88 MODEL AVIATION
I’VE SAID IT before, and I’ll say it again:
pushing the limits is what propels our hobby.
In this month’s column, I’ll let a fellow RCer
describe how he did just that.
You may have seen Jeremy Chinn’s name
in some of my other articles. We met through
the Profile Brotherhood (Pro Bros) and have
worked together at times to bring airplanes to
market.
In the following, he recalls his quest to
compete in the Nats RC Aerobatics (Pattern)
competition. What makes this story unique is
that he did so with a profile model, and he
designed and built the airplane. And if all that
wasn’t enough, the airplane is electric instead
of glow powered.
Read on to learn about Jeremy’s
experience, from start to finish, with his
Kudzu.
The Seed: Last fall I was analyzing my
flying, and I quickly realized that my biggest
weakness was precision. Through preparation
for the ETOC (Electric Tournament of Champions) and flying with
some of my local buddies, I realized that I enjoy flying Pattern. I spent
the whole winter flying indoor Pattern, as I have for the past three
years, and decided I wanted to fly it during the summer too.
Al Glenn, who is Quique Somenzini’s team manager, is one of
the people who pushed me to design a profile Pattern airplane.
Although the idea initially sounded crazy, it became more realistic
as we fleshed out the details.
I would design the aircraft to be an AMA- and FAI-legal 2-
meter Pattern model—no 3-D to it. It’s meant to draw only straight
lines. The new model’s outlines would borrow heavily from those
of the Vantage foamie I designed, but they wouldn’t be exactly the
same.
The plug-in wings and stabilizers would be constructed from
foam core, as would the fuselage, which would have 1/4-inchdiameter
tubes reinforcing it nose to tail. The fuselage would have
Born to Fly Jim T. Graham | [email protected]
Profiling and styling at the Nats
This is what great Pattern designs start out looking like: outlines. Jeremy Chinn
constructed his Kudzu as a simple profile aircraft.
This cut foam blossomed into a competitive Nats Pattern
machine. Hardwood motor rails tie into and support the wing
root structure.
The Kudzu takes shape. This is an exciting point in a scratch-built
airplane’s construction. It has that wide-body look.
01sig3.QXD 11/21/08 3:12 PM Page 88
January 2009 89
Left: All the hard work and thought
paid off. The Kudzu helped take Jeremy
to eighth place at the 2008 Nats: his
first Pattern competition.
Above: A.C. Glenn (R) assists Jeremy in
programming the radio and flighttesting
the Kudzu. The Nats was just
six days away.
Jeremy’s innovative model is considered even more of an
accomplishment because it employs modern electric power. Two
5S Li-Poly packs strap to either side.
stub wings and horizontals permanently attached, and house
incidence adjusters for total adjustability.
To avoid any glitches associated with the huge power in this
system, I would set up the airplane with a digital spread spectrum
radio from Day One. The servos would be Futaba mini digitals;
they’re light, strong, super-fast, and very good on centering. This
model would fly with a 10S Li-Poly battery system swinging a 20-
inch propeller.
Let the Building Begin: I began by installing the wing-tube sockets
and laying out the sheeting. After getting everything laid out, I had to
make the root ribs for the wings with the installed adjusters—not a
quick process. Then I had to do the rest of the core preparation,
including joining the panels, installing the servo boxes, and cutting
tubes into the wings for the servo extensions.
I laid out the sheeting and spread an extremely thin layer of
polyurethane glue over it. Then I put the core into the sheeting, sealed
all that in a vacuum bag, and kicked on my vacuum-bagging system.
It works like a charm and does an extremely good job of applying the
sheeting.
Power System: The motor will be a Dualsky 6350-16 (the model will
be built to take the 6360 motor in case more power is required), and a
Castle Creations Phoenix HV-85 ESC will be installed. I like the
Dualsky Great Transfer-series batteries and will pack two 5S1P 3700
Li-Poly packs to make a 10S system. An APC 19 x 12 propeller is
going to be mounted inside a Pete Model 3.5-inch carbon spinner.
The popular Spektrum AR7000 receiver will help guide the model,
and Futaba S9650 servos will go on all surfaces but the rudder, which
is going to have an S9152. Castle Creations’ CC BEC will provide
radio/servo power.
