This is version (V.1.3) June 2003. All of the following is
my personal opinion, hearsay and guesses so I'm NOT responsible for anything.
Legal BS:
The author is in no way responsible or any or all incidental and consequential damages or incidents arising from the use of information contained within or influenced by this Novice FAQ.
SAFETY
First a word about safety. RC Helicopters are not toys.
They are highly advanced, precision machines that have the potential for causing
serious injury or death. Never loose respect for your heli and always be concious
of the devastating effect a mishap may cause. Rotor Blade tip speeds routinely
exceed 250 mph and a 10 lb heli traveling at 70 mph has a enormous kinetic
energy that is released at the point of impact. People have been killed and
maimed so please fly responsible and remember to keep your and the spectators
welfare in mind.
INTRODUCTION RC
Helicopters have been defined as 1000 very expensive flying parts desperately
trying to get away from each other. They are probably the hardest of the RC
flying models to master. It may take months to become proficient in hover
and years to become an accomplished aerobatics pilot. However the rewards
are great. Few other models offer the diversity and challenge a helicopter
provides. It is not a hobby for the inept or frugal, helis do not tolerate
mistakes or cheapskates. Everything must work perfectly in harmony to enable
a helicopter to beat the air into submission. Forces are delicately balanced.
Unlike an aircraft which will do it's utmost to continue flying despite the
pilots attempts to control it, a heli is inherently unstable and it is a constant
battle to keep all forces in eliquium. Observe the controls when an accomplished
pilot is hovering and you will notice constant minor adjustments to the sticks
although the heli seems to hold rock solid in mid air. This comes after many
hours of diligent practice after which corrections become natural like balancing
a bicycle. The heli pilot is also part engineer, scientist and physicist.
Do you have to know exactly how everything works? No, but to notice and troubleshoot
problems one must first know how it's supposed to behave. It helps to build
the heli from a kit to understand the assembly, ARF kits and preassembled
used helis should be taken down and reassembled. Enjoy the challenge.
THE FIRST THINGS TO DO:
Read all the books, magazines and web pages
There is an incredible amount of information available that will answer
most if not all of your questions. Read Schluters 'Heli Manual' for a comprehensive
history on the development of the RC heli in Germany. Paul Tratelius' book
'The Basics Of RC Helicopters' is excellent for answering many fundamental
questions. 'Ray's Complete Helicopter Manual' is an invaluable reference
going into many technical details and concepts. There are at least 30 web
pages at any given time dealing with RC helis and 100s more with airplanes.
Visit them all and bookmark them for later review. See the
Links page for a small list or go to http://towerhobbies.com and look
at their Links page.
Learn the Language.
Dealing with a complicated mechanical / electronic device like a RC Helicopter
requires a understanding of basic physics, aerodynamics and mechanical principles.
By necessity specialist terms are used in the construction and flying of
aircraft and helicopters. You can pick up many concepts just by reading
the books, mags and web pages. Do not be afraid to ask for clarification
on something like an 'adjustable swashplate phase timing anti-rotation link.'
Visit the local hobby shop and flying club.
Local heli pilots will be an invaluable help in initial flight setup and
adjustment. It is extremely difficult to correctly setup a first helicopter
without expert assistance since there is no baseline reference for the novice
to draw on. Local pilots can help select the most appropriate heli / engine
/ radio combo and help guide the beginner through the initial steps. Do
not be afraid to ask even the world champion pilots questions, there is
no heli pilot that is not proud of their machine and would not talk your
head off if given the opportunity. As Curtis Youngblood once said: "I like
simple questions, usually I can answer them". Just don't try to talk while
they're in the middle of their 3d routine. If possible try and buy your
helicopter and parts locally. It might be a bit more expensive but it supports
the struggling local hobby shops. Also the salesperson / owner will gratefully
help with any questions and can set up local contacts. In addition, local
pilots or shops might have used equipment for sale that can save you hundreds
of dollars.
Go to a Helicopter Fun Fly.
