June 2009 49
THE HELICOPTER HAS
become one of the most
popular RC interests on the
market because of the
emergence of numerous
affordable and easy-to-build
kits. Many kits are designed
to be set up in a way that
allows beginners to learn and
progress with them as
advanced flying skills are
acquired.
These pilots can fly the
same helicopter from training
gear to 3-D, if they choose,
by making minor mechanical
adjustments or installing a
few upgrades. All the while,
they can fly a machine that is
safe and reliable—as long as
they follow the assembly and
maintenance tips I’m going to
cover.
Regardless of whether it is
a helicopter, airplane, glider, etc., aircraft
need attention before you take them out to
the field—especially if you’re going to a
fun-fly, where many people are either going
to be watching you or flying beside you.
Good maintenance also protects the
investment; some machines out there cost
their owners fairly good amounts of cash.
The modern RC helicopter is much
easier to build, set up, and maintain than
older versions. This is because they have
fewer parts, they self-align during
assembly, and they have factory-balanced
components, which makes the spinning
parts operate more smoothly, causing less
overall stress on the airframe.
by
Andy
Panoncillo
No matter how
complex the
machine, good
maintenance
practices can
ensure the
success of any
project.
06sig2.QXD 4/22/09 10:50 AM Page 49
50 MODEL AVIATION
Ball-link pliers, wire cutters, needle-nose pliers, and c-clip pliers
are just a few essentials of helicopter maintenance.
Some wrenches have special functions other than the obvious. The
Align types have a cavity that can store bolts, nuts, or spare tips.
Above: A simple caliper can make your build or maintenance
easy and accurate. A digital caliper is extremely handy, for
those who don’t mind the extra cost.
Right: Regularly inspect main and tail blades. Insects can load up
quickly on their LEs. Look carefully for nicks and cracks.
Keep the model organized by assigning fueltank
lines specific colors. Zip ties and doublestick
foam tape bind loose items so they don’t
come to harm.
Socket wrenches come in all shapes; these
are good for 30-size and larger helicopters.
Metric sizes from 4mm to 14mm are typically
useful.
Engine service requires a crankshaft
lock or piston lock (foreground).
Correctly tightening the fan/clutch
assembly would be impossible
without one.
Photos by the author
Keeping a good-running starter and battery
prevents hassles at the field when you’re
ready to fly your aircraft. A 4S Li-Poly battery
is used here.
06sig2.QXD 4/22/09 10:51 AM Page 50
June 2009 51
The fact that a helicopter has many moving parts dictates a
degree of fanaticism regarding equipment installation. Neatness
counts and can prevent heartache later.
Whether electric- or glow-powered, a secure canopy will help
streamline the machine and keep equipment as clean as possible.
Left: At midstick on the
transmitter, the swashplate
and lever should be level.
The servo arms should be
set up for equal throw on
each side of the midstick
point.
Right: Some pilots no longer
use a pitch gauge, and it works
for them. I recommend one to
monitor the amount of pitch,
to assure that the mechanics
are within limits.
Above: Keep an eye on the bottom for
excessive wear on struts and skids.
Silicone-rubber bumpers are available to
protect landing gear.
Right: This model’s wiring is mostly
hidden on the inside of the frame. Nice!
Electrics rarely get dirty, but they should
be inspected as frequently as enginepowered
aircraft.
06sig2.QXD 4/22/09 10:18 AM Page 51
Even smaller 400-class machines need regular maintenance. Tug on the ball
links now and then to check for security.
52 MODEL AVIATION
While a helicopter is transported, bouncing can wear on its
mechanics unless a simple blade holder is used.
Whether the helicopter tail control is driven by a belt or torque
tube, make sure that the bearings are properly lubricated and
cleaned to prevent any chance of binding.
A good fuel filter ensures that clean fuel will
get to the engine, prolonging its life and
ensuring that optimal power can be
achieved.
The requirement for special tools to
maintain an RC helicopter is behind us,
but we still need some essential devices to
keep our machines operating well. You
can find these tools in the average flight
box.
Head Assembly: This is where most of
the work happens in terms of setup and
maintenance. That is especially true now
that many head-design assemblies include
programmable linkage features that allow
the sensitivity to be customized to suit a
specific taste or flying style.
A gadget that I fully recommend is a
swashplate leveling tool. Using it the right
way eliminates most problems with a
helicopter’s trimming in terms of control
interaction. Not only will this instrument
indicate a neutral state, but it will also
clearly show when the servos are causing
unwanted input that can often occur in
CCPM (Cyclic/Collective Pitch Mixing)
mechanics.
For instance, if right cyclic also inputs
aft cyclic, this requires the pilot to input
forward control when only roll input is
enacted with movement of the transmitter
gimbal. It’s like flying a model that is
constantly out of trim.
You can purchase a swashplate leveling
tool from a Web site or hobby shop that
06sig2.QXD 4/22/09 10:18 AM Page 52
handles RC helicopters. This device can
be used for the majority of helicopter sizes,
from 30 to 90. If you have a 450-size
model, you’ll need the smallest swashplate
leveler.
Use the leveling tool to identify
interactions on the bench. Adjustments
can be made mechanically or with a
program mix in the radio. Most
interactions can be detected while testing
the collective pitch control; watch the
bubbles as the swashplate moves up and
down.
Off-center indications will identify
early what servo or linkage needs
tweaking. It’s well worth the effort,
because your machine will fly practically
perfect on its first hop.
Ball Links: These are the primary
connection between all of the model’s
mechanics. They should fit securely but
move freely.
A tight link offers security, but its
binding can prevent mechanics from
recentering or operating at their full
potential. A machine with tight links will
eventually break in, but it might be extra
work for the pilot to operate until then.
A ball-link sizing tool will condition
any linkages that are too tight on their ball
ends. Use this instrument sparingly; an
oversized linkage won’t stay attached and
will be less precise and more dangerous to
operate.
Links are inexpensive, so buy a pack and
have it handy for replacement in case a
preflight reveals a faulty area.
Pitch Gauge: With enough experience,
some pilots avoid using a pitch gauge.
They’re either not picky or figure that
flight-testing will reveal any issues and
correct them later.
That’s not the method for me.
Regardless of skill level, the pitch gauge
can offer great information that will help
monitor the amount of pitch in the blades.
This way, I know if the design limits are
exceeded and whether or not the amount of
pitch a specific engine can handle is
delivered.
If your helicopter’s head mechanics are
adjustable (programmable), changes to the
linkage geometry can be gauged with a
measuring tool such as a pitch gauge. Keep
a log of the readings; in the event of a
mishap, the helicopter can be returned to
those settings after the rebuild.
Caliper: A mechanical or digital caliper is
an invaluable tool for building, maintenance,
and/or repair. This device can be used to
ensure equal measurements on multiple
links and identify other points on the
helicopter that need to be equal on each
side.
Calipers are also ideal for identifying
measurements called out in the instruction
manual and for verifying correctness or
deviation of the actual assembly. It takes
out the guesswork.
With the flybar, the rod needs to be
centered within the assembly. A caliper
makes it easy to compare both sides without
having to squint to look at the fine lines of a
precision metric ruler.
Frame: When it comes to frame assembly,
the majority, if not all, of the kits self-align
during assembly. That is extraordinarily
helpful for the experienced pilot who is
working quickly to get a machine back in
the air, and it is especially helpful to the
new pilot who is starting out in this hobby.
Assemble the frame with the main shaft
temporarily installed inside the main
bearings. While tightening the bearingblock
screws, check periodically to make
sure that the shaft freely slips up and down.
A tight fit indicates misalignment or merely
a set of mounting screws that are tightened
more or less than the others; either is easy to
fix.
The essential thing is the servo locations
and proper servo-horn alignment. Assign
and locate servo arms once they have been
neutralized with both transmitter sticks in
the center (throttle at the halfway point).
Follow the instructions and set the servo
arms so that they align with the frame/case
as directed. Servo-arm length is critical as
well, so be diligent. Variations will cause
unwanted control input mixing.
Most servo arms are located with the
arm 90° of the servo case. This directive in
a setup system is commonly referred to as
“The Rule of 90.”
A servo arm and linkage system that is
90° relative to a specific pivot point will
deliver equal throw on either side. All
helicopters demand that equal throw at
least be available for the system’s
mechanics to operate correctly.
Engines: Engine technology has improved
tremendously, and that includes advances
in power, smoother throttle response, and,
thanks to new carburetor designs, more
reliability and stronger fuel-delivery
capabilities. In addition, the power plants
cool better overall, promoting longer life.