The AR7000 satellite receiver will go on the bottom of the
fuselage, as far back from the receiver as possible. The ESC will be
mounted as far forward as possible, to help balance the airplane.
All servos are going to be on 1/8 plywood rails mounted in balsa
reinforcements in the foam. The rudder servo should be mounted
amidships; it is currently in the tail and forcing me to put the batteries
farther forward than I had intended.
Ridiculous Headaches, Huge Enjoyment: I compared this project to
the ARF world in which most people fly. So far I’ve done the
following.
01sig3.QXD 11/21/08 3:14 PM Page 89
• Cut and milled the fuselage blank.
• Cut and prepped the rudder cores.
• Prepped the Hazzbro wing and stabilizer
cores.
• Hand cut all the balsa, plywood, and
hardwood parts.
• Built the vacuum-bag system for bagging
the cores.
• Built the wire-cutting setup for cutting the
rudder core.
• Laid up all the surfaces and fuselage.
• Covered the airframe.
• Made all the servo extensions.
This project has given me some ridiculous
headaches so far, but I’ve really enjoyed it. I
90 MODEL AVIATION
genuinely think I have gotten more out of this
airplane than ARF fliers get out of their
models.
There is undoubtedly a place for ARFs;
trying to get a flying fix in when you have a
job, kids, and a mortgage means that many
would not get to fly without ARFs. However,
the people who fly ARFs only are missing out
on the most rewarding part of the hobby.
This model has come out heavier than I
had hoped by 6-8 ounces, so I need to cut
some weight. I’ll start by trimming the
landing gear back. It’s too tall as well, so I’m
tempted to get another set and clip it shorter.
I’ll also drill the motor mount to save some
weight.
There are not many obvious opportunities
for me to drop weight on it right now.
It Flies! When I flew the Kudzu for the first
time, it took a click or so of aileron trim and a
click or so of rudder trim. Pitch input is
smooth. I need to dial down the elevator
throw and rudder throw; they also need
exponential.
Powerwise, I had more than enough for
the up-lines. The servos are more than strong
enough. Rolls are extremely axial, although I
had the rates too high.
I made two more flights the next morning.
Wow, what a wonderful airplane. It has a
slight pull to the canopy in knife-edge flight
that will be dialed out when the CG point is
moved back a hair more. The elevator trim
will be dialed out for that position as well.
The throws were backed off significantly
from what we used for the first flight. They
were backed off enough that I’ll likely move
the linkages out on the control horns and reset
the throws to the correct values.
The Kudzu is genuinely the most precise
profile model I’ve ever flown. It does seem to
settle down better with a little more speed, so
I may bump the propeller pitch up a bit and
choose a shorter size.
I flew the whole Intermediate Pattern
routine comfortably and threw in a few extra
maneuvers. I also flew some snaps with the
Kudzu that were perfect. It broke cleanly and
stopped the snap exactly where I wanted it to.
I must have gotten the wing pretty much
right.
Reporting From the Nats: Because of work
priorities, the Pilots’ Meeting was already
underway when I got to Muncie. We put the
model on the scale, and it weight 11 pounds,
7.6 ounces; this was a bad thing (the limit is
11 pounds). I went back to Pro Bro Dave
Sloan’s house, and we went to work.
Dave has a killer shop and he gave me
free reign to use whatever I needed—which
was almost every tool in there. To drop the
weight, we drilled holes in stuff, replaced all
the 4-40 hardware with 2-56 hardware, and
removed the wheel pants. You name it, we
lightened it.
How did flying go the first two days? The
Intermediate class had roughly 18
competitors. After the first two rounds (Day
One), I was in sixth place. I was definitely
happy with that.
Day Two (rounds 3 and 4) started with
high winds in our faces, which only got
worse. I’m not used to flying Pattern in high
winds, so I did not fare so well and dropped
to 11th overall. The next day was supposed to
be good as far as wind direction and speed, so
I was hoping to make up some ground.
The Kudzu performed very well. I got a
ton of offers to help develop it and many
requests to kit it. That made me feel good
about the design and its potential.
As the third day rolled to a close, the
airplane was still on the edge weightwise.
While Dave Sloan and I were trying to dial it
down even further, I called TnT Landing Gear
Products to find out what the company had in
stock that might help me reduce the weight.
