A guest helicopter review by Gordie Meade
[[email protected]]
Radio Control Helicopters Ray Stacy
ONE OF THE things I love about this
hobby is the variety. From electric to gas
power, there are many models available.
One of my goals for this column is to share
as much information as possible about as
many different helicopters as possible.
There is no way I can fly every machine,
so I rely on friends I have made throughout
the years to share their knowledge with us.
Gordie Meade is one of those people. He is
a longtime FAI F3C pilot, but, more
important, he is a straight shooter with an
honest opinion.
Gordie contacted me a few months ago
and said he would like to review the X-Cell
Stratus. I am impressed with his work; he
gave me such a detailed report that I need to
present it in two parts. Following is the first
portion; I think you will enjoy it.
“A few months back I decided I needed
a new model for the upcoming FAI contest
season. For 2006, the FAI F3C schedules
have been revised and the new schedules
require a slightly different style of model.
“The model needs a faster roll rate than
we have chosen to run in the past, there are
some outside pushes and inverted work, and hovering has been deemphasized,
so a lighter model seems to be a step toward the
‘solution.’
“For the past six or seven years I have flown the XL Pro, starting
with the early XL Pro I and ending with the last, the XL Pro IIK-T. I
loved the way my Pros hovered and flew and had a great deal of
success with them, but they had pretty much reached the end of their
development, because there just wasn’t much left that could be done
to improve the model any further.
“It weighed 11.5 pounds ready to fly, less fuel, and had a very
complex though efficient control system that was pretty much
interaction free but required regular routine maintenance to keep
accurate and slop free.
“I have flown all the Miniature Aircraft eCCPM Fury series,
having owned at one time or another a Fury Expert, several Fury
X-Cell Stratus kit contents with E-documentation loaded on the laptop. If you prefer a
hard-copy manual, Miniature Aircraft will send it to you.
New for the Stratus is this FAI head assembly.
The main shaft is supported by four bearings! Miniature Aircraft is
believed to be the only manufacturer to do this.
Note the Gear Ratio Adapter Plates in the starting-block area. A
plate for each gear ratio helps make alignment and mesh
adjustment easy.
July 2006 117
I got in touch with Miniature Aircraft
and ordered a Stratus conversion for my
Tempest FAI. Since the change in the
model was basically just a frame change, I
had the Stratus conversion ready to fly in a
comparatively short time.
“The model, ready to fly with the
Tempest FAI rotor head, the open tail-rotor
gearbox, 45-gram flybar paddles, YS .91
with Hatori SB16FH muffler, and 205-gram
symmetrical 720mm blades, weighed in at
10 pounds, 2 ounces—a stunning loss of a
pound and a half off my Nats FAI XL Pro
IIK-T. And as a bonus, the tank is rear
mounted on the Stratus versus front
mounted on the Fury and Tempest for a
more consistent center of gravity as the fuel
burns off.
“Most of the seriously competitive fliers
I know will tell you that in order to be ready
to seriously compete in FAI F3C, you need
to have two identical models ready to fly so
that if you run into a minor problem and
need to go to your back-up model, it’s very similar in performance
to your primary model. It also means you can split practice time
among two or three models and not put so much wear on a single
model, so it will last much longer before needing a rebuild.
“Since I had already decided to go with the Stratus for the 2006
season, I needed a second model. I placed a call to the Stratus
designer, Tim Schoonard, at Miniature Aircraft USA in Sorrento,
Florida, discussed my specific needs, and placed my order for a full
Stratus FAI kit. The Stratus kit comes in four varieties based on the
style of flying you want and the engine you opt to use.
“For the 3-D flier, the Stratus 3D kit for use with the O.S. .91
comes with an 8:18 gear ratio or for the YS .91 comes with an 8:45
gear ratio. For F3C, the Stratus FAI using the O.S. .91 comes with a
7:75 gear ratio and for the YS .91 comes with the 7:91 gear ratio.
“I have used the YS .91 with the 7:91 gear ratio in my
competition XL Pro IIs for several years and found the combination
to be smooth and fuel efficient in hover and to have excellent
straight-line speed in forward flight.
“From that experience, I selected the #1026-4 FAI Stratus with
the 7:91 gear ratio for the YS .91 and a short time later the ‘Little
Brown Helicopter Truck’ pulled up in front of the house and the
driver brought me a great big box. Upon opening the big shipping
box, I found inside a nicely packed kit box.
“The kit box is factory sealed, so the buyer can tell if the kit has
been opened, and each kit has its own unique serial number. If you
register the model with Miniature Aircraft, you will be kept
informed of updates and new information about the model as it
becomes available.
“I found the contents to be well protected and all machined and
plastic parts to be shrink-wrapped in plastic. The fiberglass canopyExtremes, and a Tempest FAI. When the Stratus conversions
became available, I was thinking about converting my Tempest FAI
to Stratus FAI to try the new frame configuration. Nearly at the
same time the Futaba 14MZ radio system became available and the
combination of the two, in my mind, made eCCPM workable for
F3C.
“My Fury Expert has flown with YS .61s, YS .80s, and now has
a YS .91 installed. I always loved the power of the control system
and the simplicity of the model, but it always had a little control
interaction at extremes of throw and for FAI that is really a major
problem.
“In my 9Z, I had several program mixes in place to fix the
majority of the interactions but always found that the servos changed
slightly over time and it was constantly necessary to ‘tweak’ the
mixes to keep the model neutral. I was never actually sure whether
the little ‘funnies’ I was getting periodically in flight were the result
of control interaction in the model or just poor piloting.
“The Tempest FAI had improved control geometry but still had
the forward-mounted tank and a very tall profile. I had flown the
Tempest the previous year and liked it but did not consider it to be a
quantum leap forward, but just a necessary evolutionary step.
“The 14MZ, with its advanced eCCPM program, made the
Stratus and other eCCPM models very workable for F3C. After
watching the Stratus 3D performing some outrageous extreme 3-D, I
spoke to Eric Larson and a couple of other pilots who were flying
the new Stratus, and they were very pleased with their models,
which exhibited amazing agility and performance, more so than any
of their previous models.
“Eric told me his model with an O.S. .91 weighed right around
10 pounds and the model’s amazing performance was directly
is in a separate area of the box, protected from shifting contents andon the engine are now extended through a
carbon-fiber baseplate as the primary engine
mount. There are smaller stabilizer mounts
that bolt to the engine’s normal mounting
lugs, and the whole subassembly bolts to the
baseplate of the model and is adjustable for
engine to clutch alignment. The net result is
a very open, uncluttered engine area with
good access to all engine components and
needles.
“Since I am using the YS .91, I borrowed
an idea from F3C pilot Dennis Purduski and
drilled and tapped two holes for long ball
links into the lower main baseplate. Instead
of plugging and unplugging fuel lines every
flight, I use a T fitting in both the fuel and
pressure lines and use these ball links as
plugs.
“This makes for a very nice, neat fuel
system, and you can vent the fuel tank after
a flight by pulling the vent line easily off the
ball link using only one hand, which
prevents the engine from flooding between
flights, and it keeps the fuel system neatly
out of the way. It’s really easy to do while
the model is in construction and saves a lot
of effort when preparing for a contest flight.
“Also I use different color fuel line for
different applications. On all my models,
fuel line is green, pressure line is yellow, so
I never get confused and pull the wrong one
and spray myself with fuel while trying to
vent the tank.
“You will also notice that I use very
short landing gear skids. The kit comes with
the standard X-Cell Tuff Struts, which are
very good, but for several years I have been
using the standard white Tuff Struts with the
X-Cell 30 skids. They are the same outside
diameter and fit the struts perfectly but are
shorter and lighter in weight.
“Since an FAI model is required to land
in a 1-meter circle, the smaller footprint of
the shorter skids gives just a little more
margin for error. Plus I think they look nice,
smaller, and more compact. I cannot tell any
trim difference in forward flight
performance, but I like the profile of the
smaller skids when in hover.