However, despite all of this, care is
necessary to keep engines running well. I
recommend a random check on the
mounting bolts or screws, since these
points are subjected to stress and vibration
every time the helicopter is flown.
Another area of the engine you should
inspect is the glow plug. Many of us don’t
change one of these until we learn that it is
no longer working—either during start-up
or, worse, during flight. The latter can be
costly if your machine is in a position
from which it won’t recover gracefully.
Check the glow plug on a regular basis,
and replace it if at all suspect of fault. The
average cost for a good plug is $5. That’s
certainly better than paying for costly
replacement parts.
Helicopter fuel is known to have more
oil and nitromethane content, to promote
better performance and cooling. Our
engines will run on airplane fuel, but they
may not last as long or be as reliable. Why
chance it?
Spending a few extra bucks on the right
fuel will pay you back later. You won’t be
sorry; use “helicopter”-specified fuel.
Tail and Tailboom: Model helicopters
have either a carbon fiber or aluminum
tailboom. Good tailboom supports offer
stability and prevent distortion.
Make sure that your machine’s
tailboom supports are fastened well.
Assemble them with an epoxy such as J.B.
Weld, to prevent the mounting lugs from
separating from the support material.
Include these mounting points during a
routine preflight check or a once-over
after a hard landing. Look for any
fractures or cracks, and make sure that the
tailboom clamps are tightened properly;
don’t overtorque the mounting bolts.
You should also thoroughly inspect the
tail section, since the high speeds at which
the parts operate can create sudden
irregularities when fault occurs. Any
suspect vibration that you see or hear can
quickly cause such problems as drifting
or, worse, total failure and a crash.
The introduction of the open tail
gearbox design greatly helped RC
helicopter pilots with maintenance. It
made points such as the gear mesh much
easier to inspect and adjust if needed.
Open gearboxes don’t require
lubrication, but keep them as clean as
possible to prevent excessive wear. We
need to lubricate areas that have slide
bearings, such as the tail-rotor pitchcontrol
slider.
Regularly inspect any screws and
bolts—particularly setscrews. Where
metal-to-metal contact is made, treat the
machine threads with a thread-locking
compound. Refresh the compound
whenever a screw is retightened or
replaced. It works best on threads that are
free from lubricant.
Keep your helicopter manual handy at all
times. Even when disassembly is done
with the utmost care, reassembly can be
confusing. Having at least a part
explosion illustration is a comfort.
Incorrectly reassembling an assembly can
have disastrous consequences.
Thanks to improvements in materials
and helicopter design, we enjoy flying
more and worrying about our machines
less. They can take more flight
punishment and therefore hold up better in
a mishap.
If we do our part in inspecting and
maintaining our models, fellow RCers—
and especially the public audience—will
appreciate how we respect our hobby/
sport. That may convince more people to
get involved. MA
Andy Panoncillo
[email protected]
Edition: Model Aviation - 2009/06
Page Numbers: 49,50,51,52,54,56
Edition: Model Aviation - 2009/06
Page Numbers: 49,50,51,52,54,56
June 2009 49
THE HELICOPTER HAS
become one of the most
popular RC interests on the
market because of the
emergence of numerous
affordable and easy-to-build
kits. Many kits are designed
to be set up in a way that
allows beginners to learn and
progress with them as
advanced flying skills are
acquired.
These pilots can fly the
same helicopter from training
gear to 3-D, if they choose,
by making minor mechanical
adjustments or installing a
few upgrades. All the while,
they can fly a machine that is
safe and reliable—as long as
they follow the assembly and
maintenance tips I’m going to
cover.
Regardless of whether it is
a helicopter, airplane, glider, etc., aircraft
need attention before you take them out to
the field—especially if you’re going to a
fun-fly, where many people are either going
to be watching you or flying beside you.
Good maintenance also protects the
investment; some machines out there cost
their owners fairly good amounts of cash.
The modern RC helicopter is much
easier to build, set up, and maintain than
older versions. This is because they have
fewer parts, they self-align during
assembly, and they have factory-balanced
components, which makes the spinning
parts operate more smoothly, causing less
overall stress on the airframe.
by
Andy
Panoncillo
No matter how
complex the
machine, good
maintenance
practices can
ensure the
success of any
project.
06sig2.QXD 4/22/09 10:50 AM Page 49
50 MODEL AVIATION
Ball-link pliers, wire cutters, needle-nose pliers, and c-clip pliers
are just a few essentials of helicopter maintenance.
Some wrenches have special functions other than the obvious. The
Align types have a cavity that can store bolts, nuts, or spare tips.
Above: A simple caliper can make your build or maintenance
easy and accurate. A digital caliper is extremely handy, for
those who don’t mind the extra cost.
Right: Regularly inspect main and tail blades. Insects can load up
quickly on their LEs. Look carefully for nicks and cracks.
Keep the model organized by assigning fueltank
lines specific colors. Zip ties and doublestick
foam tape bind loose items so they don’t
come to harm.
Socket wrenches come in all shapes; these
are good for 30-size and larger helicopters.
Metric sizes from 4mm to 14mm are typically
useful.
Engine service requires a crankshaft
lock or piston lock (foreground).
Correctly tightening the fan/clutch
assembly would be impossible
without one.
Photos by the author
Keeping a good-running starter and battery
prevents hassles at the field when you’re
ready to fly your aircraft. A 4S Li-Poly battery
is used here.
06sig2.QXD 4/22/09 10:51 AM Page 50
June 2009 51
The fact that a helicopter has many moving parts dictates a
degree of fanaticism regarding equipment installation. Neatness
counts and can prevent heartache later.
Whether electric- or glow-powered, a secure canopy will help
streamline the machine and keep equipment as clean as possible.
Left: At midstick on the
transmitter, the swashplate
and lever should be level.
The servo arms should be
set up for equal throw on
each side of the midstick
point.
Right: Some pilots no longer
use a pitch gauge, and it works
for them. I recommend one to
monitor the amount of pitch,
to assure that the mechanics
are within limits.
Above: Keep an eye on the bottom for
excessive wear on struts and skids.
Silicone-rubber bumpers are available to
protect landing gear.
Right: This model’s wiring is mostly
hidden on the inside of the frame. Nice!
Electrics rarely get dirty, but they should
be inspected as frequently as enginepowered
aircraft.
06sig2.QXD 4/22/09 10:18 AM Page 51
Even smaller 400-class machines need regular maintenance. Tug on the ball
links now and then to check for security.
52 MODEL AVIATION
While a helicopter is transported, bouncing can wear on its
mechanics unless a simple blade holder is used.
Whether the helicopter tail control is driven by a belt or torque
tube, make sure that the bearings are properly lubricated and
cleaned to prevent any chance of binding.
A good fuel filter ensures that clean fuel will
get to the engine, prolonging its life and
ensuring that optimal power can be
achieved.
The requirement for special tools to
maintain an RC helicopter is behind us,
but we still need some essential devices to
keep our machines operating well. You
can find these tools in the average flight
box.
Head Assembly: This is where most of
the work happens in terms of setup and
maintenance. That is especially true now
that many head-design assemblies include
programmable linkage features that allow
the sensitivity to be customized to suit a
specific taste or flying style.
A gadget that I fully recommend is a
swashplate leveling tool. Using it the right
way eliminates most problems with a
helicopter’s trimming in terms of control
interaction. Not only will this instrument
indicate a neutral state, but it will also
clearly show when the servos are causing
unwanted input that can often occur in
CCPM (Cyclic/Collective Pitch Mixing)
mechanics.
For instance, if right cyclic also inputs
aft cyclic, this requires the pilot to input
forward control when only roll input is
enacted with movement of the transmitter
gimbal. It’s like flying a model that is
constantly out of trim.
You can purchase a swashplate leveling
tool from a Web site or hobby shop that
06sig2.QXD 4/22/09 10:18 AM Page 52
handles RC helicopters. This device can
be used for the majority of helicopter sizes,
from 30 to 90. If you have a 450-size
model, you’ll need the smallest swashplate
leveler.
Use the leveling tool to identify
interactions on the bench. Adjustments
can be made mechanically or with a
program mix in the radio. Most
interactions can be detected while testing
the collective pitch control; watch the
bubbles as the swashplate moves up and
down.
Off-center indications will identify
early what servo or linkage needs
tweaking. It’s well worth the effort,
because your machine will fly practically
perfect on its first hop.
Ball Links: These are the primary
connection between all of the model’s
mechanics. They should fit securely but
move freely.
A tight link offers security, but its
binding can prevent mechanics from
recentering or operating at their full
potential. A machine with tight links will
eventually break in, but it might be extra
work for the pilot to operate until then.