TnT had some of the 40-size carbon gear
that I’ve used on 40-size profiles and offered
to ship it overnight to see if it would work.
The staff told me I could replace the gear if it
was not going to be up to the task. It turns out
that it was just right for the job.
The airplane did well on the new gear; it
got the stance and, more importantly, it got
the weight to the right range.
All that effort turned out to be worth it.
When I showed up for my round Thursday at
noon, the scales were there waiting for
everyone. Altogether, Dave and I pulled 11
ounces out of the Kudzu. It made weight, and
I got ready for the last two rounds.
Power had been a problem for me
throughout the Nats. Everyone said I needed
to carry more speed through my maneuvers.
I had the airplane at full throttle most of
the time, but I had run the Adjustable Travel
Volume (ATV) on the throttle back to 70% at
full bore to keep from burning up the motor.
For the last two rounds, I bumped the ATV
up to 90% and never looked back.
The motor, ESC, and batteries never got
hot. I can’t believe how much difference the
power made. In the end, I scored a 946
(which was good) on my final round and
moved up to eighth place overall—with only
six practice flights on the airplane before the
event.
All of the fliers who were in front of me
had been flying Pattern for many years, and
some had put in as many as 200 practice
flights in the two months before the event.
I’m proud of how I did and look forward to
flying again with some actual practice and
airplane development under my belt!
When my Nats adventure was finished, I
went back to work. Wow, was I tired—
literally about to slump over and fall asleep at
my desk. I drove nine hours after the final
round to get home. It was an interesting week
and probably one of the coolest aeromodeling
experiences I’ve ever had.
As Bob Sadler said regarding the Kudzu,
“Proof of concept, check!” The airplane
works. There is no doubt that it can be—and
was—competitive in AMA Pattern.
I will build a new fuselage sometime in
the next few months, with the hope of taking
8-12 ounces out of it. Fine-tuning the layout
will smooth out some of the model’s details.
Thanks to everyone who helped me out.
Edition: Model Aviation - 2009/01
Page Numbers: 88,89,90
Edition: Model Aviation - 2009/01
Page Numbers: 88,89,90
88 MODEL AVIATION
I’VE SAID IT before, and I’ll say it again:
pushing the limits is what propels our hobby.
In this month’s column, I’ll let a fellow RCer
describe how he did just that.
You may have seen Jeremy Chinn’s name
in some of my other articles. We met through
the Profile Brotherhood (Pro Bros) and have
worked together at times to bring airplanes to
market.
In the following, he recalls his quest to
compete in the Nats RC Aerobatics (Pattern)
competition. What makes this story unique is
that he did so with a profile model, and he
designed and built the airplane. And if all that
wasn’t enough, the airplane is electric instead
of glow powered.
Read on to learn about Jeremy’s
experience, from start to finish, with his
Kudzu.
The Seed: Last fall I was analyzing my
flying, and I quickly realized that my biggest
weakness was precision. Through preparation
for the ETOC (Electric Tournament of Champions) and flying with
some of my local buddies, I realized that I enjoy flying Pattern. I spent
the whole winter flying indoor Pattern, as I have for the past three
years, and decided I wanted to fly it during the summer too.
Al Glenn, who is Quique Somenzini’s team manager, is one of
the people who pushed me to design a profile Pattern airplane.
Although the idea initially sounded crazy, it became more realistic
as we fleshed out the details.
I would design the aircraft to be an AMA- and FAI-legal 2-
meter Pattern model—no 3-D to it. It’s meant to draw only straight
lines. The new model’s outlines would borrow heavily from those
of the Vantage foamie I designed, but they wouldn’t be exactly the
same.
The plug-in wings and stabilizers would be constructed from
foam core, as would the fuselage, which would have 1/4-inchdiameter
tubes reinforcing it nose to tail. The fuselage would have
Born to Fly Jim T. Graham | [email protected]
Profiling and styling at the Nats
This is what great Pattern designs start out looking like: outlines. Jeremy Chinn
constructed his Kudzu as a simple profile aircraft.
This cut foam blossomed into a competitive Nats Pattern
machine. Hardwood motor rails tie into and support the wing
root structure.
The Kudzu takes shape. This is an exciting point in a scratch-built
airplane’s construction. It has that wide-body look.
