow for the signal. The signal wire
is the one that tells the servo to move. As the servo receives the signal from
the receiver, it will turn the output shaft right or left. Servos are supplied
with servo arms to transfer the twisting motion from the servo to linier motion
for the control surface. Don’t forget to tighten the little screw that holds the
arm to the servo! The servo arm usually has a series of holes punched in them
from the center out. The farther from the center, the more movement you will see
at the control surface.
Control Surface: Control surface is any part of the wing or tail that
moves to direct the air flowing over it, thereby making the plane go up or down,
right or left, or banking (tipping) right or left.
Servo Reversing: On virtually all current radio systems, there are
little switches on the bottom, front, or back of the transmitter that will
reverse the direction the servo moves for a given stick movement. This is very
helpful when setting up your airplane because no matter what side of the servo
you install the servo arm, you can always get the correct movement for the
control surface simply by changing the switch on the transmitter.
TIP: Always check that the control surfaces are moving
the correct direction before flying! Hand/eye coordination takes a dive with the
plane if one servo is reversed.
Control Horns: Not to be confused with bull horns. Control horns are
screwed to the control surfaces and hooked to the servo with a wire or push rod.
They usually have a series of holes punched in them from the bottom to the top.
Placing the push rod closer to the control surface will increase the movement of
the surface. So by using a combination of holes in the servo control arm and the
control horn, you can get just the right amount of control “throw” (range of
motion) on the controlled surface. So, if you want a lot of control movement,
use the hole farthest from the pivot on the servo and the hole closest to the
controlled surface at the horn, and visa versa for a small amount of movement.
Most plans have a recommended amount of control movement. It’s a good idea to
follow the recommendations to start and then adjust to suit your flying ability.
A plane that is too sensitive to control input is very difficult for a beginner
to fly so experiment a little to find your comfort zone. Remember, bull horns
control crowds, control horns control planes. And that’s no bull.
Z-bend: Control hookup requires
some type of linkage to hook the servo and control surface together in a manner
that allows free movement back and forth. One way has been around for as long as
things have needed linking, and we call it the Z bend. Simply put, the push rod wire will have a right angle bend to go through
the hole in the control horn or servo arm and then another right angle bend to
form a keeper so the wire is impossible to unhook without some inordinate
gymnastics. Study the Z-bend page for an illustration on
how to make the bend in a very simple and easy way. To make control hookup even
easier, we have a little product we call pushrod connectors that we use on the
control horns. Using the connectors lets you get away with making only one
Z-bend at the servo arm and the other end of the pushrod slips into the
connector and clamps down with a set screw at the control horn end. This way you
can center the servo, loosen the set screw and center the control surface. We
use them on all controls - rudder, elevator, or aileron. Just check the set
screw occasionally to make sure it is tight. Planes do funny things when control
surfaces don't control.
Ailerons: Ailerons refer to the movable part of the back edge
of a wing that will cause the plane to tip or “bank” right or left. We use a
control horn on each aileron to hook it to the servo. They are hooked up in such
a way that when the aileron stick is move to the right, the right aileron
deflects up and the left aileron deflects down, thereby banking the plane to the
right. Just the opposite occurs with a left stick input.
Fin: The vertical
portion of the tail. I liken this part to a weather vane because it keeps the
plane pointing in the right direction. It can be called a vertical stabilizer
also but what ever you call it, most aircraft would be lost without it. The fin
usually has a rudder attached to it for directional control. Some of our planes
do not use a rudder because we use ailerons to bank the plane and the elevator
to turn the plane during the bank. This keeps everything simple and except for
limiting some aerobatic maneuvers, allows good control.
Stabilizer and elevator: The stabilizer is the fixed portion of the
horizontal tail surface and elevator is the movable control surface.
Instructions sometimes refer to the “stab”, this isn’t gruesome – just an
abbreviation for stabilizer. The stabilizer does exactly what the name implies.