“I spent quite a bit of time getting the
cooling fan balanced and aligned on the
engine. The Stratus FAI comes with the XCell
machined aluminum fan which comes
pretty well balanced, but I always put a GV-1is currently the same canopy the Tempest
uses. My kit still has the interim fuel tank,
which will eventually be replaced by a
custom molded tank.
“The assembly instructions come on a
CD as an Adobe PDF file and require the
use of Adobe reader, which is a free
download on the Internet. Since there is no
printed main manual, assembly requires a
little creative thinking.
“The construction manual is lengthy at
186 pages, plus there is a separate printed
manual for the Tempest FAI rotor head. You
can take the CD to a print/copy place like
Kinko’s and have a hard copy made if you
want to have it available for bench
reference. Since I have a laptop computer, I
can place the laptop on my building table
and look at the pictures, read the
instructions, and build at the same time.
“The manual is full of pictures and each
part has its own identification picture, and
then the model is shown in stages of
assembly. Adobe reader has a built-in
magnifier so you can blow the pictures up to
200% if you want to see details. Every bolt
is identified by its size and length and is
shown both separately and installed in the
assembly.
“As with all the Miniature Aircraft
models, the Stratus goes together in
subassemblies, the lower main frames, the
upper main frames, the head, the tail rotor,
and so on. Each subassembly comes in a
bag, and within the main bag are smaller
bags with identification labels, which are in
alphabetical order of their use. Start with
Bag 1A, 1B, etc., follow the assembly
instructions until you run out of bags, and
you have a finished model.
“The Stratus differs from most current
model designs in one major way: the way
the engine is mounted to the lower main
frames. Most models, including the other
Miniature Aircraft glow designs, have a
machined aluminum engine mount that bolts
to the main frames and the mounting lugs on
the engine. The Stratus uses the engine as an
integral part of the frame.
“The same bolts that hold the backplatemagnet in the fan even if I don’t plan on
using a governor since I may change my
mind and it’s a pain to install the magnet
later.
“When everything is new and clean,
installing the magnet is easy but does require
that you rebalance the fan. I have been using
the Top Flite magnetic prop balancer for
quite awhile to balance my fans and have
had a lot of success. It took me about 15
minutes of testing the fan, drilling a dimple
to remove weight from the heavy side,
retesting, redrilling, until the fan would stop
randomly and would stay in any position it
was placed.
“If you are planning on using an optical
sensor, I’d suggest painting the bottom of
the fan flat black except for a 1/2-inch strip
which is left natural aluminum color and
again rebalance the fan after painting by
drilling a dimple or two on the top of the fan
between the fins on the heavy side.
“After flying F3C for a lot of years now,
I always want my fans aligned on the
crankshaft of the motor with a runout of less
than .001 inch. I have over the years tried
about 40 methods of doing this and find
some ways are better than others, but none I
have ever tried is fool-proof.
“For the Stratus, I used a method I got
from Ben Minor that requires tapping the fan
with a plastic hammer while supporting the
back of the crankshaft with a large wooden
dowel to keep load off the bearings and
engine case and gradually tightening the fan.
“It’s pretty easy to do if there are two
people but a lot tougher when you are
working alone, and it took me about an hour
and a half to get the fan aligned within +/-
.0005 inch, which makes the total runout
less than .001 inch which should be good.
“The instructions say to put oil on the
collets and spread it around to keep the fan
from binding to the collets while tightening.
I found a Permatex product called Antiseize
Lubricant in a little squeeze tube at the local
auto parts store that works even better and
makes the fan more easily removable if you
need to pull it to do engine work or
something. It works great.
“If you ever get a fan balanced and on an
engine with a zero runout, the model
achieves a state of ‘creaminess’ in flight that
has to be felt to be appreciated. Creaminess
is a term I picked up from Wayne Mann to
describe a model that is mechanically really
good. The engine drones smoothly, the
mechanics are smooth and quiet, and the
model just sits in a hover and hums. It’s hard
to describe in words, but once you see and
hear it, there is no doubt in your mind when
a model is doing it.
“If you elect to use one of the new O.S.
.91 SZs, it has a slightly different dimension
than either the YS .91 or the O.S. .91 CSpec,
and it does require a different collet
set, mounting screws, and baseplate.
Miniature has those parts in stock and can
supply them to you.
“The next assembly is the upper main
frames, and Miniature has come up with a
really great idea here. Everything is
assembled on one side of the upper frames,
which allows easy access to bearing blocks
for alignment. All three main shaft support
bearing blocks are loosely installed and the
main shaft inserted, and then each block is
tightened in place. The blocks are all aligned
with the main shaft and there is no binding.
“The main gear and retaining collars are
all installed and the tail rotor drive gear
mesh is set while everything is easily
AMA Academy of Model
Aeronautics
ARF Almost Ready to Fly
BEC Battery Eliminator Circuit
CAD computer-aided design
cc cubic centimeter
CD contest director or
compact disc
CG center of gravity
CL Control Line
cm centimeter
cu. in. cubic inch
DT dethermalizer
EPP (foam) expanded polypropylene
ESC Electronic Speed Control
FAI Fédération Aéronautique
Internationale
FCC Federal Communications
Commission
FF Free Flight
LCD Liquid Crystal Display
LE leading edge
LED light-emitting diode
Li-Poly Lithium Polymer
mA milliamperes
MA Model Aviation
mAh milliampere-hours
MHz megahertz
mm millimeter
Nats AMA Nationals
Ni-Cd Nickel Cadmium
NiMH Nickel Metal Hydride
RC Radio Control
rpm revolutions per minute
RTF Ready to Fly
SASE self-addressed, stamped
envelope
SIG Special Interest Group
TE trailing edge
ModelAviation’s Frequently Used
Abbreviations/Acronyms
accessible. The clutch is also installed and
aligned to the main gear while it is out in
the open and you are able to move it freely.
When everything is installed and
functioning smoothly, the other side is
bolted on and the upper frames are
completed.
“I do a couple of things differently from
the kit instructions. I use a tailboommounted
tail-rotor servo instead of the
frame-mounted servo that goes through a
bellcrank that comes with the kit. By
mounting the servo on the boom, I am able
to place my gyro sensor in the hole where
the tail rotor servo is supposed to be and get
the sensor farther away from the engine and
start shaft assembly with its inherent
vibration. I find I get a little better gyro
performance by doing that. Miniature has a
conversion to do it already made up: part
#126-85.
“The Stratus FAI comes with the new
open tail rotor gearbox which has the 4.7:1
tail rotor gear ratio, that gives you plenty of
authority when used in conjunction with the
105mm tail rotor blades. The gearbox is
preassembled and requires only the
installation of the pitch slider and hub to
complete tail rotor assembly.
“I elected to use the Miniature Aircraft
metal tail rotor grips, which are very nice
and eliminate some of the associated free
play of the plastic parts. I found that I could
use an old 10mm main shaft to push the first
thrust bearing race into position easily and
without the chance of damaging the bearing.
“When bolted up correctly, they give
excellent performance and remain very tight
and slop free for extended periods, which is
also a plus for an FAI model. I am currently
using the new Youngblood Radix 105mm
tail rotor blades that are very stiff and
torsionally rigid.
“I find I can run lower tail rotor
deflection and still get the necessary spin
rates to do a clean 540° stall turn with a nice
precise stop at the end. Balance and CG of
the tail rotor blades was very good right out
of the package and required no additional
balancing. I have used several other types of
tail rotor blades also and most work fine.
Make sure the weight and balance are
correct and it will work.”