A ball-link sizing tool will condition
any linkages that are too tight on their ball
ends. Use this instrument sparingly; an
oversized linkage won’t stay attached and
will be less precise and more dangerous to
operate.
Links are inexpensive, so buy a pack and
have it handy for replacement in case a
preflight reveals a faulty area.
Pitch Gauge: With enough experience,
some pilots avoid using a pitch gauge.
They’re either not picky or figure that
flight-testing will reveal any issues and
correct them later.
That’s not the method for me.
Regardless of skill level, the pitch gauge
can offer great information that will help
monitor the amount of pitch in the blades.
This way, I know if the design limits are
exceeded and whether or not the amount of
pitch a specific engine can handle is
delivered.
If your helicopter’s head mechanics are
adjustable (programmable), changes to the
linkage geometry can be gauged with a
measuring tool such as a pitch gauge. Keep
a log of the readings; in the event of a
mishap, the helicopter can be returned to
those settings after the rebuild.
Caliper: A mechanical or digital caliper is
an invaluable tool for building, maintenance,
and/or repair. This device can be used to
ensure equal measurements on multiple
links and identify other points on the
helicopter that need to be equal on each
side.
Calipers are also ideal for identifying
measurements called out in the instruction
manual and for verifying correctness or
deviation of the actual assembly. It takes
out the guesswork.
With the flybar, the rod needs to be
centered within the assembly. A caliper
makes it easy to compare both sides without
having to squint to look at the fine lines of a
precision metric ruler.
Frame: When it comes to frame assembly,
the majority, if not all, of the kits self-align
during assembly. That is extraordinarily
helpful for the experienced pilot who is
working quickly to get a machine back in
the air, and it is especially helpful to the
new pilot who is starting out in this hobby.
Assemble the frame with the main shaft
temporarily installed inside the main
bearings. While tightening the bearingblock
screws, check periodically to make
sure that the shaft freely slips up and down.
A tight fit indicates misalignment or merely
a set of mounting screws that are tightened
more or less than the others; either is easy to
fix.
The essential thing is the servo locations
and proper servo-horn alignment. Assign
and locate servo arms once they have been
neutralized with both transmitter sticks in
the center (throttle at the halfway point).
Follow the instructions and set the servo
arms so that they align with the frame/case
as directed. Servo-arm length is critical as
well, so be diligent. Variations will cause
unwanted control input mixing.
Most servo arms are located with the
arm 90° of the servo case. This directive in
a setup system is commonly referred to as
“The Rule of 90.”
A servo arm and linkage system that is
90° relative to a specific pivot point will
deliver equal throw on either side. All
helicopters demand that equal throw at
least be available for the system’s
mechanics to operate correctly.
Engines: Engine technology has improved
tremendously, and that includes advances
in power, smoother throttle response, and,
thanks to new carburetor designs, more
reliability and stronger fuel-delivery
capabilities. In addition, the power plants
cool better overall, promoting longer life.
However, despite all of this, care is
necessary to keep engines running well. I
recommend a random check on the
mounting bolts or screws, since these
points are subjected to stress and vibration
every time the helicopter is flown.
Another area of the engine you should
inspect is the glow plug. Many of us don’t
change one of these until we learn that it is
no longer working—either during start-up
or, worse, during flight. The latter can be
costly if your machine is in a position
from which it won’t recover gracefully.
Check the glow plug on a regular basis,
and replace it if at all suspect of fault. The
average cost for a good plug is $5. That’s
certainly better than paying for costly
replacement parts.
Helicopter fuel is known to have more
oil and nitromethane content, to promote
better performance and cooling. Our
engines will run on airplane fuel, but they
may not last as long or be as reliable. Why
chance it?
Spending a few extra bucks on the right
fuel will pay you back later. You won’t be
sorry; use “helicopter”-specified fuel.
Tail and Tailboom: Model helicopters
have either a carbon fiber or aluminum
tailboom. Good tailboom supports offer
stability and prevent distortion.
Make sure that your machine’s
tailboom supports are fastened well.
Assemble them with an epoxy such as J.B.
Weld, to prevent the mounting lugs from
separating from the support material.
Include these mounting points during a
routine preflight check or a once-over
after a hard landing. Look for any
fractures or cracks, and make sure that the
tailboom clamps are tightened properly;
don’t overtorque the mounting bolts.
You should also thoroughly inspect the
tail section, since the high speeds at which
the parts operate can create sudden
irregularities when fault occurs. Any
suspect vibration that you see or hear can
quickly cause such problems as drifting
or, worse, total failure and a crash.
The introduction of the open tail
gearbox design greatly helped RC
helicopter pilots with maintenance. It
made points such as the gear mesh much
easier to inspect and adjust if needed.
Open gearboxes don’t require
lubrication, but keep them as clean as
possible to prevent excessive wear. We
need to lubricate areas that have slide
bearings, such as the tail-rotor pitchcontrol
slider.
Regularly inspect any screws and
bolts—particularly setscrews. Where
metal-to-metal contact is made, treat the
machine threads with a thread-locking
compound. Refresh the compound
whenever a screw is retightened or
replaced. It works best on threads that are
free from lubricant.
Keep your helicopter manual handy at all
times. Even when disassembly is done
with the utmost care, reassembly can be
confusing. Having at least a part
explosion illustration is a comfort.
Incorrectly reassembling an assembly can
have disastrous consequences.
Thanks to improvements in materials
and helicopter design, we enjoy flying
more and worrying about our machines
less. They can take more flight
punishment and therefore hold up better in
a mishap.
If we do our part in inspecting and
maintaining our models, fellow RCers—
and especially the public audience—will
appreciate how we respect our hobby/
sport. That may convince more people to
get involved. MA
Andy Panoncillo
[email protected]
Edition: Model Aviation - 2009/06
Page Numbers: 49,50,51,52,54,56
June 2009 49
THE HELICOPTER HAS
become one of the most
popular RC interests on the
market because of the
emergence of numerous
affordable and easy-to-build
kits. Many kits are designed
to be set up in a way that
allows beginners to learn and
progress with them as
advanced flying skills are
acquired.
These pilots can fly the
same helicopter from training
gear to 3-D, if they choose,
by making minor mechanical
adjustments or installing a
few upgrades. All the while,
they can fly a machine that is
safe and reliable—as long as
they follow the assembly and
maintenance tips I’m going to
cover.
Regardless of whether it is
a helicopter, airplane, glider, etc., aircraft
need attention before you take them out to
the field—especially if you’re going to a
fun-fly, where many people are either going
to be watching you or flying beside you.
Good maintenance also protects the
investment; some machines out there cost
their owners fairly good amounts of cash.
The modern RC helicopter is much
easier to build, set up, and maintain than
older versions. This is because they have
fewer parts, they self-align during
assembly, and they have factory-balanced
components, which makes the spinning
parts operate more smoothly, causing less
overall stress on the airframe.
by
Andy
Panoncillo
No matter how
complex the
machine, good
maintenance
practices can
ensure the
success of any
project.
06sig2.QXD 4/22/09 10:50 AM Page 49
50 MODEL AVIATION
Ball-link pliers, wire cutters, needle-nose pliers, and c-clip pliers
are just a few essentials of helicopter maintenance.
Some wrenches have special functions other than the obvious. The
Align types have a cavity that can store bolts, nuts, or spare tips.
Above: A simple caliper can make your build or maintenance
easy and accurate. A digital caliper is extremely handy, for
those who don’t mind the extra cost.
Right: Regularly inspect main and tail blades. Insects can load up
quickly on their LEs. Look carefully for nicks and cracks.
Keep the model organized by assigning fueltank
lines specific colors. Zip ties and doublestick
foam tape bind loose items so they don’t
come to harm.
Socket wrenches come in all shapes; these
are good for 30-size and larger helicopters.
Metric sizes from 4mm to 14mm are typically
useful.
Engine service requires a crankshaft
lock or piston lock (foreground).
Correctly tightening the fan/clutch
assembly would be impossible
without one.
Photos by the author
Keeping a good-running starter and battery
prevents hassles at the field when you’re
ready to fly your aircraft. A 4S Li-Poly battery
is used here.
06sig2.QXD 4/22/09 10:51 AM Page 50
June 2009 51
The fact that a helicopter has many moving parts dictates a
degree of fanaticism regarding equipment installation. Neatness
counts and can prevent heartache later.
Whether electric- or glow-powered, a secure canopy will help
streamline the machine and keep equipment as clean as possible.
Left: At midstick on the
transmitter, the swashplate
and lever should be level.