If the plane pitches down, the stab wants to bring the nose up, if the plane
pitches up the stab works hard to bring the nose back down. Assuming, of course,
that everything else is in correct balance. We will cover balance later, but the
main job for the stabilizer is to keep the plane flying level. The elevator on
the other hand, will push the tail up or down depending on the control input. It
is usually the last 15% to 25% of the horizontal tail and is hooked to the
elevator servo with a pushrod and control horn.
Wing: We all know
what a wing is, but did you know that the wing is the single greatest factor in
what determines how a plane flies!? Even missiles have wings so as a general
rule, the smaller the wing area (the square inches of the wing surface) the
faster the plane has to fly to stay airborne. That is why our trainer has a
large wing area for the size of plane. When beginning to fly, a plane should
have lots of wing area (in our opinion) so that it will fly slow enough to
recover from mistakes. The only real drawback is that the larger wing will catch
wind, so a calm day is in order. As you get more proficient at controlling your
plane, you should be able to handle a faster, more maneuverable aircraft.
Dihedral: If you look at
airplanes from the front or back you will notice that most of the wings and some
of the horizontal stabilizers are angled up from the fuselage. This is called
dihedral and it is used to help add a little stability to the plane. Our T52 has
a high wing with lots of dihedral and is designed to provide enough stability to
help the plane to return to level flight with little or no control input. Since
the fuselage is lower than the dynamic center of gravity, it will actually act
like a pendulum and tend to right the plane from a banked position. Dihedral can
be large, as in the case of the T52, or shallow. Some planes have no dihedral
and are usually used for aerobatics. You could even run across some planes,
usually jets, with "Anhedral" where the wings slant down instead of up. The F18
Hornet and F4 Phantom are two such examples.
Bank or Banking:
Tipping the wings using the ailerons is what we call banking the plane
and is usually followed by some elevator input to bring the plane around in a
turn. If you have a rudder, you can bank a plane and hold the angle using
opposite rudder input to keep the plane from falling out of the sky. Unless it
is a very slight bank, you should add either rudder or elevator to the ailerons
or you better right the plane quickly because most planes will continue to fall
out of the sky or spiral out of control to the ground. And that, if done too
many times my friends, will no doubt break the bank.
Leading edge: Front edge of a flying surface, i.e. wing, fin, or
stab.
Trailing edge: Back edge of a flying surface.
Airfoil: An
invisible sword. Not really! All flying surfaces like wings, fins, and
stabilizers have an airfoil. It could be flat or curved. To make the most
efficient use of the air flowing over the wing, airfoils start with a blunt
leading edge and broaden out to the thickest part at about 1/3 back from the
leading edge and then gradually taper back to a sharp trailing edge. Good,
efficient airfoils take a lot of engineering and testing to design so we use the
tried and true method of finding just the one we need on our trusty computer
program.
Chord: distance from
the leading edge to the trailing edge at any given point on a wing or other
flying surface.
CG / Balance Point: All aircraft have to be in perfect balance in order
to fly well. In most instructions this is referred to as the ”CG” or center of
gravity. On a straight wing, one with no taper, the CG is generally at 25% to
30% of the chord as measured from the leading edge. The stability of the
aircraft is greatly affected by the location of the CG. For trainer planes, or a
new model that has not been flown before, it is best to set the CG closer to the
25% mark because it will behave in a much more controllable and predictable
manner. For highly maneuverable aerobatic aircraft, you would gradually move the
CG farther back on the wing until you achieve the flying characteristics you are
looking for. If the CG is too far back, the aircraft will become tail heavy
causing the nose to pitch up, stalling the plane and leading to a very exciting
flight and a spectacular crash. So, move the radio components around or add
weight if you have to, but to begin with, always balance the plane at the
recommended CG point.