Sorry; I know I’m leaving you hanging,
but that’s all the space I’m allowed to use
right now. That machine sounds hot,
doesn’t it? Come back next month to see
how the Stratus FAI finished up and
Edition: Model Aviation - 2006/07
Page Numbers: 117,118,120,122
Edition: Model Aviation - 2006/07
Page Numbers: 117,118,120,122
A guest helicopter review by Gordie Meade
[[email protected]]
Radio Control Helicopters Ray Stacy
ONE OF THE things I love about this
hobby is the variety. From electric to gas
power, there are many models available.
One of my goals for this column is to share
as much information as possible about as
many different helicopters as possible.
There is no way I can fly every machine,
so I rely on friends I have made throughout
the years to share their knowledge with us.
Gordie Meade is one of those people. He is
a longtime FAI F3C pilot, but, more
important, he is a straight shooter with an
honest opinion.
Gordie contacted me a few months ago
and said he would like to review the X-Cell
Stratus. I am impressed with his work; he
gave me such a detailed report that I need to
present it in two parts. Following is the first
portion; I think you will enjoy it.
“A few months back I decided I needed
a new model for the upcoming FAI contest
season. For 2006, the FAI F3C schedules
have been revised and the new schedules
require a slightly different style of model.
“The model needs a faster roll rate than
we have chosen to run in the past, there are
some outside pushes and inverted work, and hovering has been deemphasized,
so a lighter model seems to be a step toward the
‘solution.’
“For the past six or seven years I have flown the XL Pro, starting
with the early XL Pro I and ending with the last, the XL Pro IIK-T. I
loved the way my Pros hovered and flew and had a great deal of
success with them, but they had pretty much reached the end of their
development, because there just wasn’t much left that could be done
to improve the model any further.
“It weighed 11.5 pounds ready to fly, less fuel, and had a very
complex though efficient control system that was pretty much
interaction free but required regular routine maintenance to keep
accurate and slop free.
“I have flown all the Miniature Aircraft eCCPM Fury series,
having owned at one time or another a Fury Expert, several Fury
X-Cell Stratus kit contents with E-documentation loaded on the laptop. If you prefer a
hard-copy manual, Miniature Aircraft will send it to you.
New for the Stratus is this FAI head assembly.
The main shaft is supported by four bearings! Miniature Aircraft is
believed to be the only manufacturer to do this.
Note the Gear Ratio Adapter Plates in the starting-block area. A
plate for each gear ratio helps make alignment and mesh
adjustment easy.
July 2006 117
I got in touch with Miniature Aircraft
and ordered a Stratus conversion for my
Tempest FAI. Since the change in the
model was basically just a frame change, I
had the Stratus conversion ready to fly in a
comparatively short time.
“The model, ready to fly with the
Tempest FAI rotor head, the open tail-rotor
gearbox, 45-gram flybar paddles, YS .91
with Hatori SB16FH muffler, and 205-gram
symmetrical 720mm blades, weighed in at
10 pounds, 2 ounces—a stunning loss of a
pound and a half off my Nats FAI XL Pro
IIK-T. And as a bonus, the tank is rear
mounted on the Stratus versus front
mounted on the Fury and Tempest for a
more consistent center of gravity as the fuel
burns off.
“Most of the seriously competitive fliers
I know will tell you that in order to be ready
to seriously compete in FAI F3C, you need
to have two identical models ready to fly so
that if you run into a minor problem and
need to go to your back-up model, it’s very similar in performance
to your primary model. It also means you can split practice time
among two or three models and not put so much wear on a single
model, so it will last much longer before needing a rebuild.
“Since I had already decided to go with the Stratus for the 2006
season, I needed a second model. I placed a call to the Stratus
designer, Tim Schoonard, at Miniature Aircraft USA in Sorrento,
Florida, discussed my specific needs, and placed my order for a full
Stratus FAI kit. The Stratus kit comes in four varieties based on the
style of flying you want and the engine you opt to use.
“For the 3-D flier, the Stratus 3D kit for use with the O.S. .91
comes with an 8:18 gear ratio or for the YS .91 comes with an 8:45
gear ratio. For F3C, the Stratus FAI using the O.S. .91 comes with a
7:75 gear ratio and for the YS .91 comes with the 7:91 gear ratio.
“I have used the YS .91 with the 7:91 gear ratio in my
competition XL Pro IIs for several years and found the combination
to be smooth and fuel efficient in hover and to have excellent
straight-line speed in forward flight.
“From that experience, I selected the #1026-4 FAI Stratus with
the 7:91 gear ratio for the YS .91 and a short time later the ‘Little
Brown Helicopter Truck’ pulled up in front of the house and the
driver brought me a great big box. Upon opening the big shipping
box, I found inside a nicely packed kit box.
“The kit box is factory sealed, so the buyer can tell if the kit has
been opened, and each kit has its own unique serial number. If you
register the model with Miniature Aircraft, you will be kept
informed of updates and new information about the model as it
becomes available.
“I found the contents to be well protected and all machined and
plastic parts to be shrink-wrapped in plastic. The fiberglass canopyExtremes, and a Tempest FAI. When the Stratus conversions
became available, I was thinking about converting my Tempest FAI
to Stratus FAI to try the new frame configuration. Nearly at the
same time the Futaba 14MZ radio system became available and the
combination of the two, in my mind, made eCCPM workable for
F3C.
“My Fury Expert has flown with YS .61s, YS .80s, and now has
a YS .91 installed. I always loved the power of the control system
and the simplicity of the model, but it always had a little control
interaction at extremes of throw and for FAI that is really a major
problem.
“In my 9Z, I had several program mixes in place to fix the
majority of the interactions but always found that the servos changed
slightly over time and it was constantly necessary to ‘tweak’ the
mixes to keep the model neutral. I was never actually sure whether
the little ‘funnies’ I was getting periodically in flight were the result
of control interaction in the model or just poor piloting.
“The Tempest FAI had improved control geometry but still had
the forward-mounted tank and a very tall profile. I had flown the
Tempest the previous year and liked it but did not consider it to be a
quantum leap forward, but just a necessary evolutionary step.
“The 14MZ, with its advanced eCCPM program, made the
Stratus and other eCCPM models very workable for F3C. After
watching the Stratus 3D performing some outrageous extreme 3-D, I
spoke to Eric Larson and a couple of other pilots who were flying
the new Stratus, and they were very pleased with their models,
which exhibited amazing agility and performance, more so than any
of their previous models.
“Eric told me his model with an O.S. .91 weighed right around
10 pounds and the model’s amazing performance was directly
is in a separate area of the box, protected from shifting contents andon the engine are now extended through a
carbon-fiber baseplate as the primary engine
mount. There are smaller stabilizer mounts
that bolt to the engine’s normal mounting
lugs, and the whole subassembly bolts to the
baseplate of the model and is adjustable for
engine to clutch alignment. The net result is
a very open, uncluttered engine area with
good access to all engine components and
needles.
“Since I am using the YS .91, I borrowed
an idea from F3C pilot Dennis Purduski and
drilled and tapped two holes for long ball
links into the lower main baseplate. Instead
of plugging and unplugging fuel lines every
flight, I use a T fitting in both the fuel and
pressure lines and use these ball links as
plugs.
“This makes for a very nice, neat fuel
system, and you can vent the fuel tank after
a flight by pulling the vent line easily off the
ball link using only one hand, which
prevents the engine from flooding between
flights, and it keeps the fuel system neatly
out of the way. It’s really easy to do while
the model is in construction and saves a lot
of effort when preparing for a contest flight.
“Also I use different color fuel line for
different applications. On all my models,
fuel line is green, pressure line is yellow, so
I never get confused and pull the wrong one
and spray myself with fuel while trying to
vent the tank.
“You will also notice that I use very
short landing gear skids. The kit comes with
the standard X-Cell Tuff Struts, which are
very good, but for several years I have been
using the standard white Tuff Struts with the
X-Cell 30 skids. They are the same outside
diameter and fit the struts perfectly but are
shorter and lighter in weight.