The servo arms should be
set up for equal throw on
each side of the midstick
point.
Right: Some pilots no longer
use a pitch gauge, and it works
for them. I recommend one to
monitor the amount of pitch,
to assure that the mechanics
are within limits.
Above: Keep an eye on the bottom for
excessive wear on struts and skids.
Silicone-rubber bumpers are available to
protect landing gear.
Right: This model’s wiring is mostly
hidden on the inside of the frame. Nice!
Electrics rarely get dirty, but they should
be inspected as frequently as enginepowered
aircraft.
06sig2.QXD 4/22/09 10:18 AM Page 51
Even smaller 400-class machines need regular maintenance. Tug on the ball
links now and then to check for security.
52 MODEL AVIATION
While a helicopter is transported, bouncing can wear on its
mechanics unless a simple blade holder is used.
Whether the helicopter tail control is driven by a belt or torque
tube, make sure that the bearings are properly lubricated and
cleaned to prevent any chance of binding.
A good fuel filter ensures that clean fuel will
get to the engine, prolonging its life and
ensuring that optimal power can be
achieved.
The requirement for special tools to
maintain an RC helicopter is behind us,
but we still need some essential devices to
keep our machines operating well. You
can find these tools in the average flight
box.
Head Assembly: This is where most of
the work happens in terms of setup and
maintenance. That is especially true now
that many head-design assemblies include
programmable linkage features that allow
the sensitivity to be customized to suit a
specific taste or flying style.
A gadget that I fully recommend is a
swashplate leveling tool. Using it the right
way eliminates most problems with a
helicopter’s trimming in terms of control
interaction. Not only will this instrument
indicate a neutral state, but it will also
clearly show when the servos are causing
unwanted input that can often occur in
CCPM (Cyclic/Collective Pitch Mixing)
mechanics.
For instance, if right cyclic also inputs
aft cyclic, this requires the pilot to input
forward control when only roll input is
enacted with movement of the transmitter
gimbal. It’s like flying a model that is
constantly out of trim.
You can purchase a swashplate leveling
tool from a Web site or hobby shop that
06sig2.QXD 4/22/09 10:18 AM Page 52
handles RC helicopters. This device can
be used for the majority of helicopter sizes,
from 30 to 90. If you have a 450-size
model, you’ll need the smallest swashplate
leveler.
Use the leveling tool to identify
interactions on the bench. Adjustments
can be made mechanically or with a
program mix in the radio. Most
interactions can be detected while testing
the collective pitch control; watch the
bubbles as the swashplate moves up and
down.
Off-center indications will identify
early what servo or linkage needs
tweaking. It’s well worth the effort,
because your machine will fly practically
perfect on its first hop.
Ball Links: These are the primary
connection between all of the model’s
mechanics. They should fit securely but
move freely.
A tight link offers security, but its
binding can prevent mechanics from
recentering or operating at their full
potential. A machine with tight links will
eventually break in, but it might be extra
work for the pilot to operate until then.
A ball-link sizing tool will condition
any linkages that are too tight on their ball
ends. Use this instrument sparingly; an
oversized linkage won’t stay attached and
will be less precise and more dangerous to
operate.
Links are inexpensive, so buy a pack and
have it handy for replacement in case a
preflight reveals a faulty area.
Pitch Gauge: With enough experience,
some pilots avoid using a pitch gauge.
They’re either not picky or figure that
flight-testing will reveal any issues and
correct them later.
That’s not the method for me.
Regardless of skill level, the pitch gauge
can offer great information that will help
monitor the amount of pitch in the blades.
This way, I know if the design limits are
exceeded and whether or not the amount of
pitch a specific engine can handle is
delivered.
If your helicopter’s head mechanics are
adjustable (programmable), changes to the
linkage geometry can be gauged with a
measuring tool such as a pitch gauge. Keep
a log of the readings; in the event of a
mishap, the helicopter can be returned to
those settings after the rebuild.
Caliper: A mechanical or digital caliper is
an invaluable tool for building, maintenance,
and/or repair. This device can be used to
ensure equal measurements on multiple
links and identify other points on the
helicopter that need to be equal on each
side.
Calipers are also ideal for identifying
measurements called out in the instruction
manual and for verifying correctness or
deviation of the actual assembly. It takes
out the guesswork.
With the flybar, the rod needs to be
centered within the assembly. A caliper
makes it easy to compare both sides without
having to squint to look at the fine lines of a
precision metric ruler.
Frame: When it comes to frame assembly,
the majority, if not all, of the kits self-align
during assembly. That is extraordinarily
helpful for the experienced pilot who is
working quickly to get a machine back in
the air, and it is especially helpful to the
new pilot who is starting out in this hobby.
Assemble the frame with the main shaft
temporarily installed inside the main
bearings. While tightening the bearingblock
screws, check periodically to make
sure that the shaft freely slips up and down.
A tight fit indicates misalignment or merely
a set of mounting screws that are tightened
more or less than the others; either is easy to
fix.
The essential thing is the servo locations
and proper servo-horn alignment. Assign
and locate servo arms once they have been
neutralized with both transmitter sticks in
the center (throttle at the halfway point).
Follow the instructions and set the servo
arms so that they align with the frame/case
as directed. Servo-arm length is critical as
well, so be diligent. Variations will cause
unwanted control input mixing.
Most servo arms are located with the
arm 90° of the servo case. This directive in
a setup system is commonly referred to as
“The Rule of 90.”
A servo arm and linkage system that is
90° relative to a specific pivot point will
deliver equal throw on either side. All
helicopters demand that equal throw at
least be available for the system’s
mechanics to operate correctly.
Engines: Engine technology has improved
tremendously, and that includes advances
in power, smoother throttle response, and,
thanks to new carburetor designs, more
reliability and stronger fuel-delivery
capabilities. In addition, the power plants
cool better overall, promoting longer life.
However, despite all of this, care is
necessary to keep engines running well. I
recommend a random check on the
mounting bolts or screws, since these
points are subjected to stress and vibration
every time the helicopter is flown.
Another area of the engine you should
inspect is the glow plug. Many of us don’t
change one of these until we learn that it is
no longer working—either during start-up
or, worse, during flight. The latter can be
costly if your machine is in a position
from which it won’t recover gracefully.
Check the glow plug on a regular basis,
and replace it if at all suspect of fault. The
average cost for a good plug is $5. That’s
certainly better than paying for costly
replacement parts.
Helicopter fuel is known to have more
oil and nitromethane content, to promote
better performance and cooling. Our
engines will run on airplane fuel, but they
may not last as long or be as reliable. Why
chance it?
Spending a few extra bucks on the right
fuel will pay you back later. You won’t be
sorry; use “helicopter”-specified fuel.
Tail and Tailboom: Model helicopters
have either a carbon fiber or aluminum
tailboom. Good tailboom supports offer
stability and prevent distortion.
Make sure that your machine’s
tailboom supports are fastened well.
Assemble them with an epoxy such as J.B.
Weld, to prevent the mounting lugs from
separating from the support material.
Include these mounting points during a
routine preflight check or a once-over
after a hard landing. Look for any
fractures or cracks, and make sure that the
tailboom clamps are tightened properly;
don’t overtorque the mounting bolts.
You should also thoroughly inspect the
tail section, since the high speeds at which
the parts operate can create sudden
irregularities when fault occurs. Any
suspect vibration that you see or hear can
quickly cause such problems as drifting
or, worse, total failure and a crash.
The introduction of the open tail
gearbox design greatly helped RC
helicopter pilots with maintenance. It
made points such as the gear mesh much
easier to inspect and adjust if needed.
Open gearboxes don’t require
lubrication, but keep them as clean as
possible to prevent excessive wear. We
need to lubricate areas that have slide
bearings, such as the tail-rotor pitchcontrol
slider.
Regularly inspect any screws and
bolts—particularly setscrews. Where
metal-to-metal contact is made, treat the
machine threads with a thread-locking
compound. Refresh the compound
whenever a screw is retightened or
replaced. It works best on threads that are
free from lubricant.
Keep your helicopter manual handy at all
times. Even when disassembly is done
with the utmost care, reassembly can be
confusing. Having at least a part
explosion illustration is a comfort.
Incorrectly reassembling an assembly can
have disastrous consequences.
Thanks to improvements in materials
and helicopter design, we enjoy flying
more and worrying about our machines
less. They can take more flight
punishment and therefore hold up better in
a mishap.