One more note about CGs. On
tapered or swept wings the CG is still usually about 25% to 30% of a chord but
you can’t simply measure 25% of any spot on the wing and call that the CG. It
takes some fancy calculations or a graphical solution to find the ”mean
aerodynamic chord” I could do some corny humor with that one but I’ll spare you
the pain. If you really want to know how to find the mean aerodynamic chord,
there are several good articles in model airplane magazines or checkout most any
book that centers on designing your own aircraft. But the safest thing to do is
follow the kit manufacturers recommendations for setting the CG, whether
straight or tapered.
Fuselage: The
fuselage, abbreviated “fuse”, just holds it all together. Unless, of course, you
have a flying wing, in which the wing then becomes the sum total of the plane.
However, most conventional aircraft use a fuselage to hold the wing, tail
surfaces, and motor in the correct relation to each other. The flight
characteristics of an airplane can be greatly affected by the distance the tail
is from the wing and/or the length of the nose. We call this nose moment and
tail moment, and if you get these wrong – it could be a Kodak moment. Believe
me, I’ve had some incredible flights with new designs because the moment wasn’t
right. Had nothing to do with the time of day either. A moment is simply the
distance an object turns about a pivot point. So when a construction article
talks about a long or short tail moment, it is referring to the distance between
the tail group and the wing. It can be calculated exactly from the CG of the
wing to the CG of the horizontal stabilizer. As a general rule, the longer the
tail moment, the more stable the plane will be and the smaller the tail surface
area needed to adequately control the plane. And a short tail moment could mean
a hot little squirrelly plane with larger tail surfaces. The term “short
coupled” refers to this type of plane. You don’t want that for a first
plane. Look, instead, for a plane with good proportions and a longer tail
moment. You will have much greater success in learning to fly.
The nose moment affects the
plane a little differently. On conventional powered planes, we usually hang the
motor out on the front of the fuselage. Very simply, a longer nose means the
tail will have to work harder to rotate the plane in any given direction except
down. This is not a hugely critical thing but it can affect the aerobatic
qualities of an aircraft.
1/2A: You may have heard some planes
or motors referred to as 1/2A size. This is a term that is used to specify the
smallest engine size made up to .10 cubic inch (I think, some of you old timers
out there might be able to set me straight on that). So our Norvel .061 and .074
engines are of the 1/2A size. The term came about from early free flight
competitions where the different classes were split up according to engine
displacement. 1/2A size kits would then be designed to run on engines in the
usual .049 to .09 size.
Engine
displacement: Since we are talking about gas engines you probably have already noticed the myriad of
sizes of engines out there. Generally the size is called out in cubic inches so
that .049 is about one twentieth of a cubic inch and a .10 size is one tenth of
a cubic inch and so on. Really big engines are one cubic inch and larger such as
1.25 engine. Our combat planes are designed for engines in the .15 to .25 range
with some adventuresome gentlemen stuffing .40 to .60 size engines into them.
Kids, don't try this at home. I have noticed that some engines are being sized
in metric units and instead of cubic inches, the size is denoted by cc, cubic
centimeters. Our T52 Trainer will fly excellent on 1/2A engines from .049 to .09
and some folks are installing .10 and .15 engines in them for super
performance.
Setting up the plane and
radio
Well that about covers the
most often used terms in RC aircraft. Now lets set a plane up and see how it all
fits. I will use our T52 Trainer as the example here but most of this will apply
to other planes. If you are using our T52, you should have a complete set of
instructions and your plane should be completed already. What we will cover is a
little more detail about how and what you do to get it ready for flight.
First, familiarize yourself
with your radio system. READ the directions that came with it. I know, we guys
(assuming the reader is a guy – the ladies are much more apt to read the
instructions) think we know it all - it’s a male thing, but read the
instructions for everything you buy to make this kit flyable. I’ve ruined things
because I didn’t read the instructions (Normally I wouldn’t admit that - but I
know you have too).
I will assume you know
nothing about a radio control airplane so we’ll begin with the very basics.