“Since an FAI model is required to land
in a 1-meter circle, the smaller footprint of
the shorter skids gives just a little more
margin for error. Plus I think they look nice,
smaller, and more compact. I cannot tell any
trim difference in forward flight
performance, but I like the profile of the
smaller skids when in hover.
“I spent quite a bit of time getting the
cooling fan balanced and aligned on the
engine. The Stratus FAI comes with the XCell
machined aluminum fan which comes
pretty well balanced, but I always put a GV-1is currently the same canopy the Tempest
uses. My kit still has the interim fuel tank,
which will eventually be replaced by a
custom molded tank.
“The assembly instructions come on a
CD as an Adobe PDF file and require the
use of Adobe reader, which is a free
download on the Internet. Since there is no
printed main manual, assembly requires a
little creative thinking.
“The construction manual is lengthy at
186 pages, plus there is a separate printed
manual for the Tempest FAI rotor head. You
can take the CD to a print/copy place like
Kinko’s and have a hard copy made if you
want to have it available for bench
reference. Since I have a laptop computer, I
can place the laptop on my building table
and look at the pictures, read the
instructions, and build at the same time.
“The manual is full of pictures and each
part has its own identification picture, and
then the model is shown in stages of
assembly. Adobe reader has a built-in
magnifier so you can blow the pictures up to
200% if you want to see details. Every bolt
is identified by its size and length and is
shown both separately and installed in the
assembly.
“As with all the Miniature Aircraft
models, the Stratus goes together in
subassemblies, the lower main frames, the
upper main frames, the head, the tail rotor,
and so on. Each subassembly comes in a
bag, and within the main bag are smaller
bags with identification labels, which are in
alphabetical order of their use. Start with
Bag 1A, 1B, etc., follow the assembly
instructions until you run out of bags, and
you have a finished model.
“The Stratus differs from most current
model designs in one major way: the way
the engine is mounted to the lower main
frames. Most models, including the other
Miniature Aircraft glow designs, have a
machined aluminum engine mount that bolts
to the main frames and the mounting lugs on
the engine. The Stratus uses the engine as an
integral part of the frame.
“The same bolts that hold the backplatemagnet in the fan even if I don’t plan on
using a governor since I may change my
mind and it’s a pain to install the magnet
later.
“When everything is new and clean,
installing the magnet is easy but does require
that you rebalance the fan. I have been using
the Top Flite magnetic prop balancer for
quite awhile to balance my fans and have
had a lot of success. It took me about 15
minutes of testing the fan, drilling a dimple
to remove weight from the heavy side,
retesting, redrilling, until the fan would stop
randomly and would stay in any position it
was placed.
“If you are planning on using an optical
sensor, I’d suggest painting the bottom of
the fan flat black except for a 1/2-inch strip
which is left natural aluminum color and
again rebalance the fan after painting by
drilling a dimple or two on the top of the fan
between the fins on the heavy side.
“After flying F3C for a lot of years now,
I always want my fans aligned on the
crankshaft of the motor with a runout of less
than .001 inch. I have over the years tried
about 40 methods of doing this and find
some ways are better than others, but none I
have ever tried is fool-proof.
“For the Stratus, I used a method I got
from Ben Minor that requires tapping the fan
with a plastic hammer while supporting the
back of the crankshaft with a large wooden
dowel to keep load off the bearings and
engine case and gradually tightening the fan.
“It’s pretty easy to do if there are two
people but a lot tougher when you are
working alone, and it took me about an hour
and a half to get the fan aligned within +/-
.0005 inch, which makes the total runout
less than .001 inch which should be good.
“The instructions say to put oil on the
collets and spread it around to keep the fan
from binding to the collets while tightening.
I found a Permatex product called Antiseize
Lubricant in a little squeeze tube at the local
auto parts store that works even better and
makes the fan more easily removable if you
need to pull it to do engine work or
something. It works great.
“If you ever get a fan balanced and on an
engine with a zero runout, the model
achieves a state of ‘creaminess’ in flight that
has to be felt to be appreciated. Creaminess
is a term I picked up from Wayne Mann to
describe a model that is mechanically really
good. The engine drones smoothly, the
mechanics are smooth and quiet, and the
model just sits in a hover and hums. It’s hard
to describe in words, but once you see and
hear it, there is no doubt in your mind when
a model is doing it.
“If you elect to use one of the new O.S.
.91 SZs, it has a slightly different dimension
than either the YS .91 or the O.S. .91 CSpec,
and it does require a different collet
set, mounting screws, and baseplate.
Miniature has those parts in stock and can
supply them to you.
“The next assembly is the upper main
frames, and Miniature has come up with a
really great idea here. Everything is
assembled on one side of the upper frames,
which allows easy access to bearing blocks
for alignment. All three main shaft support
bearing blocks are loosely installed and the
main shaft inserted, and then each block is
tightened in place. The blocks are all aligned
with the main shaft and there is no binding.
“The main gear and retaining collars are
all installed and the tail rotor drive gear
mesh is set while everything is easily
AMA Academy of Model
Aeronautics
ARF Almost Ready to Fly
BEC Battery Eliminator Circuit
CAD computer-aided design
cc cubic centimeter
CD contest director or
compact disc
CG center of gravity
CL Control Line
cm centimeter
cu. in. cubic inch
DT dethermalizer
EPP (foam) expanded polypropylene
ESC Electronic Speed Control
FAI Fédération Aéronautique
Internationale
FCC Federal Communications
Commission
FF Free Flight
LCD Liquid Crystal Display
LE leading edge
LED light-emitting diode
Li-Poly Lithium Polymer
mA milliamperes
MA Model Aviation
mAh milliampere-hours
MHz megahertz
mm millimeter
Nats AMA Nationals
Ni-Cd Nickel Cadmium
NiMH Nickel Metal Hydride
RC Radio Control
rpm revolutions per minute
RTF Ready to Fly
SASE self-addressed, stamped
envelope
SIG Special Interest Group
TE trailing edge
ModelAviation’s Frequently Used
Abbreviations/Acronyms
accessible. The clutch is also installed and
aligned to the main gear while it is out in
the open and you are able to move it freely.
When everything is installed and
functioning smoothly, the other side is
bolted on and the upper frames are
completed.
“I do a couple of things differently from
the kit instructions. I use a tailboommounted
tail-rotor servo instead of the
frame-mounted servo that goes through a
bellcrank that comes with the kit. By
mounting the servo on the boom, I am able
to place my gyro sensor in the hole where
the tail rotor servo is supposed to be and get
the sensor farther away from the engine and
start shaft assembly with its inherent
vibration. I find I get a little better gyro
performance by doing that. Miniature has a
conversion to do it already made up: part
#126-85.
“The Stratus FAI comes with the new
open tail rotor gearbox which has the 4.7:1
tail rotor gear ratio, that gives you plenty of
authority when used in conjunction with the
105mm tail rotor blades. The gearbox is
preassembled and requires only the
installation of the pitch slider and hub to
complete tail rotor assembly.
“I elected to use the Miniature Aircraft
metal tail rotor grips, which are very nice
and eliminate some of the associated free
play of the plastic parts. I found that I could
use an old 10mm main shaft to push the first
thrust bearing race into position easily and
without the chance of damaging the bearing.
“When bolted up correctly, they give
excellent performance and remain very tight
and slop free for extended periods, which is
also a plus for an FAI model. I am currently
using the new Youngblood Radix 105mm
tail rotor blades that are very stiff and
torsionally rigid.
“I find I can run lower tail rotor
deflection and still get the necessary spin
rates to do a clean 540° stall turn with a nice
precise stop at the end. Balance and CG of
the tail rotor blades was very good right out
of the package and required no additional
balancing. I have used several other types of
tail rotor blades also and most work fine.
Make sure the weight and balance are
correct and it will work.”