01sig3.QXD 11/21/08 3:12 PM Page 88
January 2009 89
Left: All the hard work and thought
paid off. The Kudzu helped take Jeremy
to eighth place at the 2008 Nats: his
first Pattern competition.
Above: A.C. Glenn (R) assists Jeremy in
programming the radio and flighttesting
the Kudzu. The Nats was just
six days away.
Jeremy’s innovative model is considered even more of an
accomplishment because it employs modern electric power. Two
5S Li-Poly packs strap to either side.
stub wings and horizontals permanently attached, and house
incidence adjusters for total adjustability.
To avoid any glitches associated with the huge power in this
system, I would set up the airplane with a digital spread spectrum
radio from Day One. The servos would be Futaba mini digitals;
they’re light, strong, super-fast, and very good on centering. This
model would fly with a 10S Li-Poly battery system swinging a 20-
inch propeller.
Let the Building Begin: I began by installing the wing-tube sockets
and laying out the sheeting. After getting everything laid out, I had to
make the root ribs for the wings with the installed adjusters—not a
quick process. Then I had to do the rest of the core preparation,
including joining the panels, installing the servo boxes, and cutting
tubes into the wings for the servo extensions.
I laid out the sheeting and spread an extremely thin layer of
polyurethane glue over it. Then I put the core into the sheeting, sealed
all that in a vacuum bag, and kicked on my vacuum-bagging system.
It works like a charm and does an extremely good job of applying the
sheeting.
Power System: The motor will be a Dualsky 6350-16 (the model will
be built to take the 6360 motor in case more power is required), and a
Castle Creations Phoenix HV-85 ESC will be installed. I like the
Dualsky Great Transfer-series batteries and will pack two 5S1P 3700
Li-Poly packs to make a 10S system. An APC 19 x 12 propeller is
going to be mounted inside a Pete Model 3.5-inch carbon spinner.
The popular Spektrum AR7000 receiver will help guide the model,
and Futaba S9650 servos will go on all surfaces but the rudder, which
is going to have an S9152. Castle Creations’ CC BEC will provide
radio/servo power.
The AR7000 satellite receiver will go on the bottom of the
fuselage, as far back from the receiver as possible. The ESC will be
mounted as far forward as possible, to help balance the airplane.
All servos are going to be on 1/8 plywood rails mounted in balsa
reinforcements in the foam. The rudder servo should be mounted
amidships; it is currently in the tail and forcing me to put the batteries
farther forward than I had intended.
Ridiculous Headaches, Huge Enjoyment: I compared this project to
the ARF world in which most people fly. So far I’ve done the
following.
01sig3.QXD 11/21/08 3:14 PM Page 89
• Cut and milled the fuselage blank.
• Cut and prepped the rudder cores.
• Prepped the Hazzbro wing and stabilizer
cores.
• Hand cut all the balsa, plywood, and
hardwood parts.
• Built the vacuum-bag system for bagging
the cores.
• Built the wire-cutting setup for cutting the
rudder core.
• Laid up all the surfaces and fuselage.
• Covered the airframe.
• Made all the servo extensions.
This project has given me some ridiculous
headaches so far, but I’ve really enjoyed it. I
90 MODEL AVIATION
genuinely think I have gotten more out of this
airplane than ARF fliers get out of their
models.
There is undoubtedly a place for ARFs;
trying to get a flying fix in when you have a
job, kids, and a mortgage means that many
would not get to fly without ARFs. However,
the people who fly ARFs only are missing out
on the most rewarding part of the hobby.
This model has come out heavier than I
had hoped by 6-8 ounces, so I need to cut
some weight. I’ll start by trimming the
landing gear back. It’s too tall as well, so I’m
tempted to get another set and clip it shorter.
I’ll also drill the motor mount to save some
weight.
There are not many obvious opportunities
for me to drop weight on it right now.
It Flies! When I flew the Kudzu for the first
time, it took a click or so of aileron trim and a
click or so of rudder trim. Pitch input is
smooth. I need to dial down the elevator
throw and rudder throw; they also need
exponential.
Powerwise, I had more than enough for
the up-lines. The servos are more than strong
enough. Rolls are extremely axial, although I
had the rates too high.
I made two more flights the next morning.
Wow, what a wonderful airplane. It has a
slight pull to the canopy in knife-edge flight
that will be dialed out when the CG point is
moved back a hair more. The elevator trim
will be dialed out for that position as well.