After looking the radio system over, plug everything in and make sure it all
works (click here for wiring illustration). If you are
using gas power for your T52, you will need a minimum of two servos, one for
rudder control, one for elevator. If you plan to use a throttle, you will need a
third servo, preferably a micro servo. Some of the smaller gas motors do not
have a throttle so the third servo would be unnecessary. If you were doing an
electric plane, you would use a speed control on the throttle channel. Check
your radio instructions for the correct servo and battery hookup and make sure
the plugs are in correctly or the system will not work. Make sure the batteries
are charged (or fresh, if throw-away kind) NEVER fly if there is a question
about the condition of the batteries.
After every thing is plugged
in, move the sticks on the transmitter and you should hear and see the servo
shafts move. If they aren’t yet attached, find your servo arms and stick them on
now. They will be little plastic things with a screw hole in the middle or one
end and a series of small holes along the length. Some servo arms are actually
round wheels that can be drilled for custom type installations.
Since I am now assuming your
plane is completed, that then would preclude that you have installed and
attached your servos to the elevator and rudder according to the kit
instructions. So now when you turn on your receiver and transmitter, you should
have elevator and rudder movement when you move the transmitter sticks and the
throttle servo (if you have one) should move back and forth. Question is, do you
have the correct thing moving for a given control input? It is also a good idea
to make sure your servos are not binding as they move the control surface or
throttle through the full range of motion. Check your distance your control
surface moves and adjust to the manufacturers recommendations. In the case of
the T52, we need lots of rudder so 3/4" to 1” movement either direction is good
but the elevator is much more sensitive so beginning pilots might set them so
they only move 1/4" up or down. See the discussion above on CONTROL HORNS for
how to adjust and set up the control throws as we say in RC lingo. During
this exercise, you may have a question as to which stick controls what surface
so read on. The following is how we normally set up our planes. If you are left
handed, I think some transmitters can be changed to swap the controls - check
the manual.
Control
setup
Click here to see the illustration on
control setup it may take a bit to load the page but I think it illustrates
the setup very well
Now, this is a little tricky
so read carefully. There are two different ways to set up the controls on
airplanes. On the T52 trainer, we are using only the rudder and elevator to
control the aircraft. So, I recommend always keeping the primary controls
on the RIGHT stick. The rudder will be moved right or left by moving
the right stick right or left. The elevator will move
up by pulling the right stick back or down and will
move down by pushing the right stick up or forward.
I know that may seem confusing, but think of yourself as a P51 fighter pilot
with a “stick” in your hot little hand. The fighter pilot pulls back to climb
and pushes forward to dive! We want to set our transmitter up the same way, so
if you lay the transmitter on the table in front of you, pull the stick back to
climb (up elevator) and push forward to dive (down elevator).
Now here’s the tricky part!
If you are building a plane with ailerons plus a rudder, the ailerons
would then occupy the right stick and the rudder control would be
delegated to the left stick. The elevator would stay with the right
stick. If you are building one of our combat fighter planes, we never use a
rudder. In that case the right stick would be used solely for the directional
control of the craft and the left stick only for the throttle. Which reminds me,
the up and down movement on the left stick is always for the throttle. You will
notice that instead of automatically centering itself, it is on a detent ratchet
so it will stay at the throttle setting you leave it. Up is full throttle and
down is idle. It is a good idea to set the throttle so that when the trim lever
is all the way down and the stick is all the way down, the engine will die. That
way you can completely kill the engine should you get yourself in trouble. Did any of that make sense!?!? OK, I know
it didn’t so study the pictures and maybe that will help clear things up.
Trim Lever
What’s a trim lever, you
say? On most transmitters, there are two little sliders, one below and one
beside each stick. These offer fine adjustments to the stick and allow you to
trim the controls if the plane doesn’t fly straight. During flight, if the plane
turns slightly to the left, move the bottom slider a couple clicks to the right,
if it climbs slightly, move the side slider a couple clicks forward until the
plane flies straight and level.