Sorry; I know I’m leaving you hanging,
but that’s all the space I’m allowed to use
right now. That machine sounds hot,
doesn’t it? Come back next month to see
how the Stratus FAI finished up and
Edition: Model Aviation - 2006/07
Page Numbers: 117,118,120,122
A guest helicopter review by Gordie Meade
[[email protected]]
Radio Control Helicopters Ray Stacy
ONE OF THE things I love about this
hobby is the variety. From electric to gas
power, there are many models available.
One of my goals for this column is to share
as much information as possible about as
many different helicopters as possible.
There is no way I can fly every machine,
so I rely on friends I have made throughout
the years to share their knowledge with us.
Gordie Meade is one of those people. He is
a longtime FAI F3C pilot, but, more
important, he is a straight shooter with an
honest opinion.
Gordie contacted me a few months ago
and said he would like to review the X-Cell
Stratus. I am impressed with his work; he
gave me such a detailed report that I need to
present it in two parts. Following is the first
portion; I think you will enjoy it.
“A few months back I decided I needed
a new model for the upcoming FAI contest
season. For 2006, the FAI F3C schedules
have been revised and the new schedules
require a slightly different style of model.
“The model needs a faster roll rate than
we have chosen to run in the past, there are
some outside pushes and inverted work, and hovering has been deemphasized,
so a lighter model seems to be a step toward the
‘solution.’
“For the past six or seven years I have flown the XL Pro, starting
with the early XL Pro I and ending with the last, the XL Pro IIK-T. I
loved the way my Pros hovered and flew and had a great deal of
success with them, but they had pretty much reached the end of their
development, because there just wasn’t much left that could be done
to improve the model any further.
“It weighed 11.5 pounds ready to fly, less fuel, and had a very
complex though efficient control system that was pretty much
interaction free but required regular routine maintenance to keep
accurate and slop free.
“I have flown all the Miniature Aircraft eCCPM Fury series,
having owned at one time or another a Fury Expert, several Fury
X-Cell Stratus kit contents with E-documentation loaded on the laptop. If you prefer a
hard-copy manual, Miniature Aircraft will send it to you.
New for the Stratus is this FAI head assembly.
The main shaft is supported by four bearings! Miniature Aircraft is
believed to be the only manufacturer to do this.
Note the Gear Ratio Adapter Plates in the starting-block area. A
plate for each gear ratio helps make alignment and mesh
adjustment easy.
July 2006 117
I got in touch with Miniature Aircraft
and ordered a Stratus conversion for my
Tempest FAI. Since the change in the
model was basically just a frame change, I
had the Stratus conversion ready to fly in a
comparatively short time.
“The model, ready to fly with the
Tempest FAI rotor head, the open tail-rotor
gearbox, 45-gram flybar paddles, YS .91
with Hatori SB16FH muffler, and 205-gram
symmetrical 720mm blades, weighed in at
10 pounds, 2 ounces—a stunning loss of a
pound and a half off my Nats FAI XL Pro
IIK-T. And as a bonus, the tank is rear
mounted on the Stratus versus front
mounted on the Fury and Tempest for a
more consistent center of gravity as the fuel
burns off.
“Most of the seriously competitive fliers
I know will tell you that in order to be ready
to seriously compete in FAI F3C, you need
to have two identical models ready to fly so
that if you run into a minor problem and
need to go to your back-up model, it’s very similar in performance
to your primary model. It also means you can split practice time
among two or three models and not put so much wear on a single
model, so it will last much longer before needing a rebuild.
“Since I had already decided to go with the Stratus for the 2006
season, I needed a second model. I placed a call to the Stratus
designer, Tim Schoonard, at Miniature Aircraft USA in Sorrento,
Florida, discussed my specific needs, and placed my order for a full
Stratus FAI kit. The Stratus kit comes in four varieties based on the
style of flying you want and the engine you opt to use.
“For the 3-D flier, the Stratus 3D kit for use with the O.S. .91
comes with an 8:18 gear ratio or for the YS .91 comes with an 8:45
gear ratio. For F3C, the Stratus FAI using the O.S. .91 comes with a
7:75 gear ratio and for the YS .91 comes with the 7:91 gear ratio.
“I have used the YS .91 with the 7:91 gear ratio in my
competition XL Pro IIs for several years and found the combination
to be smooth and fuel efficient in hover and to have excellent
straight-line speed in forward flight.
“From that experience, I selected the #1026-4 FAI Stratus with
the 7:91 gear ratio for the YS .91 and a short time later the ‘Little
Brown Helicopter Truck’ pulled up in front of the house and the
driver brought me a great big box. Upon opening the big shipping
box, I found inside a nicely packed kit box.
“The kit box is factory sealed, so the buyer can tell if the kit has
been opened, and each kit has its own unique serial number. If you
register the model with Miniature Aircraft, you will be kept
informed of updates and new information about the model as it
becomes available.
“I found the contents to be well protected and all machined and
plastic parts to be shrink-wrapped in plastic. The fiberglass canopyExtremes, and a Tempest FAI. When the Stratus conversions
became available, I was thinking about converting my Tempest FAI
to Stratus FAI to try the new frame configuration. Nearly at the
same time the Futaba 14MZ radio system became available and the
combination of the two, in my mind, made eCCPM workable for
F3C.
“My Fury Expert has flown with YS .61s, YS .80s, and now has
a YS .91 installed. I always loved the power of the control system
and the simplicity of the model, but it always had a little control
interaction at extremes of throw and for FAI that is really a major
problem.
“In my 9Z, I had several program mixes in place to fix the
majority of the interactions but always found that the servos changed
slightly over time and it was constantly necessary to ‘tweak’ the
mixes to keep the model neutral. I was never actually sure whether
the little ‘funnies’ I was getting periodically in flight were the result
of control interaction in the model or just poor piloting.
“The Tempest FAI had improved control geometry but still had
the forward-mounted tank and a very tall profile. I had flown the
Tempest the previous year and liked it but did not consider it to be a
quantum leap forward, but just a necessary evolutionary step.
“The 14MZ, with its advanced eCCPM program, made the
Stratus and other eCCPM models very workable for F3C. After
watching the Stratus 3D performing some outrageous extreme 3-D, I
spoke to Eric Larson and a couple of other pilots who were flying
the new Stratus, and they were very pleased with their models,
which exhibited amazing agility and performance, more so than any
of their previous models.
“Eric told me his model with an O.S. .91 weighed right around
10 pounds and the model’s amazing performance was directly
is in a separate area of the box, protected from shifting contents andon the engine are now extended through a
carbon-fiber baseplate as the primary engine
mount. There are smaller stabilizer mounts
that bolt to the engine’s normal mounting
lugs, and the whole subassembly bolts to the
baseplate of the model and is adjustable for
engine to clutch alignment. The net result is
a very open, uncluttered engine area with
good access to all engine components and
needles.
“Since I am using the YS .91, I borrowed
an idea from F3C pilot Dennis Purduski and
drilled and tapped two holes for long ball
links into the lower main baseplate. Instead
of plugging and unplugging fuel lines every
flight, I use a T fitting in both the fuel and
pressure lines and use these ball links as
plugs.
“This makes for a very nice, neat fuel
system, and you can vent the fuel tank after
a flight by pulling the vent line easily off the
ball link using only one hand, which
prevents the engine from flooding between
flights, and it keeps the fuel system neatly
out of the way. It’s really easy to do while
the model is in construction and saves a lot
of effort when preparing for a contest flight.
“Also I use different color fuel line for
different applications. On all my models,
fuel line is green, pressure line is yellow, so
I never get confused and pull the wrong one
and spray myself with fuel while trying to
vent the tank.
“You will also notice that I use very
short landing gear skids. The kit comes with
the standard X-Cell Tuff Struts, which are
very good, but for several years I have been
using the standard white Tuff Struts with the
X-Cell 30 skids. They are the same outside
diameter and fit the struts perfectly but are
shorter and lighter in weight.