If we do our part in inspecting and
maintaining our models, fellow RCers—
and especially the public audience—will
appreciate how we respect our hobby/
sport. That may convince more people to
get involved. MA
Andy Panoncillo
[email protected]
Edition: Model Aviation - 2009/06
Page Numbers: 49,50,51,52,54,56
June 2009 49
THE HELICOPTER HAS
become one of the most
popular RC interests on the
market because of the
emergence of numerous
affordable and easy-to-build
kits. Many kits are designed
to be set up in a way that
allows beginners to learn and
progress with them as
advanced flying skills are
acquired.
These pilots can fly the
same helicopter from training
gear to 3-D, if they choose,
by making minor mechanical
adjustments or installing a
few upgrades. All the while,
they can fly a machine that is
safe and reliable—as long as
they follow the assembly and
maintenance tips I’m going to
cover.
Regardless of whether it is
a helicopter, airplane, glider, etc., aircraft
need attention before you take them out to
the field—especially if you’re going to a
fun-fly, where many people are either going
to be watching you or flying beside you.
Good maintenance also protects the
investment; some machines out there cost
their owners fairly good amounts of cash.
The modern RC helicopter is much
easier to build, set up, and maintain than
older versions. This is because they have
fewer parts, they self-align during
assembly, and they have factory-balanced
components, which makes the spinning
parts operate more smoothly, causing less
overall stress on the airframe.
by
Andy
Panoncillo
No matter how
complex the
machine, good
maintenance
practices can
ensure the
success of any
project.
06sig2.QXD 4/22/09 10:50 AM Page 49
50 MODEL AVIATION
Ball-link pliers, wire cutters, needle-nose pliers, and c-clip pliers
are just a few essentials of helicopter maintenance.
Some wrenches have special functions other than the obvious. The
Align types have a cavity that can store bolts, nuts, or spare tips.
Above: A simple caliper can make your build or maintenance
easy and accurate. A digital caliper is extremely handy, for
those who don’t mind the extra cost.
Right: Regularly inspect main and tail blades. Insects can load up
quickly on their LEs. Look carefully for nicks and cracks.
Keep the model organized by assigning fueltank
lines specific colors. Zip ties and doublestick
foam tape bind loose items so they don’t
come to harm.
Socket wrenches come in all shapes; these
are good for 30-size and larger helicopters.
Metric sizes from 4mm to 14mm are typically
useful.
Engine service requires a crankshaft
lock or piston lock (foreground).
Correctly tightening the fan/clutch
assembly would be impossible
without one.
Photos by the author
Keeping a good-running starter and battery
prevents hassles at the field when you’re
ready to fly your aircraft. A 4S Li-Poly battery
is used here.
06sig2.QXD 4/22/09 10:51 AM Page 50
June 2009 51
The fact that a helicopter has many moving parts dictates a
degree of fanaticism regarding equipment installation. Neatness
counts and can prevent heartache later.
Whether electric- or glow-powered, a secure canopy will help
streamline the machine and keep equipment as clean as possible.
Left: At midstick on the
transmitter, the swashplate
and lever should be level.
The servo arms should be
set up for equal throw on
each side of the midstick
point.
Right: Some pilots no longer
use a pitch gauge, and it works
for them. I recommend one to
monitor the amount of pitch,
to assure that the mechanics
are within limits.
Above: Keep an eye on the bottom for
excessive wear on struts and skids.
Silicone-rubber bumpers are available to
protect landing gear.
Right: This model’s wiring is mostly
hidden on the inside of the frame. Nice!
Electrics rarely get dirty, but they should
be inspected as frequently as enginepowered
aircraft.
06sig2.QXD 4/22/09 10:18 AM Page 51
Even smaller 400-class machines need regular maintenance. Tug on the ball
links now and then to check for security.
52 MODEL AVIATION
While a helicopter is transported, bouncing can wear on its
mechanics unless a simple blade holder is used.
Whether the helicopter tail control is driven by a belt or torque
tube, make sure that the bearings are properly lubricated and
cleaned to prevent any chance of binding.
A good fuel filter ensures that clean fuel will
get to the engine, prolonging its life and
ensuring that optimal power can be
achieved.
The requirement for special tools to
maintain an RC helicopter is behind us,
but we still need some essential devices to
keep our machines operating well. You
can find these tools in the average flight
box.
Head Assembly: This is where most of
the work happens in terms of setup and
maintenance. That is especially true now
that many head-design assemblies include
programmable linkage features that allow
the sensitivity to be customized to suit a
specific taste or flying style.
A gadget that I fully recommend is a
swashplate leveling tool. Using it the right
way eliminates most problems with a
helicopter’s trimming in terms of control
interaction. Not only will this instrument
indicate a neutral state, but it will also
clearly show when the servos are causing
unwanted input that can often occur in
CCPM (Cyclic/Collective Pitch Mixing)
mechanics.
For instance, if right cyclic also inputs
aft cyclic, this requires the pilot to input
forward control when only roll input is
enacted with movement of the transmitter
gimbal. It’s like flying a model that is
constantly out of trim.
You can purchase a swashplate leveling
tool from a Web site or hobby shop that
06sig2.QXD 4/22/09 10:18 AM Page 52
handles RC helicopters. This device can
be used for the majority of helicopter sizes,
from 30 to 90. If you have a 450-size
model, you’ll need the smallest swashplate
leveler.
Use the leveling tool to identify
interactions on the bench. Adjustments
can be made mechanically or with a
program mix in the radio. Most
interactions can be detected while testing
the collective pitch control; watch the
bubbles as the swashplate moves up and
down.
Off-center indications will identify
early what servo or linkage needs
tweaking. It’s well worth the effort,
because your machine will fly practically
perfect on its first hop.
Ball Links: These are the primary
connection between all of the model’s
mechanics. They should fit securely but
move freely.
A tight link offers security, but its
binding can prevent mechanics from
recentering or operating at their full
potential. A machine with tight links will
eventually break in, but it might be extra
work for the pilot to operate until then.
A ball-link sizing tool will condition
any linkages that are too tight on their ball
ends. Use this instrument sparingly; an
oversized linkage won’t stay attached and
will be less precise and more dangerous to
operate.
Links are inexpensive, so buy a pack and
have it handy for replacement in case a
preflight reveals a faulty area.
Pitch Gauge: With enough experience,
some pilots avoid using a pitch gauge.
They’re either not picky or figure that
flight-testing will reveal any issues and
correct them later.
That’s not the method for me.
Regardless of skill level, the pitch gauge
can offer great information that will help
monitor the amount of pitch in the blades.
This way, I know if the design limits are
exceeded and whether or not the amount of
pitch a specific engine can handle is
delivered.
If your helicopter’s head mechanics are
adjustable (programmable), changes to the
linkage geometry can be gauged with a
measuring tool such as a pitch gauge. Keep
a log of the readings; in the event of a
mishap, the helicopter can be returned to
those settings after the rebuild.
Caliper: A mechanical or digital caliper is
an invaluable tool for building, maintenance,
and/or repair. This device can be used to
ensure equal measurements on multiple
links and identify other points on the
helicopter that need to be equal on each
side.
Calipers are also ideal for identifying
measurements called out in the instruction
manual and for verifying correctness or
deviation of the actual assembly. It takes
out the guesswork.
With the flybar, the rod needs to be
centered within the assembly. A caliper
makes it easy to compare both sides without
having to squint to look at the fine lines of a
precision metric ruler.
Frame: When it comes to frame assembly,
the majority, if not all, of the kits self-align
during assembly. That is extraordinarily
helpful for the experienced pilot who is
working quickly to get a machine back in
the air, and it is especially helpful to the
new pilot who is starting out in this hobby.
Assemble the frame with the main shaft
temporarily installed inside the main
bearings. While tightening the bearingblock
screws, check periodically to make
sure that the shaft freely slips up and down.
A tight fit indicates misalignment or merely
a set of mounting screws that are tightened
more or less than the others; either is easy to
fix.
The essential thing is the servo locations
and proper servo-horn alignment. Assign
and locate servo arms once they have been
neutralized with both transmitter sticks in
the center (throttle at the halfway point).
Follow the instructions and set the servo
arms so that they align with the frame/case
as directed. Servo-arm length is critical as
well, so be diligent. Variations will cause
unwanted control input mixing.
Most servo arms are located with the
arm 90° of the servo case. This directive in
a setup system is commonly referred to as
“The Rule of 90.”
A servo arm and linkage system that is
90° relative to a specific pivot point will
deliver equal throw on either side. All
helicopters demand that equal throw at
least be available for the system’s
mechanics to operate correctly.
Engines: Engine technology has improved
tremendously, and that includes advances
in power, smoother throttle response, and,
thanks to new carburetor designs, more
reliability and stronger fuel-delivery
capabilities. In addition, the power plants
cool better overall, promoting longer life.