Up to this point you should
have a plane that has the radio installed and working controls. Some of you have
used gas engines to power your plane and others electric power. If you did the
electric version you should have the motor installed or loosely installed
already. You may have to pull it out if you haven’t soldered it up yet. I think
electric is a nice way to go but it is a little more involved and a little more
costly at first. So you don’t want to make any mistakes because a nanosecond of
brain fade is all it takes to sizzle a $40 controller. This next section will
cover electrics in detail and there are wiring diagrams on our web to help do
the hook up, complete with pictures and diagrams. I will cover the gas engine
installation after the electric section
Electrics
Some of you have purchased
our kit and are planning on using electric motors to fly it so before we leave
the bench, let’s set up the motor control too. If you are using electrics you
should have, in addition to the radio setup, an ESC or electric speed control.
You will need a speed control that is capable of handling the amount of power
that your electric motor will draw. We measure that in Amps and most small Speed
400 systems should pull a maximum of 10 amps so you will need an ESC that will
handle at least 10 amps. We have several that are very well suited for this
application. In addition to the ESC you need a couple of battery packs, quick
disconnect plugs, and a charger. We recommend a controller with a Battery
Eliminator Circuit, BEC, because it will split some power off from the motor
battery to run the receiver. As the plane is flying, the battery will run down
and as the voltage level drops, the BEC will turn off the motor and leave enough
battery power to safely power the receiver and fly the plane for a good amount
of time.
ESC hookup
(Click here to get to the wiring
diagrams page. It illustrates very well how to hook things up including wiring
the batteries and Sermos connectors)
First, read the instructions
for the speed control very carefully. One wrong connection and smoke will engulf
you. Most controllers have four heavy gage wires coming from them. Two of them
will be attached to the battery and the other two will be the variable output to
the motor. Read the instructions carefully and look closely at the tiny words on
the controller, you should see the words “Battery” and “Motor” designating the
appropriate set of wires. DO NOT accidentally hook the battery to the motor
wires. Check and double-check your connections before powering up the system.
It is a good idea to insert
a fuse between the motor and the ESC. For speed 400 motors, I use a 10 Amp
Automotive mini fuse with the spade lugs on it and use plain old automotive
female spade connectors to hook it up. This makes it very easy to change a blown
fuse. Take the two wires marked “Motor”, they should also be marked +,-, and cut
the plus wire in half. Use two female spade connectors and solder or crimp one
on each end of the cut wire. Now slide the spades onto the lugs of the fuse and
notice how easy it will be to change the fuse. Incidentally, you will need a few
basic tools to build and fly model airplanes and if you do electrics you should
get acquainted with good soldering techniques and have some crimping tools.
Crimping is OK for low amperage systems like speed 400 stuff, but for high
amperage systems, you should always use quality wire and solder all connections.
An assortment of shrink tube insulation is always handy too. Now we are ready to
solder the ESC to the motor. But first we will need to set up the batteries
because we will want to check out the radio system and ESC to determine the
correct motor rotation.
Batteries and
Connectors plus a short course on soldering
We use the 600 mah 8 cell
packs with our planes because they work well with S400 motors and are small so
they fit well in the smaller planes. The term “mah” refers to the power capacity
of a battery in milliamp hours. So a 600mah battery will deliver its voltage at
a rate of 600 milliamps for one hour (at least that’s how I understand it).
Simply put, the larger the number, the more capacity the battery has, the longer
the plane will run.
The first thing to do is
install the Sermos connectors to the battery packs and
the ESC. Sermos come in packs of two red and two black shells and four metal
connectors. The connectors solder onto the wires and then the plastic shells
snap over them. Always use the red for positive and the black for negative. You
will need to make a pigtail for your charger with a set of Sermos connectors
also. We use Sermos because they are capable of handling lots of power and easy
to plug in. They can also be a pain in the neck if you don’t know how to put
them together. So study the pictures carefully and that should clear things up.