“Since an FAI model is required to land
in a 1-meter circle, the smaller footprint of
the shorter skids gives just a little more
margin for error. Plus I think they look nice,
smaller, and more compact. I cannot tell any
trim difference in forward flight
performance, but I like the profile of the
smaller skids when in hover.
“I spent quite a bit of time getting the
cooling fan balanced and aligned on the
engine. The Stratus FAI comes with the XCell
machined aluminum fan which comes
pretty well balanced, but I always put a GV-1is currently the same canopy the Tempest
uses. My kit still has the interim fuel tank,
which will eventually be replaced by a
custom molded tank.
“The assembly instructions come on a
CD as an Adobe PDF file and require the
use of Adobe reader, which is a free
download on the Internet. Since there is no
printed main manual, assembly requires a
little creative thinking.
“The construction manual is lengthy at
186 pages, plus there is a separate printed
manual for the Tempest FAI rotor head. You
can take the CD to a print/copy place like
Kinko’s and have a hard copy made if you
want to have it available for bench
reference. Since I have a laptop computer, I
can place the laptop on my building table
and look at the pictures, read the
instructions, and build at the same time.
“The manual is full of pictures and each
part has its own identification picture, and
then the model is shown in stages of
assembly. Adobe reader has a built-in
magnifier so you can blow the pictures up to
200% if you want to see details. Every bolt
is identified by its size and length and is
shown both separately and installed in the
assembly.
“As with all the Miniature Aircraft
models, the Stratus goes together in
subassemblies, the lower main frames, the
upper main frames, the head, the tail rotor,
and so on. Each subassembly comes in a
bag, and within the main bag are smaller
bags with identification labels, which are in
alphabetical order of their use. Start with
Bag 1A, 1B, etc., follow the assembly
instructions until you run out of bags, and
you have a finished model.
“The Stratus differs from most current
model designs in one major way: the way
the engine is mounted to the lower main
frames. Most models, including the other
Miniature Aircraft glow designs, have a
machined aluminum engine mount that bolts
to the main frames and the mounting lugs on
the engine. The Stratus uses the engine as an
integral part of the frame.
“The same bolts that hold the backplatemagnet in the fan even if I don’t plan on
using a governor since I may change my
mind and it’s a pain to install the magnet
later.
“When everything is new and clean,
installing the magnet is easy but does require
that you rebalance the fan. I have been using
the Top Flite magnetic prop balancer for
quite awhile to balance my fans and have
had a lot of success. It took me about 15
minutes of testing the fan, drilling a dimple
to remove weight from the heavy side,
retesting, redrilling, until the fan would stop
randomly and would stay in any position it
was placed.
“If you are planning on using an optical
sensor, I’d suggest painting the bottom of
the fan flat black except for a 1/2-inch strip
which is left natural aluminum color and
again rebalance the fan after painting by
drilling a dimple or two on the top of the fan
between the fins on the heavy side.
“After flying F3C for a lot of years now,
I always want my fans aligned on the
crankshaft of the motor with a runout of less
than .001 inch. I have over the years tried
about 40 methods of doing this and find
some ways are better than others, but none I
have ever tried is fool-proof.
“For the Stratus, I used a method I got
from Ben Minor that requires tapping the fan
with a plastic hammer while supporting the
back of the crankshaft with a large wooden
dowel to keep load off the bearings and
engine case and gradually tightening the fan.
“It’s pretty easy to do if there are two
people but a lot tougher when you are
working alone, and it took me about an hour
and a half to get the fan aligned within +/-
.0005 inch, which makes the total runout
less than .001 inch which should be good.
“The instructions say to put oil on the
collets and spread it around to keep the fan
from binding to the collets while tightening.
I found a Permatex product called Antiseize
Lubricant in a little squeeze tube at the local
auto parts store that works even better and
makes the fan more easily removable if you
need to pull it to do engine work or
something. It works great.
“If you ever get a fan balanced and on an
engine with a zero runout, the model
achieves a state of ‘creaminess’ in flight that
has to be felt to be appreciated. Creaminess
is a term I picked up from Wayne Mann to
describe a model that is mechanically really
good. The engine drones smoothly, the
mechanics are smooth and quiet, and the
model just sits in a hover and hums. It’s hard
to describe in words, but once you see and
hear it, there is no doubt in your mind when
a model is doing it.
“If you elect to use one of the new O.S.
.91 SZs, it has a slightly different dimension
than either the YS .91 or the O.S. .91 CSpec,
and it does require a different collet
set, mounting screws, and baseplate.
Miniature has those parts in stock and can
supply them to you.
“The next assembly is the upper main
frames, and Miniature has come up with a
really great idea here. Everything is
assembled on one side of the upper frames,
which allows easy access to bearing blocks
for alignment. All three main shaft support
bearing blocks are loosely installed and the
main shaft inserted, and then each block is
tightened in place. The blocks are all aligned
with the main shaft and there is no binding.
“The main gear and retaining collars are
all installed and the tail rotor drive gear
mesh is set while everything is easily
AMA Academy of Model
Aeronautics
ARF Almost Ready to Fly
BEC Battery Eliminator Circuit
CAD computer-aided design
cc cubic centimeter
CD contest director or
compact disc
CG center of gravity
CL Control Line
cm centimeter
cu. in. cubic inch
DT dethermalizer
EPP (foam) expanded polypropylene
ESC Electronic Speed Control
FAI Fédération Aéronautique
Internationale
FCC Federal Communications
Commission
FF Free Flight
LCD Liquid Crystal Display
LE leading edge
LED light-emitting diode
Li-Poly Lithium Polymer
mA milliamperes
MA Model Aviation
mAh milliampere-hours
MHz megahertz
mm millimeter
Nats AMA Nationals
Ni-Cd Nickel Cadmium
NiMH Nickel Metal Hydride
RC Radio Control
rpm revolutions per minute
RTF Ready to Fly
SASE self-addressed, stamped
envelope
SIG Special Interest Group
TE trailing edge
ModelAviation’s Frequently Used
Abbreviations/Acronyms
accessible. The clutch is also installed and
aligned to the main gear while it is out in
the open and you are able to move it freely.
When everything is installed and
functioning smoothly, the other side is
bolted on and the upper frames are
completed.
“I do a couple of things differently from
the kit instructions. I use a tailboommounted
tail-rotor servo instead of the
frame-mounted servo that goes through a
bellcrank that comes with the kit. By
mounting the servo on the boom, I am able
to place my gyro sensor in the hole where
the tail rotor servo is supposed to be and get
the sensor farther away from the engine and
start shaft assembly with its inherent
vibration. I find I get a little better gyro
performance by doing that. Miniature has a
conversion to do it already made up: part
#126-85.
“The Stratus FAI comes with the new
open tail rotor gearbox which has the 4.7:1
tail rotor gear ratio, that gives you plenty of
authority when used in conjunction with the
105mm tail rotor blades. The gearbox is
preassembled and requires only the
installation of the pitch slider and hub to
complete tail rotor assembly.
“I elected to use the Miniature Aircraft
metal tail rotor grips, which are very nice
and eliminate some of the associated free
play of the plastic parts. I found that I could
use an old 10mm main shaft to push the first
thrust bearing race into position easily and
without the chance of damaging the bearing.
“When bolted up correctly, they give
excellent performance and remain very tight
and slop free for extended periods, which is
also a plus for an FAI model. I am currently
using the new Youngblood Radix 105mm
tail rotor blades that are very stiff and
torsionally rigid.
“I find I can run lower tail rotor
deflection and still get the necessary spin
rates to do a clean 540° stall turn with a nice
precise stop at the end. Balance and CG of
the tail rotor blades was very good right out
of the package and required no additional
balancing. I have used several other types of
tail rotor blades also and most work fine.
Make sure the weight and balance are
correct and it will work.”