However, despite all of this, care is
necessary to keep engines running well. I
recommend a random check on the
mounting bolts or screws, since these
points are subjected to stress and vibration
every time the helicopter is flown.
Another area of the engine you should
inspect is the glow plug. Many of us don’t
change one of these until we learn that it is
no longer working—either during start-up
or, worse, during flight. The latter can be
costly if your machine is in a position
from which it won’t recover gracefully.
Check the glow plug on a regular basis,
and replace it if at all suspect of fault. The
average cost for a good plug is $5. That’s
certainly better than paying for costly
replacement parts.
Helicopter fuel is known to have more
oil and nitromethane content, to promote
better performance and cooling. Our
engines will run on airplane fuel, but they
may not last as long or be as reliable. Why
chance it?
Spending a few extra bucks on the right
fuel will pay you back later. You won’t be
sorry; use “helicopter”-specified fuel.
Tail and Tailboom: Model helicopters
have either a carbon fiber or aluminum
tailboom. Good tailboom supports offer
stability and prevent distortion.
Make sure that your machine’s
tailboom supports are fastened well.
Assemble them with an epoxy such as J.B.
Weld, to prevent the mounting lugs from
separating from the support material.
Include these mounting points during a
routine preflight check or a once-over
after a hard landing. Look for any
fractures or cracks, and make sure that the
tailboom clamps are tightened properly;
don’t overtorque the mounting bolts.
You should also thoroughly inspect the
tail section, since the high speeds at which
the parts operate can create sudden
irregularities when fault occurs. Any
suspect vibration that you see or hear can
quickly cause such problems as drifting
or, worse, total failure and a crash.
The introduction of the open tail
gearbox design greatly helped RC
helicopter pilots with maintenance. It
made points such as the gear mesh much
easier to inspect and adjust if needed.
Open gearboxes don’t require
lubrication, but keep them as clean as
possible to prevent excessive wear. We
need to lubricate areas that have slide
bearings, such as the tail-rotor pitchcontrol
slider.
Regularly inspect any screws and
bolts—particularly setscrews. Where
metal-to-metal contact is made, treat the
machine threads with a thread-locking
compound. Refresh the compound
whenever a screw is retightened or
replaced. It works best on threads that are
free from lubricant.
Keep your helicopter manual handy at all
times. Even when disassembly is done
with the utmost care, reassembly can be
confusing. Having at least a part
explosion illustration is a comfort.
Incorrectly reassembling an assembly can
have disastrous consequences.
Thanks to improvements in materials
and helicopter design, we enjoy flying
more and worrying about our machines
less. They can take more flight
punishment and therefore hold up better in
a mishap.
If we do our part in inspecting and
maintaining our models, fellow RCers—
and especially the public audience—will
appreciate how we respect our hobby/
sport. That may convince more people to
get involved. MA
Andy Panoncillo
[email protected]
Edition: Model Aviation - 2009/06
Page Numbers: 49,50,51,52,54,56
June 2009 49
THE HELICOPTER HAS
become one of the most
popular RC interests on the
market because of the
emergence of numerous
affordable and easy-to-build
kits. Many kits are designed
to be set up in a way that
allows beginners to learn and
progress with them as
advanced flying skills are
acquired.
These pilots can fly the
same helicopter from training
gear to 3-D, if they choose,
by making minor mechanical
adjustments or installing a
few upgrades. All the while,
they can fly a machine that is
safe and reliable—as long as
they follow the assembly and
maintenance tips I’m going to
cover.
Regardless of whether it is
a helicopter, airplane, glider, etc., aircraft
need attention before you take them out to
the field—especially if you’re going to a
fun-fly, where many people are either going
to be watching you or flying beside you.
Good maintenance also protects the
investment; some machines out there cost
their owners fairly good amounts of cash.
The modern RC helicopter is much
easier to build, set up, and maintain than
older versions. This is because they have
fewer parts, they self-align during
assembly, and they have factory-balanced
components, which makes the spinning
parts operate more smoothly, causing less
overall stress on the airframe.
by
Andy
Panoncillo
No matter how
complex the
machine, good
maintenance
practices can
ensure the
success of any
project.
06sig2.QXD 4/22/09 10:50 AM Page 49
50 MODEL AVIATION
Ball-link pliers, wire cutters, needle-nose pliers, and c-clip pliers
are just a few essentials of helicopter maintenance.
Some wrenches have special functions other than the obvious. The
Align types have a cavity that can store bolts, nuts, or spare tips.
Above: A simple caliper can make your build or maintenance
easy and accurate. A digital caliper is extremely handy, for
those who don’t mind the extra cost.
Right: Regularly inspect main and tail blades. Insects can load up
quickly on their LEs. Look carefully for nicks and cracks.
Keep the model organized by assigning fueltank
lines specific colors. Zip ties and doublestick
foam tape bind loose items so they don’t
come to harm.
Socket wrenches come in all shapes; these
are good for 30-size and larger helicopters.
Metric sizes from 4mm to 14mm are typically
useful.
Engine service requires a crankshaft
lock or piston lock (foreground).
Correctly tightening the fan/clutch
assembly would be impossible
without one.
Photos by the author
Keeping a good-running starter and battery
prevents hassles at the field when you’re
ready to fly your aircraft. A 4S Li-Poly battery
is used here.
06sig2.QXD 4/22/09 10:51 AM Page 50
June 2009 51
The fact that a helicopter has many moving parts dictates a
degree of fanaticism regarding equipment installation. Neatness
counts and can prevent heartache later.
Whether electric- or glow-powered, a secure canopy will help
streamline the machine and keep equipment as clean as possible.
Left: At midstick on the
transmitter, the swashplate
and lever should be level.
The servo arms should be
set up for equal throw on
each side of the midstick
point.
Right: Some pilots no longer
use a pitch gauge, and it works
for them. I recommend one to
monitor the amount of pitch,
to assure that the mechanics
are within limits.
Above: Keep an eye on the bottom for
excessive wear on struts and skids.
Silicone-rubber bumpers are available to
protect landing gear.
Right: This model’s wiring is mostly
hidden on the inside of the frame. Nice!
Electrics rarely get dirty, but they should
be inspected as frequently as enginepowered
aircraft.
06sig2.QXD 4/22/09 10:18 AM Page 51
Even smaller 400-class machines need regular maintenance. Tug on the ball
links now and then to check for security.
52 MODEL AVIATION
While a helicopter is transported, bouncing can wear on its
mechanics unless a simple blade holder is used.
Whether the helicopter tail control is driven by a belt or torque
tube, make sure that the bearings are properly lubricated and
cleaned to prevent any chance of binding.
A good fuel filter ensures that clean fuel will
get to the engine, prolonging its life and
ensuring that optimal power can be
achieved.
The requirement for special tools to
maintain an RC helicopter is behind us,
but we still need some essential devices to
keep our machines operating well. You
can find these tools in the average flight
box.
Head Assembly: This is where most of
the work happens in terms of setup and
maintenance. That is especially true now
that many head-design assemblies include
programmable linkage features that allow
the sensitivity to be customized to suit a
specific taste or flying style.
A gadget that I fully recommend is a
swashplate leveling tool. Using it the right
way eliminates most problems with a
helicopter’s trimming in terms of control
interaction. Not only will this instrument
indicate a neutral state, but it will also
clearly show when the servos are causing
unwanted input that can often occur in
CCPM (Cyclic/Collective Pitch Mixing)
mechanics.
For instance, if right cyclic also inputs
aft cyclic, this requires the pilot to input
forward control when only roll input is
enacted with movement of the transmitter
gimbal. It’s like flying a model that is
constantly out of trim.
You can purchase a swashplate leveling
tool from a Web site or hobby shop that
06sig2.QXD 4/22/09 10:18 AM Page 52
handles RC helicopters. This device can
be used for the majority of helicopter sizes,
from 30 to 90. If you have a 450-size
model, you’ll need the smallest swashplate
leveler.
Use the leveling tool to identify
interactions on the bench. Adjustments
can be made mechanically or with a
program mix in the radio. Most
interactions can be detected while testing
the collective pitch control; watch the
bubbles as the swashplate moves up and
down.
Off-center indications will identify
early what servo or linkage needs
tweaking. It’s well worth the effort,
because your machine will fly practically
perfect on its first hop.
Ball Links: These are the primary
connection between all of the model’s
mechanics. They should fit securely but
move freely.
A tight link offers security, but its
binding can prevent mechanics from
recentering or operating at their full
potential. A machine with tight links will
eventually break in, but it might be extra
work for the pilot to operate until then.