The throws were backed off significantly
from what we used for the first flight. They
were backed off enough that I’ll likely move
the linkages out on the control horns and reset
the throws to the correct values.
The Kudzu is genuinely the most precise
profile model I’ve ever flown. It does seem to
settle down better with a little more speed, so
I may bump the propeller pitch up a bit and
choose a shorter size.
I flew the whole Intermediate Pattern
routine comfortably and threw in a few extra
maneuvers. I also flew some snaps with the
Kudzu that were perfect. It broke cleanly and
stopped the snap exactly where I wanted it to.
I must have gotten the wing pretty much
right.
Reporting From the Nats: Because of work
priorities, the Pilots’ Meeting was already
underway when I got to Muncie. We put the
model on the scale, and it weight 11 pounds,
7.6 ounces; this was a bad thing (the limit is
11 pounds). I went back to Pro Bro Dave
Sloan’s house, and we went to work.
Dave has a killer shop and he gave me
free reign to use whatever I needed—which
was almost every tool in there. To drop the
weight, we drilled holes in stuff, replaced all
the 4-40 hardware with 2-56 hardware, and
removed the wheel pants. You name it, we
lightened it.
How did flying go the first two days? The
Intermediate class had roughly 18
competitors. After the first two rounds (Day
One), I was in sixth place. I was definitely
happy with that.
Day Two (rounds 3 and 4) started with
high winds in our faces, which only got
worse. I’m not used to flying Pattern in high
winds, so I did not fare so well and dropped
to 11th overall. The next day was supposed to
be good as far as wind direction and speed, so
I was hoping to make up some ground.
The Kudzu performed very well. I got a
ton of offers to help develop it and many
requests to kit it. That made me feel good
about the design and its potential.
As the third day rolled to a close, the
airplane was still on the edge weightwise.
While Dave Sloan and I were trying to dial it
down even further, I called TnT Landing Gear
Products to find out what the company had in
stock that might help me reduce the weight.
TnT had some of the 40-size carbon gear
that I’ve used on 40-size profiles and offered
to ship it overnight to see if it would work.
The staff told me I could replace the gear if it
was not going to be up to the task. It turns out
that it was just right for the job.
The airplane did well on the new gear; it
got the stance and, more importantly, it got
the weight to the right range.
All that effort turned out to be worth it.
When I showed up for my round Thursday at
noon, the scales were there waiting for
everyone. Altogether, Dave and I pulled 11
ounces out of the Kudzu. It made weight, and
I got ready for the last two rounds.
Power had been a problem for me
throughout the Nats. Everyone said I needed
to carry more speed through my maneuvers.
I had the airplane at full throttle most of
the time, but I had run the Adjustable Travel
Volume (ATV) on the throttle back to 70% at
full bore to keep from burning up the motor.
For the last two rounds, I bumped the ATV
up to 90% and never looked back.
The motor, ESC, and batteries never got
hot. I can’t believe how much difference the
power made. In the end, I scored a 946
(which was good) on my final round and
moved up to eighth place overall—with only
six practice flights on the airplane before the
event.
All of the fliers who were in front of me
had been flying Pattern for many years, and
some had put in as many as 200 practice
flights in the two months before the event.
I’m proud of how I did and look forward to
flying again with some actual practice and
airplane development under my belt!
When my Nats adventure was finished, I
went back to work. Wow, was I tired—
literally about to slump over and fall asleep at
my desk. I drove nine hours after the final
round to get home. It was an interesting week
and probably one of the coolest aeromodeling
experiences I’ve ever had.
As Bob Sadler said regarding the Kudzu,
“Proof of concept, check!” The airplane
works. There is no doubt that it can be—and
was—competitive in AMA Pattern.
I will build a new fuselage sometime in
the next few months, with the hope of taking
8-12 ounces out of it. Fine-tuning the layout
will smooth out some of the model’s details.
Thanks to everyone who helped me out.
Edition: Model Aviation - 2009/01
Page Numbers: 88,89,90
88 MODEL AVIATION
I’VE SAID IT before, and I’ll say it again:
pushing the limits is what propels our hobby.
In this month’s column, I’ll let a fellow RCer
describe how he did just that.