Sorry; I know I’m leaving you hanging,
but that’s all the space I’m allowed to use
right now. That machine sounds hot,
doesn’t it? Come back next month to see
how the Stratus FAI finished up and
Edition: Model Aviation - 2006/07
Page Numbers: 117,118,120,122
A guest helicopter review by Gordie Meade
[[email protected]]
Radio Control Helicopters Ray Stacy
ONE OF THE things I love about this
hobby is the variety. From electric to gas
power, there are many models available.
One of my goals for this column is to share
as much information as possible about as
many different helicopters as possible.
There is no way I can fly every machine,
so I rely on friends I have made throughout
the years to share their knowledge with us.
Gordie Meade is one of those people. He is
a longtime FAI F3C pilot, but, more
important, he is a straight shooter with an
honest opinion.
Gordie contacted me a few months ago
and said he would like to review the X-Cell
Stratus. I am impressed with his work; he
gave me such a detailed report that I need to
present it in two parts. Following is the first
portion; I think you will enjoy it.
“A few months back I decided I needed
a new model for the upcoming FAI contest
season. For 2006, the FAI F3C schedules
have been revised and the new schedules
require a slightly different style of model.
“The model needs a faster roll rate than
we have chosen to run in the past, there are
some outside pushes and inverted work, and hovering has been deemphasized,
so a lighter model seems to be a step toward the
‘solution.’
“For the past six or seven years I have flown the XL Pro, starting
with the early XL Pro I and ending with the last, the XL Pro IIK-T. I
loved the way my Pros hovered and flew and had a great deal of
success with them, but they had pretty much reached the end of their
development, because there just wasn’t much left that could be done
to improve the model any further.
“It weighed 11.5 pounds ready to fly, less fuel, and had a very
complex though efficient control system that was pretty much
interaction free but required regular routine maintenance to keep
accurate and slop free.
“I have flown all the Miniature Aircraft eCCPM Fury series,
having owned at one time or another a Fury Expert, several Fury
X-Cell Stratus kit contents with E-documentation loaded on the laptop. If you prefer a
hard-copy manual, Miniature Aircraft will send it to you.
New for the Stratus is this FAI head assembly.
The main shaft is supported by four bearings! Miniature Aircraft is
believed to be the only manufacturer to do this.
Note the Gear Ratio Adapter Plates in the starting-block area. A
plate for each gear ratio helps make alignment and mesh
adjustment easy.
July 2006 117
I got in touch with Miniature Aircraft
and ordered a Stratus conversion for my
Tempest FAI. Since the change in the
model was basically just a frame change, I
had the Stratus conversion ready to fly in a
comparatively short time.
“The model, ready to fly with the
Tempest FAI rotor head, the open tail-rotor
gearbox, 45-gram flybar paddles, YS .91
with Hatori SB16FH muffler, and 205-gram
symmetrical 720mm blades, weighed in at
10 pounds, 2 ounces—a stunning loss of a
pound and a half off my Nats FAI XL Pro
IIK-T. And as a bonus, the tank is rear
mounted on the Stratus versus front
mounted on the Fury and Tempest for a
more consistent center of gravity as the fuel
burns off.
“Most of the seriously competitive fliers
I know will tell you that in order to be ready
to seriously compete in FAI F3C, you need
to have two identical models ready to fly so
that if you run into a minor problem and
need to go to your back-up model, it’s very similar in performance
to your primary model. It also means you can split practice time
among two or three models and not put so much wear on a single
model, so it will last much longer before needing a rebuild.
“Since I had already decided to go with the Stratus for the 2006
season, I needed a second model. I placed a call to the Stratus
designer, Tim Schoonard, at Miniature Aircraft USA in Sorrento,
Florida, discussed my specific needs, and placed my order for a full
Stratus FAI kit. The Stratus kit comes in four varieties based on the
style of flying you want and the engine you opt to use.
“For the 3-D flier, the Stratus 3D kit for use with the O.S. .91
comes with an 8:18 gear ratio or for the YS .91 comes with an 8:45
gear ratio. For F3C, the Stratus FAI using the O.S. .91 comes with a
7:75 gear ratio and for the YS .91 comes with the 7:91 gear ratio.
“I have used the YS .91 with the 7:91 gear ratio in my
competition XL Pro IIs for several years and found the combination
to be smooth and fuel efficient in hover and to have excellent
straight-line speed in forward flight.
“From that experience, I selected the #1026-4 FAI Stratus with
the 7:91 gear ratio for the YS .91 and a short time later the ‘Little
Brown Helicopter Truck’ pulled up in front of the house and the
driver brought me a great big box. Upon opening the big shipping
box, I found inside a nicely packed kit box.
“The kit box is factory sealed, so the buyer can tell if the kit has
been opened, and each kit has its own unique serial number. If you
register the model with Miniature Aircraft, you will be kept
informed of updates and new information about the model as it
becomes available.
“I found the contents to be well protected and all machined and
plastic parts to be shrink-wrapped in plastic. The fiberglass canopyExtremes, and a Tempest FAI. When the Stratus conversions
became available, I was thinking about converting my Tempest FAI
to Stratus FAI to try the new frame configuration. Nearly at the
same time the Futaba 14MZ radio system became available and the
combination of the two, in my mind, made eCCPM workable for
F3C.
“My Fury Expert has flown with YS .61s, YS .80s, and now has
a YS .91 installed. I always loved the power of the control system
and the simplicity of the model, but it always had a little control
interaction at extremes of throw and for FAI that is really a major
problem.
“In my 9Z, I had several program mixes in place to fix the
majority of the interactions but always found that the servos changed
slightly over time and it was constantly necessary to ‘tweak’ the
mixes to keep the model neutral. I was never actually sure whether
the little ‘funnies’ I was getting periodically in flight were the result
of control interaction in the model or just poor piloting.
“The Tempest FAI had improved control geometry but still had
the forward-mounted tank and a very tall profile. I had flown the
Tempest the previous year and liked it but did not consider it to be a
quantum leap forward, but just a necessary evolutionary step.
“The 14MZ, with its advanced eCCPM program, made the
Stratus and other eCCPM models very workable for F3C. After
watching the Stratus 3D performing some outrageous extreme 3-D, I
spoke to Eric Larson and a couple of other pilots who were flying
the new Stratus, and they were very pleased with their models,
which exhibited amazing agility and performance, more so than any
of their previous models.
“Eric told me his model with an O.S. .91 weighed right around
10 pounds and the model’s amazing performance was directly
is in a separate area of the box, protected from shifting contents andon the engine are now extended through a
carbon-fiber baseplate as the primary engine
mount. There are smaller stabilizer mounts
that bolt to the engine’s normal mounting
lugs, and the whole subassembly bolts to the
baseplate of the model and is adjustable for
engine to clutch alignment. The net result is
a very open, uncluttered engine area with
good access to all engine components and
needles.
“Since I am using the YS .91, I borrowed
an idea from F3C pilot Dennis Purduski and
drilled and tapped two holes for long ball
links into the lower main baseplate. Instead
of plugging and unplugging fuel lines every
flight, I use a T fitting in both the fuel and
pressure lines and use these ball links as
plugs.
“This makes for a very nice, neat fuel
system, and you can vent the fuel tank after
a flight by pulling the vent line easily off the
ball link using only one hand, which
prevents the engine from flooding between
flights, and it keeps the fuel system neatly
out of the way. It’s really easy to do while
the model is in construction and saves a lot
of effort when preparing for a contest flight.
“Also I use different color fuel line for
different applications. On all my models,
fuel line is green, pressure line is yellow, so
I never get confused and pull the wrong one
and spray myself with fuel while trying to
vent the tank.
“You will also notice that I use very
short landing gear skids. The kit comes with
the standard X-Cell Tuff Struts, which are
very good, but for several years I have been
using the standard white Tuff Struts with the
X-Cell 30 skids. They are the same outside
diameter and fit the struts perfectly but are
shorter and lighter in weight.