A ball-link sizing tool will condition
any linkages that are too tight on their ball
ends. Use this instrument sparingly; an
oversized linkage won’t stay attached and
will be less precise and more dangerous to
operate.
Links are inexpensive, so buy a pack and
have it handy for replacement in case a
preflight reveals a faulty area.
Pitch Gauge: With enough experience,
some pilots avoid using a pitch gauge.
They’re either not picky or figure that
flight-testing will reveal any issues and
correct them later.
That’s not the method for me.
Regardless of skill level, the pitch gauge
can offer great information that will help
monitor the amount of pitch in the blades.
This way, I know if the design limits are
exceeded and whether or not the amount of
pitch a specific engine can handle is
delivered.
If your helicopter’s head mechanics are
adjustable (programmable), changes to the
linkage geometry can be gauged with a
measuring tool such as a pitch gauge. Keep
a log of the readings; in the event of a
mishap, the helicopter can be returned to
those settings after the rebuild.
Caliper: A mechanical or digital caliper is
an invaluable tool for building, maintenance,
and/or repair. This device can be used to
ensure equal measurements on multiple
links and identify other points on the
helicopter that need to be equal on each
side.
Calipers are also ideal for identifying
measurements called out in the instruction
manual and for verifying correctness or
deviation of the actual assembly. It takes
out the guesswork.
With the flybar, the rod needs to be
centered within the assembly. A caliper
makes it easy to compare both sides without
having to squint to look at the fine lines of a
precision metric ruler.
Frame: When it comes to frame assembly,
the majority, if not all, of the kits self-align
during assembly. That is extraordinarily
helpful for the experienced pilot who is
working quickly to get a machine back in
the air, and it is especially helpful to the
new pilot who is starting out in this hobby.
Assemble the frame with the main shaft
temporarily installed inside the main
bearings. While tightening the bearingblock
screws, check periodically to make
sure that the shaft freely slips up and down.
A tight fit indicates misalignment or merely
a set of mounting screws that are tightened
more or less than the others; either is easy to
fix.
The essential thing is the servo locations
and proper servo-horn alignment. Assign
and locate servo arms once they have been
neutralized with both transmitter sticks in
the center (throttle at the halfway point).
Follow the instructions and set the servo
arms so that they align with the frame/case
as directed. Servo-arm length is critical as
well, so be diligent. Variations will cause
unwanted control input mixing.
Most servo arms are located with the
arm 90° of the servo case. This directive in
a setup system is commonly referred to as
“The Rule of 90.”
A servo arm and linkage system that is
90° relative to a specific pivot point will
deliver equal throw on either side. All
helicopters demand that equal throw at
least be available for the system’s
mechanics to operate correctly.
Engines: Engine technology has improved
tremendously, and that includes advances
in power, smoother throttle response, and,
thanks to new carburetor designs, more
reliability and stronger fuel-delivery
capabilities. In addition, the power plants
cool better overall, promoting longer life.
However, despite all of this, care is
necessary to keep engines running well. I
recommend a random check on the
mounting bolts or screws, since these
points are subjected to stress and vibration
every time the helicopter is flown.
Another area of the engine you should
inspect is the glow plug. Many of us don’t
change one of these until we learn that it is
no longer working—either during start-up
or, worse, during flight. The latter can be
costly if your machine is in a position
from which it won’t recover gracefully.
Check the glow plug on a regular basis,
and replace it if at all suspect of fault. The
average cost for a good plug is $5. That’s
certainly better than paying for costly
replacement parts.
Helicopter fuel is known to have more
oil and nitromethane content, to promote
better performance and cooling. Our
engines will run on airplane fuel, but they
may not last as long or be as reliable. Why
chance it?
Spending a few extra bucks on the right
fuel will pay you back later. You won’t be
sorry; use “helicopter”-specified fuel.
Tail and Tailboom: Model helicopters
have either a carbon fiber or aluminum
tailboom. Good tailboom supports offer
stability and prevent distortion.
Make sure that your machine’s
tailboom supports are fastened well.
Assemble them with an epoxy such as J.B.
Weld, to prevent the mounting lugs from
separating from the support material.
Include these mounting points during a
routine preflight check or a once-over
after a hard landing. Look for any
fractures or cracks, and make sure that the
tailboom clamps are tightened properly;
don’t overtorque the mounting bolts.
You should also thoroughly inspect the
tail section, since the high speeds at which
the parts operate can create sudden
irregularities when fault occurs. Any
suspect vibration that you see or hear can
quickly cause such problems as drifting
or, worse, total failure and a crash.
The introduction of the open tail
gearbox design greatly helped RC
helicopter pilots with maintenance. It
made points such as the gear mesh much
easier to inspect and adjust if needed.
Open gearboxes don’t require
lubrication, but keep them as clean as
possible to prevent excessive wear. We
need to lubricate areas that have slide
bearings, such as the tail-rotor pitchcontrol
slider.
Regularly inspect any screws and
bolts—particularly setscrews. Where
metal-to-metal contact is made, treat the
machine threads with a thread-locking
compound. Refresh the compound
whenever a screw is retightened or
replaced. It works best on threads that are
free from lubricant.
Keep your helicopter manual handy at all
times. Even when disassembly is done
with the utmost care, reassembly can be
confusing. Having at least a part
explosion illustration is a comfort.
Incorrectly reassembling an assembly can
have disastrous consequences.
Thanks to improvements in materials
and helicopter design, we enjoy flying
more and worrying about our machines
less. They can take more flight
punishment and therefore hold up better in
a mishap.
If we do our part in inspecting and
maintaining our models, fellow RCers—
and especially the public audience—will
appreciate how we respect our hobby/
sport. That may convince more people to
get involved. MA
Andy Panoncillo
[email protected]
Edition: Model Aviation - 2009/06
Page Numbers: 49,50,51,52,54,56
June 2009 49
THE HELICOPTER HAS
become one of the most
popular RC interests on the
market because of the
emergence of numerous
affordable and easy-to-build
kits. Many kits are designed
to be set up in a way that
allows beginners to learn and
progress with them as
advanced flying skills are
acquired.
These pilots can fly the
same helicopter from training
gear to 3-D, if they choose,
by making minor mechanical
adjustments or installing a
few upgrades. All the while,
they can fly a machine that is
safe and reliable—as long as
they follow the assembly and
maintenance tips I’m going to
cover.
Regardless of whether it is
a helicopter, airplane, glider, etc., aircraft
need attention before you take them out to
the field—especially if you’re going to a
fun-fly, where many people are either going
to be watching you or flying beside you.
Good maintenance also protects the
investment; some machines out there cost
their owners fairly good amounts of cash.
The modern RC helicopter is much
easier to build, set up, and maintain than
older versions. This is because they have
fewer parts, they self-align during
assembly, and they have factory-balanced
components, which makes the spinning
parts operate more smoothly, causing less
overall stress on the airframe.
by
Andy
Panoncillo
No matter how
complex the
machine, good
maintenance
practices can
ensure the
success of any
project.
06sig2.QXD 4/22/09 10:50 AM Page 49
50 MODEL AVIATION
Ball-link pliers, wire cutters, needle-nose pliers, and c-clip pliers
are just a few essentials of helicopter maintenance.
Some wrenches have special functions other than the obvious. The
Align types have a cavity that can store bolts, nuts, or spare tips.
Above: A simple caliper can make your build or maintenance
easy and accurate. A digital caliper is extremely handy, for
those who don’t mind the extra cost.
Right: Regularly inspect main and tail blades. Insects can load up
quickly on their LEs. Look carefully for nicks and cracks.
Keep the model organized by assigning fueltank
lines specific colors. Zip ties and doublestick
foam tape bind loose items so they don’t
come to harm.
Socket wrenches come in all shapes; these
are good for 30-size and larger helicopters.
Metric sizes from 4mm to 14mm are typically
useful.
Engine service requires a crankshaft
lock or piston lock (foreground).
Correctly tightening the fan/clutch
assembly would be impossible
without one.
Photos by the author
Keeping a good-running starter and battery
prevents hassles at the field when you’re
ready to fly your aircraft. A 4S Li-Poly battery
is used here.
06sig2.QXD 4/22/09 10:51 AM Page 50
June 2009 51
The fact that a helicopter has many moving parts dictates a
degree of fanaticism regarding equipment installation. Neatness
counts and can prevent heartache later.
Whether electric- or glow-powered, a secure canopy will help
streamline the machine and keep equipment as clean as possible.
Left: At midstick on the
transmitter, the swashplate
and lever should be level.