There are many gatherings of Helicopter enthusiasts all over the US and
in many other countries. Over a 1000 helicopters in national gatherings,
these fly ins are an experience not to be missed. You don't have to fly,
just look around and take lots of pictures and ask questions. Most helicopters
ever made are usually available for close inspection and flight reports.
Aerobatic routines, scale fly bys, beginner clinics and great raffle prices
(helicopter kits, engines and radios at bigger fly ins) will all be vying
for your attention. Most clubs require that you join the AMA. Mainly for
the liability insurance but there are other benefits of belonging to a national
group. It's about U$58 a year including a magazing subscription.
Buy a Simulator A sim like the
NHP, FMS or Realflight2 is a important training aid. For under U$200 it
is possible to explore heli flight without the investment and risk of actually
flying a model. The good ones like NHP and RealFlight 2 use your computer
radio's trainer jack so all the fancy programming functions are available.
Also the feel is the same since the actual transmitter is used in the sim.
If you don't like helicopters, the sim can be sold at a minimal loss. U$200
seems like a large amount of money to spend on a simple computer program,
but after preventing two crashes with the real model, the outlay is pretty
much recouped. See the Avionics Page for screen
shots and revues of several Sims.
REQUIRED STUFF TO FLY RC HELIS
The Helicopter
Which one to get? Discounting
Electrics and Gasoline powered models, there are 3 general sizes classified
according to engine displacement. The 30, 50, 60 and 90 size are identified
by the size of their glow engines. Increasing with size is the complexity
and cost of the initial kit, repair parts and operating expenses. Each size
has its advantages and drawbacks. A 30 size plastic framed heli costs less
to own, has an inherent ruggedness and is generally easy to maintain and
setup. However it is more affected by wind gusts and is harder to see at
a distance. Still, a basic 30 model is the preferred trainer. Top of the
line aerobatic 30s can rival a 60 in cost but posses a flight capability
equal to all but the most expensive 60 size competition helicopters. A 60
or 90 size heli is more stable in windy conditions, easier to see at a distance
and possesses an unmatched power to weight ratio. Besides the more expensive
initial heli kit, consideration should also be given to the higher cost
of the bigger engine, repair parts, fuel and the required high quality servos.
The 50 size was introduced to bridge the gap between the basic 30s and the
high performance 60s. Today 50's fall between the two with aerobatic capabilities
to rival competition 60s and a lower operating cost due to smaller components.
In the end a selection of a helicopter familiar to local pilots will greatly
facilitate obtaining assistance. Most any 30, 50 or 60 can be setup to make
an excellent trainer. 30 size helis are also less intimitating and many
pilots like to fly their less expensive small boys while giving their U$3000
contest machines a rest. Electrics are an emerging field which has shown
increased popularity due to recent advances in battery and motor development.
However electric helis are build very light and are therefore fragile and
their run times on a battery charge is around 5 minutes. This short flight
time and fragility do not make a recommended helicopter for training. Gasoline
(Petrol) helicopters can make fine trainers but are usually advanced kits
which require some experience in building. They do have the advantage of
requiring less starting equipment, a lower fuel cost and minimal smoke and
oil spray during flight.
Ease of Building / Setup
If there are no local pilots or they fly every imaginable brand, an important
criteria for new pilots should be the ease of assembly and setup of the
helicopter. Kits from different manufactures vary widely in their quality,
assembly ease, depth of instructions and configuration. Some kits simply
bolt together and fly adequately. Others require serious time in adjustment,
maintenance and setup but reward the owner with superior flight performance.
High maintenance / build time helis include X-Cell, Intrepid and Vigor.
Raptor, Venture, Caliper, Sceado, Shuttle and Hawk are simpler and easier
for a beginner to conquer.