It is recommended to solder the connectors onto the battery and ESC leads.
To begin soldering, strip
the wire back about 3/8 inch and twist the wire as tight as possible. Tin the
wire with solder. Tinning is the process of soaking a wire or terminal with
fresh solder before actually soldering the connection. I use a 30 watt pencil
iron and good grade electronic Rosin core solder. To make the solder flow into
the wire or onto a solder lug, always use enough heat to melt the solder when it
is touched to the part being soldered – not just the tip of the iron. To get
good heat transfer from the tip of the iron to the part, sand or file the pencil
tip quickly and lightly to clean the burnt crud off it and immediately flood the
tip with fresh solder. A dirty solder tip will not solder anything efficiently.
Lets solder a Sermos. Set
the metal part of the connector on a piece of wood and slide the tinned battery
wire into the end. Now touch the soldering tip to the flat part of the connector
close to the closed end of the tube that the wire is in. At the same time touch
the solder to the open end that the wire is poking into. When the connector
heats up enough the solder will flow very nicely into the connector. Keep
feeding the solder in until you feel that there is enough to fill the tube and
secure the wire. If you do this correctly, the solder should have only gone
inside the tube so now let it cool and clean the Rosin film off the end of the
connector with lacquer thinner. You are ready to snap the connector inside the
plastic shell. Refer to the drawings but in a nutshell the connector can only go
into the shell one way. Look into the back end of the shell and notice the slot
is off center, now slide the connector onto the shell so the spade of the
connector is on the same level as the slot. In other words, if you are looking
in the back of the plastic shell and the slot is on top – then slide the
connector in with the spade at the top side and the wire tube below it. Push
them in until you hear them click! If you have to, use a tiny screwdriver on the
back of the connector to push them all the way. Make sure the red shell is on
the red wire and the black shell is on the black wire! Sounds obvious, but I’ve
mixed them up before!
Solder a connector to each
battery wire and to the battery side of the ESC and clip on the appropriate
shells and then you can hook the shells together so the battery polarity cannot
be reversed. Notice a tiny wedge along two sides of the plastic shell – these
have a mating indentation on the opposite two sides. You can slide the shells,
black and red, together and if you do it correctly, there is no possible way to
accidentally reverse the polarity to the ESC. There are a couple of combinations
so pick one and be consistent so all your packs can be charged and plugged into
the airplane without having to fiddle with the plug configuration.
Motor, Speed 400
We have used a number of 400
size motors but have settled on ones that have internal noise suppression
capacitors built in. The capacitors are little ceramic disks with two wires
coming from them and they are usually on the inside of the motor and not
visible. Some motors have them soldered on externally and you will find them
connected from each motor terminal to the case and sometimes one between the two
motor terminals. These capacitors are designed to short circuit the radio
frequency waves that motors tend to generate when they are running. It is
possible for electric motors to cause a “glitch” in the radio control system and
if bad enough, can actually crash your plane. So if your plane does some odd
things (I mean even after considering the pilot), check your capacitors and
replace or add some new ones.
Before soldering the wires
to the motor, you should have determined the motor direction. Leave the
prop off the motor and temporarily hook the ESC to the motor with
alligator clip leads or something like that. For this to work you should have a
charged battery handy and have the ESC plugged into the receiver. Check the
drawings on how to plug everything in. The plug with three wires on it (usually
black, red, white) will plug into the throttle channel on the receiver and since
the Sermos are on the ESC and the battery by now, you should be able to plug in
a battery. Some ESC’s have a switch on them also so if nothing happens, try
flipping the switch. Some ESC’s will start the motor if there is no radio signal
and some will kill the motor if no signal so turn on the transmitter and make
sure the throttle lever is all the way down. If the motor starts up with the
stick in the off position, you will need to flip the servo-reversing switch.