The servo arms should be
set up for equal throw on
each side of the midstick
point.
Right: Some pilots no longer
use a pitch gauge, and it works
for them. I recommend one to
monitor the amount of pitch,
to assure that the mechanics
are within limits.
Above: Keep an eye on the bottom for
excessive wear on struts and skids.
Silicone-rubber bumpers are available to
protect landing gear.
Right: This model’s wiring is mostly
hidden on the inside of the frame. Nice!
Electrics rarely get dirty, but they should
be inspected as frequently as enginepowered
aircraft.
06sig2.QXD 4/22/09 10:18 AM Page 51
Even smaller 400-class machines need regular maintenance. Tug on the ball
links now and then to check for security.
52 MODEL AVIATION
While a helicopter is transported, bouncing can wear on its
mechanics unless a simple blade holder is used.
Whether the helicopter tail control is driven by a belt or torque
tube, make sure that the bearings are properly lubricated and
cleaned to prevent any chance of binding.
A good fuel filter ensures that clean fuel will
get to the engine, prolonging its life and
ensuring that optimal power can be
achieved.
The requirement for special tools to
maintain an RC helicopter is behind us,
but we still need some essential devices to
keep our machines operating well. You
can find these tools in the average flight
box.
Head Assembly: This is where most of
the work happens in terms of setup and
maintenance. That is especially true now
that many head-design assemblies include
programmable linkage features that allow
the sensitivity to be customized to suit a
specific taste or flying style.
A gadget that I fully recommend is a
swashplate leveling tool. Using it the right
way eliminates most problems with a
helicopter’s trimming in terms of control
interaction. Not only will this instrument
indicate a neutral state, but it will also
clearly show when the servos are causing
unwanted input that can often occur in
CCPM (Cyclic/Collective Pitch Mixing)
mechanics.
For instance, if right cyclic also inputs
aft cyclic, this requires the pilot to input
forward control when only roll input is
enacted with movement of the transmitter
gimbal. It’s like flying a model that is
constantly out of trim.
You can purchase a swashplate leveling
tool from a Web site or hobby shop that
06sig2.QXD 4/22/09 10:18 AM Page 52
handles RC helicopters. This device can
be used for the majority of helicopter sizes,
from 30 to 90. If you have a 450-size
model, you’ll need the smallest swashplate
leveler.
Use the leveling tool to identify
interactions on the bench. Adjustments
can be made mechanically or with a
program mix in the radio. Most
interactions can be detected while testing
the collective pitch control; watch the
bubbles as the swashplate moves up and
down.
Off-center indications will identify
early what servo or linkage needs
tweaking. It’s well worth the effort,
because your machine will fly practically
perfect on its first hop.
Ball Links: These are the primary
connection between all of the model’s
mechanics. They should fit securely but
move freely.
A tight link offers security, but its
binding can prevent mechanics from
recentering or operating at their full
potential. A machine with tight links will
eventually break in, but it might be extra
work for the pilot to operate until then.
A ball-link sizing tool will condition
any linkages that are too tight on their ball
ends. Use this instrument sparingly; an
oversized linkage won’t stay attached and
will be less precise and more dangerous to
operate.
Links are inexpensive, so buy a pack and
have it handy for replacement in case a
preflight reveals a faulty area.
Pitch Gauge: With enough experience,
some pilots avoid using a pitch gauge.
They’re either not picky or figure that
flight-testing will reveal any issues and
correct them later.
That’s not the method for me.
Regardless of skill level, the pitch gauge
can offer great information that will help
monitor the amount of pitch in the blades.
This way, I know if the design limits are
exceeded and whether or not the amount of
pitch a specific engine can handle is
delivered.
If your helicopter’s head mechanics are
adjustable (programmable), changes to the
linkage geometry can be gauged with a
measuring tool such as a pitch gauge. Keep
a log of the readings; in the event of a
mishap, the helicopter can be returned to
those settings after the rebuild.
Caliper: A mechanical or digital caliper is
an invaluable tool for building, maintenance,
and/or repair. This device can be used to
ensure equal measurements on multiple
links and identify other points on the
helicopter that need to be equal on each
side.
Calipers are also ideal for identifying
measurements called out in the instruction
manual and for verifying correctness or
deviation of the actual assembly. It takes
out the guesswork.
With the flybar, the rod needs to be
centered within the assembly. A caliper
makes it easy to compare both sides without
having to squint to look at the fine lines of a
precision metric ruler.
Frame: When it comes to frame assembly,
the majority, if not all, of the kits self-align
during assembly. That is extraordinarily
helpful for the experienced pilot who is
working quickly to get a machine back in
the air, and it is especially helpful to the
new pilot who is starting out in this hobby.
Assemble the frame with the main shaft
temporarily installed inside the main
bearings. While tightening the bearingblock
screws, check periodically to make
sure that the shaft freely slips up and down.
A tight fit indicates misalignment or merely
a set of mounting screws that are tightened
more or less than the others; either is easy to
fix.
The essential thing is the servo locations
and proper servo-horn alignment. Assign
and locate servo arms once they have been
neutralized with both transmitter sticks in
the center (throttle at the halfway point).
Follow the instructions and set the servo
arms so that they align with the frame/case
as directed. Servo-arm length is critical as
well, so be diligent. Variations will cause
unwanted control input mixing.
Most servo arms are located with the
arm 90° of the servo case. This directive in
a setup system is commonly referred to as
“The Rule of 90.”
A servo arm and linkage system that is
90° relative to a specific pivot point will
deliver equal throw on either side. All
helicopters demand that equal throw at
least be available for the system’s
mechanics to operate correctly.
Engines: Engine technology has improved
tremendously, and that includes advances
in power, smoother throttle response, and,
thanks to new carburetor designs, more
reliability and stronger fuel-delivery
capabilities. In addition, the power plants
cool better overall, promoting longer life.
However, despite all of this, care is
necessary to keep engines running well. I
recommend a random check on the
mounting bolts or screws, since these
points are subjected to stress and vibration
every time the helicopter is flown.
Another area of the engine you should
inspect is the glow plug. Many of us don’t
change one of these until we learn that it is
no longer working—either during start-up
or, worse, during flight. The latter can be
costly if your machine is in a position
from which it won’t recover gracefully.
Check the glow plug on a regular basis,
and replace it if at all suspect of fault. The
average cost for a good plug is $5. That’s
certainly better than paying for costly
replacement parts.
Helicopter fuel is known to have more
oil and nitromethane content, to promote
better performance and cooling. Our
engines will run on airplane fuel, but they
may not last as long or be as reliable. Why
chance it?
Spending a few extra bucks on the right
fuel will pay you back later. You won’t be
sorry; use “helicopter”-specified fuel.
Tail and Tailboom: Model helicopters
have either a carbon fiber or aluminum
tailboom. Good tailboom supports offer
stability and prevent distortion.
Make sure that your machine’s
tailboom supports are fastened well.
Assemble them with an epoxy such as J.B.
Weld, to prevent the mounting lugs from
separating from the support material.
Include these mounting points during a
routine preflight check or a once-over
after a hard landing. Look for any
fractures or cracks, and make sure that the
tailboom clamps are tightened properly;
don’t overtorque the mounting bolts.
You should also thoroughly inspect the
tail section, since the high speeds at which
the parts operate can create sudden
irregularities when fault occurs. Any
suspect vibration that you see or hear can
quickly cause such problems as drifting
or, worse, total failure and a crash.
The introduction of the open tail
gearbox design greatly helped RC
helicopter pilots with maintenance. It
made points such as the gear mesh much
easier to inspect and adjust if needed.
Open gearboxes don’t require
lubrication, but keep them as clean as
possible to prevent excessive wear. We
need to lubricate areas that have slide
bearings, such as the tail-rotor pitchcontrol
slider.
Regularly inspect any screws and
bolts—particularly setscrews. Where
metal-to-metal contact is made, treat the
machine threads with a thread-locking
compound. Refresh the compound
whenever a screw is retightened or
replaced. It works best on threads that are
free from lubricant.
Keep your helicopter manual handy at all
times. Even when disassembly is done
with the utmost care, reassembly can be
confusing. Having at least a part
explosion illustration is a comfort.
Incorrectly reassembling an assembly can
have disastrous consequences.
Thanks to improvements in materials
and helicopter design, we enjoy flying
more and worrying about our machines
less. They can take more flight
punishment and therefore hold up better in
a mishap.
If we do our part in inspecting and
maintaining our models, fellow RCers—
and especially the public audience—will
appreciate how we respect our hobby/
sport. That may convince more people to
get involved. MA
Andy Panoncillo
[email protected]