You may have seen Jeremy Chinn’s name
in some of my other articles. We met through
the Profile Brotherhood (Pro Bros) and have
worked together at times to bring airplanes to
market.
In the following, he recalls his quest to
compete in the Nats RC Aerobatics (Pattern)
competition. What makes this story unique is
that he did so with a profile model, and he
designed and built the airplane. And if all that
wasn’t enough, the airplane is electric instead
of glow powered.
Read on to learn about Jeremy’s
experience, from start to finish, with his
Kudzu.
The Seed: Last fall I was analyzing my
flying, and I quickly realized that my biggest
weakness was precision. Through preparation
for the ETOC (Electric Tournament of Champions) and flying with
some of my local buddies, I realized that I enjoy flying Pattern. I spent
the whole winter flying indoor Pattern, as I have for the past three
years, and decided I wanted to fly it during the summer too.
Al Glenn, who is Quique Somenzini’s team manager, is one of
the people who pushed me to design a profile Pattern airplane.
Although the idea initially sounded crazy, it became more realistic
as we fleshed out the details.
I would design the aircraft to be an AMA- and FAI-legal 2-
meter Pattern model—no 3-D to it. It’s meant to draw only straight
lines. The new model’s outlines would borrow heavily from those
of the Vantage foamie I designed, but they wouldn’t be exactly the
same.
The plug-in wings and stabilizers would be constructed from
foam core, as would the fuselage, which would have 1/4-inchdiameter
tubes reinforcing it nose to tail. The fuselage would have
Born to Fly Jim T. Graham | [email protected]
Profiling and styling at the Nats
This is what great Pattern designs start out looking like: outlines. Jeremy Chinn
constructed his Kudzu as a simple profile aircraft.
This cut foam blossomed into a competitive Nats Pattern
machine. Hardwood motor rails tie into and support the wing
root structure.
The Kudzu takes shape. This is an exciting point in a scratch-built
airplane’s construction. It has that wide-body look.
01sig3.QXD 11/21/08 3:12 PM Page 88
January 2009 89
Left: All the hard work and thought
paid off. The Kudzu helped take Jeremy
to eighth place at the 2008 Nats: his
first Pattern competition.
Above: A.C. Glenn (R) assists Jeremy in
programming the radio and flighttesting
the Kudzu. The Nats was just
six days away.
Jeremy’s innovative model is considered even more of an
accomplishment because it employs modern electric power. Two
5S Li-Poly packs strap to either side.
stub wings and horizontals permanently attached, and house
incidence adjusters for total adjustability.
To avoid any glitches associated with the huge power in this
system, I would set up the airplane with a digital spread spectrum
radio from Day One. The servos would be Futaba mini digitals;
they’re light, strong, super-fast, and very good on centering. This
model would fly with a 10S Li-Poly battery system swinging a 20-
inch propeller.
Let the Building Begin: I began by installing the wing-tube sockets
and laying out the sheeting. After getting everything laid out, I had to
make the root ribs for the wings with the installed adjusters—not a
quick process. Then I had to do the rest of the core preparation,
including joining the panels, installing the servo boxes, and cutting
tubes into the wings for the servo extensions.
I laid out the sheeting and spread an extremely thin layer of
polyurethane glue over it. Then I put the core into the sheeting, sealed
all that in a vacuum bag, and kicked on my vacuum-bagging system.
It works like a charm and does an extremely good job of applying the
sheeting.
Power System: The motor will be a Dualsky 6350-16 (the model will
be built to take the 6360 motor in case more power is required), and a
Castle Creations Phoenix HV-85 ESC will be installed. I like the
Dualsky Great Transfer-series batteries and will pack two 5S1P 3700
Li-Poly packs to make a 10S system. An APC 19 x 12 propeller is
going to be mounted inside a Pete Model 3.5-inch carbon spinner.
The popular Spektrum AR7000 receiver will help guide the model,
and Futaba S9650 servos will go on all surfaces but the rudder, which
is going to have an S9152. Castle Creations’ CC BEC will provide
radio/servo power.
The AR7000 satellite receiver will go on the bottom of the
fuselage, as far back from the receiver as possible. The ESC will be
mounted as far forward as possible, to help balance the airplane.
All servos are going to be on 1/8 plywood rails mounted in balsa
reinforcements in the foam. The rudder servo should be mounted
amidships; it is currently in the tail and forcing me to put the batteries
farther forward than I had intended.