Refer to your radio manual to find these.
You should be ready to fly
your electric real soon. So go ahead and skip to the flying section at the end
of this booklet. The next section will cover the installation of the Norvel
engine and Slickmount for you gas guys.
Gas engine setup
We manufacture a cool little engine mount
we call the Slickmount. It simply makes installing a small engine in small plane
a very easy thing. It doesn’t matter what plane you are building, the
installation is basically the same.
TO BE CONTINUED later
Flying tips
I have a few suggestions for
the first time pilot that may help. The first thing to do is check the plane
over carefully. Eyeball the control surfaces to see that when the sticks are in
the neutral position and the trim levers in the middle of their range, the
elevator and rudder are straight and level. Make sure the wing has at least six
rubber bands holding it on and remember to string the antenna all the way out. I
like to poke a little hole in the side of the fuse to run the antenna wire out,
pull it snug and thread it through a hole in the top of the fin letting the
excess dangle behind the plane. Now do your range check. Our T52 glides real
well so if you are certain the balance point is correct (if electric – put the
battery pack in but don’t turn the throttle on), stand in the middle of a grassy
field, take a few quick steps and give a firm toss. Launch it into the wind (but
don’t try it in extremely windy conditions) firmly and level, do not try to
throw it up into the air or you will risk a nasty stall and nose dive. The first
few times you might want to have a friend launch it for you. It might even be
a good idea to take the propeller off and tape something over the front of the
motor to protect the prop shaft from damage – a bottle cap or hunk of scrap
Styrofoam or something like that. If the plane zooms up and stalls it could
be too tail heavy or you may just need to give it a little down elevator trim
(if it does zoom, try to give it a little down elevator with your control, you
can save yourself a crash by being quick on the sticks and leveling it out
before the stall). Try a couple clicks of down trim and launch again. If it
dives to the ground, be ready to pull it up, remember – you are in control!! Try
a few clicks of up trim to correct the dive. Right and left trim is checked the
same way and corrected with a few clicks of trim one way or the other. Keep in
mind though, that with power on, the trims may have to be adjusted again. Some
of our T52 pilots spend some time on a hill and simply glide down and around to
get the feel of flying.
When you are ready to go for
it, knees knocking, fingers shaking, sweat breaking the brow and all, then fire
the motor up and let’s have some fun!
The worst problems new
pilots have are OVER CONTROLLING and getting right and left mixed up when the
plane turns around and is coming at you. When the plane comes at you, there are
two good tricks to help you out. Since the main project the new pilot has when a
plane is coming at him is keeping the wings level at all cost, the easiest thing
to do is simply move the stick toward the LOW wing. This will immediately right
the plane -- then worry about turning after the plane is past you and going
away. Another technique is to sort of turn your body and transmitter around part
way in the direction the plane is going. Keep your eyes on the plane of course.
This tricks your brain into thinking the controls are actually working
correctly, because they are. Over controlling is the other real big hurdle we
all had to get over. If you watch an RC pilot who has been flying awhile, you
will notice that in typical flight he will move the sticks, most of the time,
very slightly. The only time you really slam the sticks is in the middle of
maneuvers – intentional or non-intentional ones. A very common mistake is to
panic if the plane starts to go down and yank the stick back only to do a loop
or cause a stall and then realizing your mistake, but slightly too late, you
then push the stick forward – but the plane is already in the beginning of a
nose dive – well, you know the picture. We’ve all been there. So what I suggest
when teaching a new pilot is to not ever move a stick and just hold it there.
Make turns or elevation changes in increments by blipping the sticks and letting
them return to neutral. It looks rather jerky, but it will smooth out as you get
the hang of it. If you trim the T52 properly so that it is in a very slight
climbing mode with no stick inputs, then you should only need to worry about
moving the stick right or left for turns with very little up or down
elevator.