Parts availability / Prices
Nothing is worse than sitting out perfect flying days waiting for a 95 cent
part that is backordered 2 months. A local hobby shop (if there is one)
may only stock parts for one type of heli so support for your model might
depend on mail order. Availability is less of a concern for popular models
such as the X-Cell, Raptor, Sceado, Freya and Shuttle series. Major importers
for them strive to keep all parts in stock at all times. Other helis such
as Century (2 places for parts), DHNP, Vario and Robbe might have a harder
time finding replacement parts. Available parts mean nothing if they are
unaffordable. Some heli spares carry a criminally high price tag while for
others the same part costs half as much. Pricing is pretty arbitrary with
some 60 size parts cheaper than the 30 size counterparts, but owners of
exotic European or competition machines can expect to pay for their exclusive
name tag. Aftermarket parts by reputable manufacturers or used items from
other pilots can sometimes lower replacement costs considerably.
Survivability / Maintainability
Ruggedness and the ability to survive the hard use of a Novice are important
for any heli used in the initial stages of learning. Plastic framed helicopters
have a fair amount of flexibility which allows them to rebound from impacts.
Aluminum frames tend to bent but can be straightened with some effort if
not overstressed and cracked. Carbon fiber and G10 frames have a high rigidity
and limited flex and either return to their original shape or break cleanly.
Plastics framed helis like the Raptor, Shuttle and Hawk are the preferred
configuration. Other frame materials may offer better structural integrity
but will cost more to repair more often. Maintenance requirements and ease
of access vary widely between manufacturers. Simple 30 size helis run for
many flights with only a modicum of upkeep like oiling bearings, cleaning
off dust and grit and replacement of high wear items. Others like the X-Cell
need constant love and attention to maintain their peak efficiency. Just
like a race car Vs the family car, high performance comes at a price.
Flying Characteristics
There is no such thing as a dedicated trainer helicopter. All helicopters
in production today from the smallest to the biggest have flight capabilities
only explored by the worlds top 3D aerobatics pilots. A helis' setup however
can be altered to provide the characteristics and response tailored to a
beginning flyer. A flatter Pitch range, smoother tail rotor response, limited
throttle curves and the addition of bigger training gear can make even the
highest performance helicopter into a docile hovering trainer. Most heli
models are designed to cater to a wide variety of flying styles from gentle
hovering to wild 3d aerobatics. Specialist models made for FAI precision
flight or purely 3D freestyle are of extremely high quality with a corresponding
astronomical pricetag.
Good Starter Helis - in order of preference: 30 size - Thunder Tiger Raptor V2, Hirobo Sceadu, Century
Hawk SE. 50 size - Hirobo Sceadu 50, Raptor 50V2, Century Falcon SE. 60 size - Hirobo Freya, Raptor 60 V2, XCell Fury.
Heli Dictionary and Parts Diagram
Much terminology is used in both full scale and model helicopter design and
the novice can quickly become overwhelmed by the many strange descriptions
and names. Below is a diagram of an Intrepid 60 size glow powered helicopter
with the main parts labeled. Following is a short list of terms and definitions.
Swashplate - stationary lower part and rotating upper part allows servos
to change main blade and flybar paddle pitch.
Anti-Rotation Link - keeps lower part of swashplate from turning. Aileron
/ Elevator interaction / timing can be adjusted on some models.
Mixing Levers - move the main blade pitch and flybar paddle pitch. Have
different ratios depending on style of flying.
Flybar - stabilizes the main rotor disk. Length, paddle size and weight
affect the cyclic response of the heli. Heavy / small paddles give mellower
response.
Flybar Paddle - assists in changing main blade pitch. Size and weight
affects aeropatic ability and steadyness in hover.
Main Rotor Blade - generates lift to allow the heli to fly, made out
of wood, fiberglass, kevlar, aluminum or carbon fiber. Length varies with
helicopter size.
Main Rotor Blade Grips - hold the mainblades and contain up to 3 sets
of bearings. Made of fiberfilled plastic or aluminum.
Main Rotor Head - metal or plastic headblock contains bearings and seesaw
for flybar, spindle(s) to retain main blade holders and dampening system
for main rotor blades.
Tail Rotor - opposes the torque reaction from the main blades. Driven
by wire, belt or tube. Blades vary in length with helicopter size.
Tail Rotor Gear Box - driven by main gear, contains gears to drive tail
rotor hub and blades.
Clutch - allows engine to idle without driving main and tail blades.