“Since an FAI model is required to land
in a 1-meter circle, the smaller footprint of
the shorter skids gives just a little more
margin for error. Plus I think they look nice,
smaller, and more compact. I cannot tell any
trim difference in forward flight
performance, but I like the profile of the
smaller skids when in hover.
“I spent quite a bit of time getting the
cooling fan balanced and aligned on the
engine. The Stratus FAI comes with the XCell
machined aluminum fan which comes
pretty well balanced, but I always put a GV-1is currently the same canopy the Tempest
uses. My kit still has the interim fuel tank,
which will eventually be replaced by a
custom molded tank.
“The assembly instructions come on a
CD as an Adobe PDF file and require the
use of Adobe reader, which is a free
download on the Internet. Since there is no
printed main manual, assembly requires a
little creative thinking.
“The construction manual is lengthy at
186 pages, plus there is a separate printed
manual for the Tempest FAI rotor head. You
can take the CD to a print/copy place like
Kinko’s and have a hard copy made if you
want to have it available for bench
reference. Since I have a laptop computer, I
can place the laptop on my building table
and look at the pictures, read the
instructions, and build at the same time.
“The manual is full of pictures and each
part has its own identification picture, and
then the model is shown in stages of
assembly. Adobe reader has a built-in
magnifier so you can blow the pictures up to
200% if you want to see details. Every bolt
is identified by its size and length and is
shown both separately and installed in the
assembly.
“As with all the Miniature Aircraft
models, the Stratus goes together in
subassemblies, the lower main frames, the
upper main frames, the head, the tail rotor,
and so on. Each subassembly comes in a
bag, and within the main bag are smaller
bags with identification labels, which are in
alphabetical order of their use. Start with
Bag 1A, 1B, etc., follow the assembly
instructions until you run out of bags, and
you have a finished model.
“The Stratus differs from most current
model designs in one major way: the way
the engine is mounted to the lower main
frames. Most models, including the other
Miniature Aircraft glow designs, have a
machined aluminum engine mount that bolts
to the main frames and the mounting lugs on
the engine. The Stratus uses the engine as an
integral part of the frame.
“The same bolts that hold the backplatemagnet in the fan even if I don’t plan on
using a governor since I may change my
mind and it’s a pain to install the magnet
later.
“When everything is new and clean,
installing the magnet is easy but does require
that you rebalance the fan. I have been using
the Top Flite magnetic prop balancer for
quite awhile to balance my fans and have
had a lot of success. It took me about 15
minutes of testing the fan, drilling a dimple
to remove weight from the heavy side,
retesting, redrilling, until the fan would stop
randomly and would stay in any position it
was placed.
“If you are planning on using an optical
sensor, I’d suggest painting the bottom of
the fan flat black except for a 1/2-inch strip
which is left natural aluminum color and
again rebalance the fan after painting by
drilling a dimple or two on the top of the fan
between the fins on the heavy side.
“After flying F3C for a lot of years now,
I always want my fans aligned on the
crankshaft of the motor with a runout of less
than .001 inch. I have over the years tried
about 40 methods of doing this and find
some ways are better than others, but none I
have ever tried is fool-proof.
“For the Stratus, I used a method I got
from Ben Minor that requires tapping the fan
with a plastic hammer while supporting the
back of the crankshaft with a large wooden
dowel to keep load off the bearings and
engine case and gradually tightening the fan.
“It’s pretty easy to do if there are two
people but a lot tougher when you are
working alone, and it took me about an hour
and a half to get the fan aligned within +/-
.0005 inch, which makes the total runout
less than .001 inch which should be good.
“The instructions say to put oil on the
collets and spread it around to keep the fan
from binding to the collets while tightening.
I found a Permatex product called Antiseize
Lubricant in a little squeeze tube at the local
auto parts store that works even better and
makes the fan more easily removable if you
need to pull it to do engine work or
something. It works great.
“If you ever get a fan balanced and on an
engine with a zero runout, the model
achieves a state of ‘creaminess’ in flight that
has to be felt to be appreciated. Creaminess
is a term I picked up from Wayne Mann to
describe a model that is mechanically really
good. The engine drones smoothly, the
mechanics are smooth and quiet, and the
model just sits in a hover and hums. It’s hard
to describe in words, but once you see and
hear it, there is no doubt in your mind when
a model is doing it.
“If you elect to use one of the new O.S.
.91 SZs, it has a slightly different dimension
than either the YS .91 or the O.S. .91 CSpec,
and it does require a different collet
set, mounting screws, and baseplate.
Miniature has those parts in stock and can
supply them to you.
“The next assembly is the upper main
frames, and Miniature has come up with a
really great idea here. Everything is
assembled on one side of the upper frames,
which allows easy access to bearing blocks
for alignment. All three main shaft support
bearing blocks are loosely installed and the
main shaft inserted, and then each block is
tightened in place. The blocks are all aligned
with the main shaft and there is no binding.
“The main gear and retaining collars are
all installed and the tail rotor drive gear
mesh is set while everything is easily
AMA Academy of Model
Aeronautics
ARF Almost Ready to Fly
BEC Battery Eliminator Circuit
CAD computer-aided design
cc cubic centimeter
CD contest director or
compact disc
CG center of gravity
CL Control Line
cm centimeter
cu. in. cubic inch
DT dethermalizer
EPP (foam) expanded polypropylene
ESC Electronic Speed Control
FAI Fédération Aéronautique
Internationale
FCC Federal Communications
Commission
FF Free Flight
LCD Liquid Crystal Display
LE leading edge
LED light-emitting diode
Li-Poly Lithium Polymer
mA milliamperes
MA Model Aviation
mAh milliampere-hours
MHz megahertz
mm millimeter
Nats AMA Nationals
Ni-Cd Nickel Cadmium
NiMH Nickel Metal Hydride
RC Radio Control
rpm revolutions per minute
RTF Ready to Fly
SASE self-addressed, stamped
envelope
SIG Special Interest Group
TE trailing edge
ModelAviation’s Frequently Used
Abbreviations/Acronyms
accessible. The clutch is also installed and
aligned to the main gear while it is out in
the open and you are able to move it freely.
When everything is installed and
functioning smoothly, the other side is
bolted on and the upper frames are
completed.
“I do a couple of things differently from
the kit instructions. I use a tailboommounted
tail-rotor servo instead of the
frame-mounted servo that goes through a
bellcrank that comes with the kit. By
mounting the servo on the boom, I am able
to place my gyro sensor in the hole where
the tail rotor servo is supposed to be and get
the sensor farther away from the engine and
start shaft assembly with its inherent
vibration. I find I get a little better gyro
performance by doing that. Miniature has a
conversion to do it already made up: part
#126-85.
“The Stratus FAI comes with the new
open tail rotor gearbox which has the 4.7:1
tail rotor gear ratio, that gives you plenty of
authority when used in conjunction with the
105mm tail rotor blades. The gearbox is
preassembled and requires only the
installation of the pitch slider and hub to
complete tail rotor assembly.
“I elected to use the Miniature Aircraft
metal tail rotor grips, which are very nice
and eliminate some of the associated free
play of the plastic parts. I found that I could
use an old 10mm main shaft to push the first
thrust bearing race into position easily and
without the chance of damaging the bearing.
“When bolted up correctly, they give
excellent performance and remain very tight
and slop free for extended periods, which is
also a plus for an FAI model. I am currently
using the new Youngblood Radix 105mm
tail rotor blades that are very stiff and
torsionally rigid.
“I find I can run lower tail rotor
deflection and still get the necessary spin
rates to do a clean 540° stall turn with a nice
precise stop at the end. Balance and CG of
the tail rotor blades was very good right out
of the package and required no additional
balancing. I have used several other types of
tail rotor blades also and most work fine.
Make sure the weight and balance are
correct and it will work.”
Sorry; I know I’m leaving you hanging,
but that’s all the space I’m allowed to use
right now. That machine sounds hot,
doesn’t it? Come back next month to see
how the Stratus FAI finished up and