Another common mistake new
pilots have is letting the plane get too far away for fear of the turn. That’s
why I suggest blipping the sticks. Do that often so that the plane is almost
constantly turning. This way it will never get too far away. After you relax a
bit you can let it go further but be careful because they get small very quickly
and it is hard to see well enough to bring it back safely. If you do get in that
situation, you will be flying more by what you did last with the sticks than
what you can see because you simply can’t tell if it is coming or going. If you
can’t tell if it is going, one way to check is to wiggle the rudder stick and if
the plane moves right with right stick than it is going away, if the plane moves
the opposite direction than it is coming towards you.
After you get accustomed to
flying and how the plane handles, you would probably like to look like you know
what your doing instead of flying herky jerky through the sky. To do this you
have to understand a little bit of physics and what causes a plane to turn. To
turn a plane smoothly it has to “bank” or the wings have to tip a little, or a
lot depending how fast it’s going or how sharp you want to turn. You can’t
simply bank most planes and expect them to come on around. When a plane is
flying level and straight, all the forces acting on it are in balance. When the
plane is banked, either by the rudder as in the T52, or the ailerons on other
planes, the balance will be upset. Something else has to happen and fast or the
ship will make a really pretty arc right into the ground. As the wings are
tipped, they start to loose lift so to counter that we have to feed some UP
elevator as the wings are tipping. Too much up and the plane will do some kind
of awkward loop, too little and it will do a funny barrel roll into the ground.
Real funny, yeah right! So it has to come from practice and experience but as
you get confident try banking the plane and simultaneously pulling a little up
elevator – not too much – and see what happens. If you fly by jerks, you will
still have to occasionally correct the general downward trend with a little up
elevator, but when you find out what your planes characteristics are you can
start mixing the controls and your flying will improve along with your self
esteem, ‘cause hey, we all want to look good out there you know.
Another little tip, if you
get yourself in trouble and it looks like the plane is going down, you can
sometimes save the day by pulling back hard on the stick quickly then letting it
go precisely at the moment it looks to you like it is going up again or at least
leveling out. Even if it comes out of the dive in a turn, we can work with that.
Just concentrate on getting the ship level and remember boys and girls, if it’s
coming at you what do you do?!? Move the stick toward the low wing and it will
level right out. Good, you’ve got it!!
OK, all good things have to
come to and end and if you’re in the air, you know you will have to come down
eventually. So what now? If you have throttle you can throttle back and circle
the field in lower and lower circles until you feel you can chop the throttle
and let it settle in. Go easy on the elevator and don’t push the nose down or
pull up drastically. Let the air speed set the plane down if you can. Beginners
tend to underestimate the length of field it takes to land a plane and you might
find your T52 heading right for Aunt Gerties’ Lincoln Town Car. In that case a
healthy dose of down elevator should shorten the landing approach considerably.
I would recommend sucking it up and taking the damage to plane over the car.
Though I guess it would depend on Aunties attitude. That’s one of those snap
decisions we’re all faced with from time to time. Good luck!
If you are like most of us,
you never know when to quit, so you will probably run the plane out of gas at
about 500 feet. What to do? Welcome to glider world. The T52 is basically a
glider anyway so no sweat. Just remember – air speed and altitude. Say it with
me --- “a i r s p e e d a n d
a l t i t u d e” . If you have
enough of one or both you can glide anything, but loose one without enough of
the other and you will be looking at a spot landing. So Keep the nose from going
up too drastically to prevent a stall and you might need some airspeed to turn
the T52, so if your rudder isn’t responding you will have to put it in a shallow
dive to make the rudder come alive again. When you strike a balance between lift
and descent, you can smoothly circle the field until it settles in.
Well, I hope this has been
helpful, I hope to keep adding to this little paper as new things are called to
my attention and if there are other areas that anyone thinks should be covered
be sure to drop an e-mail and I see if it can be added.
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Hanger