Clutch engages at higher engine rpms.
Clutch Bell - aluminum, steel or plastic bell, has interior lining to
allow clutch to engage at higher engine rpms.
Cooling Fan - fan attached to engine blows cooling air over the engine
cylinder head. Made of plastic or aluminum.
Cooling Shroud - directs airflow from cooling fan over the engine cylinder
head fins. Made of plastic.
Main Gear - driven by pinion gear on clutch bell. Reduction is around
9:1. Has teeth on top for use by tail rotor pinion gear pickup. Autorotation
bearing is in center of gear. Made of fiberfilled plastic.
Tail Boom - hollow tube of varying length, contains tail rotor drive
wire/belt/tube on the inside and the tailrotor control rod on the outside.
Made of aluminum or carbon fiber.
Tail Boom Support Struts - increase rigidness and prevent some resonant
vibrations of the tail boom.
Tailrotor Control Rod - metal rod running from the tail rotor servo
to the tail rotor gear box and changes the pitch of the tail blades to
yaw the helicopter.
Landing Gear - supports heli on ground. Made of plastic and / or aluminum.
Width and size vary by helicopter.
Servo Tray - frame to which the electronic components such as servos,
gyro, battery and receiver are attached with screws, zipties, rubber bands
or velcro.
Engine - internal combustion engine either 2 or 4 stroke. Burns either
glowfuel, gasoline or methanol. Size varies with heli.
Main Fuel Tank - semiclear plastic tank holding fuel for the engine.
Comes in 6 to 20oz capacity depending on heli size.
Horizontal / Vertical Fin - help to stabilize the helicopter in forward
flight. Often removed for hardcore 3D aerobatics to reduce drag.
The Radio System
Computer Radios
This is a area where the most expensive radio set affordable should be
considered. Inexpensive radios without computer programming, while perfectly
useable, are outgrown within months. A high quality, versatile radio will
make flying a heli much easier and more enjoyable. Computer programmable
radios like the Futaba 6XH or the JR642 should be the absolute minimum
investment. The Airtronics R8000S is the best of the low-end
radios. The Futaba 9CHx and the JR9Z give the most bang for the buck and
will serve for many years well into competitive flight. The debate of
FM (PPM) Vs PCM continues to rage. PCM, or Pulse Coded Modulation, Transmitters
encode the radio signal into digital form and the receiver reconverts
it. It has the advantage of slightly better interference rejection and
the Fail-safe function. PCM Fail-safe will move the servos to a preselected
position so in case of radio link loss the throttle can be moved to idle
resulting in a reduction of crash damage and preventing a runaway helicopter
from injuring pilots and spectators. Downside is that PCM masks small
glitches that can alert the pilot of impending radio failure. Both FM
and PCM work fine in all helicopters with the exception of gasoline powered
ones where PCM is recommended to prevent ignition source interference.
PCM radios carry a higher pricetag mostly due to the higher quality servos
and computerized receiver bundled in the set. The difference in Aircraft
and Helicopter radio models is some switch positions on the transmitter,
better servos and a bigger battery in the heli version. Most computer
radios hold airplane, glider and helicopter software and are switchable
between these modes.
Radio Selection - in order of preference:
Here are some good choices in computer helicopter radios: Basic: Airtronics R8000, JR 6012, Futaba 7C, Hitec Eclipse Middle: Futaba 9CHx, JR 8131 or 9Z/NL> Advanced: Futaba 9ZHW(S), Futaba 14MZ, JR10SXII
Servo Selection
Here are some good choices in Servos in order of preference: Budget (30): Hitec 545,Futaba 3001, JR 517, 811 Best (30/50/60): Futaba 9202, JR4131, AIRTRONICS 94735
Expensive (30/50/60): JR or Futaba Digitals, JR4000, Futaba 9402
The Gyro
What is it? A gyro
is a yaw rate dampening device which prevents any uncommanded sudden movements
by the tail. While it is possible to fly a heli without a gyro it is definitely
not recommended to learn without one. Gyros try to hold the tail in a steady
position by sensing any yaw movement and then applying a counter command
to the rudder servo. There are now two major groups of gyros. The 'Conventional'
gyros which include both mechanical and piezo versions and dampen the yaw
axis. The other is the 'Heading Hold' kind. In HH mode the gyro will not
only dampen the yaw but also return the tail to the previous position in
effect keeping the helicopter pointed in one direction regartless of wind,
torque changes and flight direction. In this mode the tail must be flown
constantly since the heli will not weather vane and straighten out in the
direction of flight. HH gyros are suberb for backwards and heavy 3D flight.
Beginners also benefit since the tail will not swing around when learning
to hover. The pilot has control over the rudder servo by overriding the
gyro signals with stick input. There are programming setups for computer
radios which provide for exponential, linear or rudder stick dependend amount
of the tail rotor servo arm deflection. Gyro gain is the amount of dampening
the gyro applies to the t/r servo. It is most often maximized for hovering
maneuvers and reduced for aerobatic forward flight. The amount of maximum
gain possible is depended on the speed of the rudder servo and the amount
of slop in the tail rotor control linkage. A high speed servo (Futaba 9253
or JR8700G) is highly recommended as slower servos are not able to keep
up with the speed of corrections the gyro outputs. This is displayed by
a condition known as tail wag when the tail wags back and forth at high
gyro gain. Lowering the gain, installing a higher speed servo and eliminating
slop in the t/r control linkage reduces this event to a minimum. Correct
installation and setup of the gyro is very important as flights with reversed
gyros or tail rotor servos tend to be over within seconds.
Piezo or Mechanical
A mechanical gyro uses deflection in small motor driven flywheels to sense
the yaw movement. A sensor detects the movement of the flywheels which are
centered by two small springs. In a piezo gyro a suspended piezo-electric
crystal develops a error voltage as yaw movement excerts a force on the
sensor. There are no moving parts to wear out and a resistance of 300g to
impacts is claimed. Sophisticated software is used to optimize the holding
power around center. Heading Hold gyros use software to hold the tail on
a preselected heading. There used to be a big price difference between electro-mechanical
and piezo gyros. Now with prices much closer there really is no reason to
settle for a mechanical unit. Piezos have a much lower current consumption
(10ma Vs 300ma) giving longer flights, never wear out, have better performance
and are able to survive a crash that would destroy a unit with moving parts.
Gyro Selections
Here are recommended Heading Hold gyros: Futaba GY-401 HH piezo with 9253 servo (U$ 200) Futaba GY-502 HH with 9253 servo (U$ 275) CSM ICG540 Heading Hold piezo (U$ 220 approx.) Futaba GY-601 with special servo 9151(U$350) JR 5000 with JR8700 servo (U$400)
Here are Conventional Gyros: Generic Piezo (Century PG-01) (U$ 99) Futaba 501 piezo (U$ 340) JR 3000 piezo (U$ 375) JR 1000/900 piezo (U$ 275/250)
The Engine
Description Most model
engines are of the glow fuel powered, 2 stroke internal combustion type.
Oil for lubrication and cooling is carried within the fuel at about 16 to
25% of main volume. The oil is either synthetic, castor or a blend of both.
Synthetic oil does not leave a brown residue when burning but castor has
slightly better high temperature characteristics. Ignition is provided by
a Glow Plug which has a wire coil that is initially heated by a starting
battery. Once the engine is running, the chemical reaction between the fuel
and noble metals in the plug maintains a coil temperature high enough for
ignition. The fuel is mixed in a carburetor which has (usually) two needles
for adjustment of low speed and high speed mixture. The correct mixture
adjustment is critical to the proper operation of the engine. Too rich a
mixture can result in hard starting, low power and the bogging down of engine
rpm during max. power usage. A lean mixture results in overheating with
possible loss of the glow plug or major engine components as well as a slow
decrease in available power. Four stroke engines use 4 strokes for one power
cycle and use intake and exhaust valves similar to a car engine. They run
quieter, are more fuel efficient and produce high torque at lower rpm so
heli gearing must be changed to accommodate the differences. There are several
helis that use 4 stroke engines but higher maintenance and higher engine
cost has limited the spread of these types. Gasoline weedeater type engines
are available on several 60 size models. Low fuel cost, no oil waste or
smoke and less support equipment are attractive benefits from this type.
Special synthetic Oil in the ratio of 20 to 1 is mixed with regular gasoline
making for a very low fuel operating cost. While heavier and more complicated
than glow engines, gasoline burners are a good choice where glow fuel is
expensive or not available.
Reliability
In a helicopter engine reliability is everything. A aircraft engine failure
might be an annoyance followed by gliding to the ground but in a helicopter
engine failure is often followed by catastrophe. Most heli engines today
display impressive reliability and quality of construction. Major manufactures
like OS, YS, Enya, Webra etc have refined their construction and design
to the point where out of the box performance is more than adequate. Higher
performance and competition engines are by their nature more finicky and
present problems to new comers without extensive engine tuning experience.
Ease of use
I really hate it when I spend all day at the field cussing at the engine
vice cussing at my inaptitude in flying. If it doesn't run it's a paperweight.
If you are tempted to save a few dollars and go with a 'lesser known' brand
remember that you get what you pay for. In the end the more expensive and
better engine is ordered anyway. Seek out the assistance of experienced
flyers and engine tuners for purchasing the engine for your heli.
Fuel, Plugs, Exhaust Glow
fuel is a mix of about 16-24% oil - synthetic or castor, 0-30% nitromethane
with the balance methanol. It is extremely poisonous and flammable and should
be handled with care. The nitromethane in the fuel provides an increase
in power and burn temperature albeit at a higher cost. Fuel selection is
often dictated by local conditions. North American flyers enjoy a much lower
cost for high nitro fuels at about U$20 per gallon for 30% nitro fuel and
subsequently engines for this market are designed for running on a high
percentage (10 to 30%) nitromethane. In European and Asian markets fuel
costs range up to U$100 for a gallon of 15% nitro fuel and so engines in
these areas are tuned to use as little nitro as possible. For US pilots,
15% nitro, synthetic oil fuel is the basic stable for heli engines. Popular
US fuel brands include CoolPower (synthetic), Omega (castor blend), PowerMaster
and Wildcat.
To ignite the fuel the glowplug maintains a high enough temp for ignition
by a chemical reaction with the glow fuel after the ignition battery has
been removed. Plugs come in different heat ranges from cold to very hot.
Most reliable and consistent plugs have been identified as the Enya#3 and
the OS#8. While these plugs are more expensive than others, the reliability
and increase in service life more than makes up for the initial outlay.
The exhaust is an important part of the power package. They fall into two
general kinds: muffler and tuned pipe. A muffler is a canister, sometimes
with internal baffles for reducing noise, that allows expansion of the exhaust
gasses prior to venting them into the air. Tuned pipes are setup to a specific
length so the pressure waves from the engine exhaust are reflected back
to the cylinder causing a kind of supercharging effect for increased engine
power. Pipes are used mostly with lower nitro fuels to compensate for the
lower power output. Pipes have to be set up very carefully and mixture settings
on the engine carb are somewhat critical. It is therefore recommended to
stick with mufflers for a much easier time in tuning the engine.
Popular Engine Selections and Mufflers/Pipes in order of preferece: For 30s: OS37SX, Webra 32, TT39 - Any can muffler, Hatori, Helimax or
Genesis Pipe . For 50s: OS50SXH, TT50, Webra 50 - Hatori SB5 muffler, Century 3033X
muffler, Curtis Muscle Pipe 1. For 60s: YS61SH2, OS61SXWC, TT70PRO - Hatori 666 style muffler, X-Cell
Nitro Pipe muffler, Curtis Muscle Pipe 1. For 90s: YS80STH, YS91STH, OS91SXH SE, Webra90 - Special Hatori or KSJ mufflers, Curtis Muscle Pipe 2.
The Price to Pay
Initial Investment
At first glance the price for starting into RC Heli flying is comparable
to starting with a trainer aircraft. However, helicopters require additional
accessories and equipment that can raise the capital outlay at an exponential
rate. For some reason manufacturers and retailers seem to think that just
because you fly a helicopter you have much more free capital to spend on
that machine. Helicopter specific parts carry a higher pricetag than comparable
items for aircraft use. Lets look at the initial damage to your wallet for
a basic, beginner helicopter setup:
The helicopter itself is from U$ 200 to U$400.
The engine and muffler U$ 150 to U$ 250.
Radio control set U$ 250 to U$ 500.
Piezo gyro U$ 150 to U$ 200.
Ground support equipment (starter with battery & charger, glowdriver with
charger, fuel and pump, pitch gage, oil, grease etc) U$ 120 to U$ 200.
Metric tools (Allen wrench set, phillips and straightslot screwdrivers,
pliers, socket set, plug wrench, ball link pliers, tool box etc) U$ 75 to
U$ 100.
Misc. Items (beer for instructor, bandaids, spare parts [main blades, tailblades,
mainshaft, spindles, gears, tailboom], sunblock etc) U$ 50 to U$ 100.
Computer Simulator U$ 200
This is a complete setup to get this thing into the air. Total cost
if starting from scratch is about U$ 1000. You can save mucho $ if the
local club or other pilots have used equipment for sale.
Upgrades
There are upgrades available for all helicopters on the market today. Some
kits really do need some additional parts to make them easier to fly but
for the most part a well constructed kit will fly out of the box without
expen$ive add on items. Many upgrades come in shiny colors such as MinAirs
Gold parts, T&T blue and purple or Zeal yellow. For a pilot learning to
hover few if any add-ons will make the heli fly any differently. You can
reduce the cost of upgrade parts, such as a metal swashplate by waiting
until the original plastic unit is worn and then replacing it with the more
expensive, reliable and accurate part. Most upgrades are bought more for
the mental peace of mind than for actual performance increase. A tricked
out heli with all available upgrades incorporated may be more than double
the cost of the original baseline kit. Example is the XCell 30/40 and the
XCell 46 Graphite. Essentially the same machine, the 46G has allmost all
the fancy upgrades and so costs U$ 680 vice the basic XC30s U$ 360. Of course
the 46G is now much more precise and pretty but a beginner would hardly
notice the difference in identically setup machines. So save some cash in
the beginning, spend it on the radio and fuel and as parts wear out replace
them with quality upgrades.
GROUND SUPPORT EQUIPMENT AND TOOLS
Required Tools (all metric) and Accessories
Allen wrenches or drivers - the expensive hardened type at U$15 each
in 1.5m, 2mm, 2.5mm and 3mm.
Nut Drivers, 1/4 in socket set, open end wrenches
Needle Nose Pliers and Diagonal Cutting (Dikes) pliers or Leatherman
type multi tool
X-acto knife, scissors, tweezers.
No1 and 2 Phillips, No1 and 2 straight screwdrivers. Note that Japanese
helis use JIS type Phillips screws which are different than US Phillips.
Pitch Gauge, Blade balancer if building wood blades, Dubro HiPoint Balancer,
ESV volt meter.
Alcohol/Paint thinner, blue loctite, Teflon grease, Teflon oil.
Fuel filters, silicone fuel line, fuel shutoff clips, foam for radio,
glow driver for plug, fuel pump and fuel, electric starter with appropriate
adapter, 12v battery for starter, battery chargers.
CA superglue, epoxy, goop/PFM/Zap-A-Dap-A-Goo.
Training gear made of 2 crossed wood sticks with 4 balls on the end
of the sticks, rubber bands for skit mounting.
Optional Tools and Accessories
Velcro strips, zip ties, twist ties.
Balllink pliers, hemostats, big sledgehammer.
Battery Charger/Cycler, LED battery level meter, field quick charger
Skytach, prop tach, Dremel Tool with access. kit.
Cell phone, ice water, first aid kit, spare helicopters
Learning to Fly
There is one fundamental rules that are almost universally accepted:
1: Get an experienced heli pilot for the first flight.
2: If there is no local pilots available see rule #1 and travel.
Setting Up
Setting up is done at home after the heli construction is completed. Do
not try this at the field with a Swiss army knife. Feeding an experienced
heli pilot at your place is a good way to obtain help. Following the instructions
included by the manufacturer is not a bad starting point. For learning to
hover a pitch / throttle setup for advanced aerobatic flight is not recommended.
Initial flights are done in the Normal mode so Idle Ups should be disabled.
This will setup most Computer Helicopter Radios with Hover at 3/4 stick
and inverted hover at 1/4 stick. I have a Futaba 8UHP so the following is
mostly based on the 8UHP menus but is applicable to all computer sets.
Novice Flyers should disable the Idle-Up 1 and Idle-Up 2 flight modes until
ready for fwd flight.
The top of flight curve is 100% or +10 deg. That way the flight pitch range setup is linear
with equal travel of all servo horns, bellcranks, mixers etc around that
50% 0 deg point.
Mechanical adjustment of the tailrotor control rod is required at first
flight. Important - refer to the gyro instructions for any deviations
to this procedure.
A large open area, preferably with short, soft grass is required at this
point. The site could be a soccer or football field, an empty parking
lot or ideally the local flying field. It is imperative that spectators
maintain a safe distance of at least 100m/yrds. Asphalt or concrete lots
are fine but any damage is multiplied by the unyielding nature of the
surface. With the engine running gently increase throttle to make the
heli light on the gear but do not lift off. At a safe distance look at
the mainblades and adjust their tracking by either raising the pitch of
the lower or reducing pitch on the higher by adjusting the head linkage.
Trimming for stable Hover
Any fall will not hurt the heli, only the sudden stop at the bottom. A experienced
pilot is invaluable at this stage to assist in this part. For first hover
strictly observe a height limit of 6in (30cm). At 6in with training gear
it is very hard to damage the heli even if it goes totally out of control.
Stand at the left or right rear of the heli at about 5m/yrds distance for
a partial side view. Increase throttle/collective until the heli just clears
the ground. Note any tendencies for the heli to move fwd, back, left, right
or if the nose swings clockwise or counterclockwise. After about 1 second
land the heli and adjust the trim on the tx to counteract the observed drift
tendencies. Note that the tailrotor blows air to one side so the heli must
lean in the same direction to counter the airflow pushing effect. Do this
several times until the heli stays fairly stable in one place. Shut the
heli down and mechanically adjust the pushrods to return the tx trims to
center. Continue these bunny hops, increasing hover time at 1 second intervals.
Do not get discouraged or impatient as even the world champion pilots started
out this way. Overconfidence or impatience can result in vast bills and
lots of practice on reassembling new parts. At this time also observe the
engine to spot any lean/overheating or too rich/4 cycle operation, too rich
is better than too lean.
Hovering Exercises
Once a full tank can be hovered in one place at BOTH the right and left
side begins the time for basic flight excercises.
In a hover at 6 to 12 in, move the heli between the right and left
hover positions, landing and taking off each time. Then hover over each
landing spot and do not touch ground for the entire tank.
Hover either right or left and slowly move fwd a few meters then land.
Take off and move back to the original spot. Then hover fwd and back,
then fwd, left, back, right, fwd in a square going both ways.
Go right/left and try turning the heli a bit in the direction of flight
each time eventually flying by in front of you looking at the heli from
the side.
Learn to hover sideways, both sides. Start by turning your body with
the heli and then gradually turning back to look straight at the side.
Try thinking of Nose Up and Nose Down and Roll In and Roll Out when
looking at the side.
Learn to hover Nose-In. This means relearning hovering from step one.
Throttle/collective still functions as before but the cyclic stick is
reversed. An easy way to remember is to move the stick in the direction
you don't want the heli to go. Tailrotor control still moves the heli
in the same direction as long as it is viewed as clockwise or counterclockwise
rotation vice nose left or right. Stick at 6in altitude and alternate
between nose-in and tail-in to prevent unlearning either one.