Ridiculous Headaches, Huge Enjoyment: I compared this project to
the ARF world in which most people fly. So far I’ve done the
following.
01sig3.QXD 11/21/08 3:14 PM Page 89
• Cut and milled the fuselage blank.
• Cut and prepped the rudder cores.
• Prepped the Hazzbro wing and stabilizer
cores.
• Hand cut all the balsa, plywood, and
hardwood parts.
• Built the vacuum-bag system for bagging
the cores.
• Built the wire-cutting setup for cutting the
rudder core.
• Laid up all the surfaces and fuselage.
• Covered the airframe.
• Made all the servo extensions.
This project has given me some ridiculous
headaches so far, but I’ve really enjoyed it. I
90 MODEL AVIATION
genuinely think I have gotten more out of this
airplane than ARF fliers get out of their
models.
There is undoubtedly a place for ARFs;
trying to get a flying fix in when you have a
job, kids, and a mortgage means that many
would not get to fly without ARFs. However,
the people who fly ARFs only are missing out
on the most rewarding part of the hobby.
This model has come out heavier than I
had hoped by 6-8 ounces, so I need to cut
some weight. I’ll start by trimming the
landing gear back. It’s too tall as well, so I’m
tempted to get another set and clip it shorter.
I’ll also drill the motor mount to save some
weight.
There are not many obvious opportunities
for me to drop weight on it right now.
It Flies! When I flew the Kudzu for the first
time, it took a click or so of aileron trim and a
click or so of rudder trim. Pitch input is
smooth. I need to dial down the elevator
throw and rudder throw; they also need
exponential.
Powerwise, I had more than enough for
the up-lines. The servos are more than strong
enough. Rolls are extremely axial, although I
had the rates too high.
I made two more flights the next morning.
Wow, what a wonderful airplane. It has a
slight pull to the canopy in knife-edge flight
that will be dialed out when the CG point is
moved back a hair more. The elevator trim
will be dialed out for that position as well.
The throws were backed off significantly
from what we used for the first flight. They
were backed off enough that I’ll likely move
the linkages out on the control horns and reset
the throws to the correct values.
The Kudzu is genuinely the most precise
profile model I’ve ever flown. It does seem to
settle down better with a little more speed, so
I may bump the propeller pitch up a bit and
choose a shorter size.
I flew the whole Intermediate Pattern
routine comfortably and threw in a few extra
maneuvers. I also flew some snaps with the
Kudzu that were perfect. It broke cleanly and
stopped the snap exactly where I wanted it to.
I must have gotten the wing pretty much
right.
Reporting From the Nats: Because of work
priorities, the Pilots’ Meeting was already
underway when I got to Muncie. We put the
model on the scale, and it weight 11 pounds,
7.6 ounces; this was a bad thing (the limit is
11 pounds). I went back to Pro Bro Dave
Sloan’s house, and we went to work.
Dave has a killer shop and he gave me
free reign to use whatever I needed—which
was almost every tool in there. To drop the
weight, we drilled holes in stuff, replaced all
the 4-40 hardware with 2-56 hardware, and
removed the wheel pants. You name it, we
lightened it.
How did flying go the first two days? The
Intermediate class had roughly 18
competitors. After the first two rounds (Day
One), I was in sixth place. I was definitely
happy with that.
Day Two (rounds 3 and 4) started with
high winds in our faces, which only got
worse. I’m not used to flying Pattern in high
winds, so I did not fare so well and dropped
to 11th overall. The next day was supposed to
be good as far as wind direction and speed, so
I was hoping to make up some ground.
The Kudzu performed very well. I got a
ton of offers to help develop it and many
requests to kit it. That made me feel good
about the design and its potential.
As the third day rolled to a close, the
airplane was still on the edge weightwise.
While Dave Sloan and I were trying to dial it
down even further, I called TnT Landing Gear
Products to find out what the company had in
stock that might help me reduce the weight.
TnT had some of the 40-size carbon gear
that I’ve used on 40-size profiles and offered
to ship it overnight to see if it would work.
The staff told me I could replace the gear if it
was not going to be up to the task. It turns out
that it was just right for the job.
The airplane did well on the new gear; it
got the stance and, more importantly, it got
the weight to the right range.
All that effort turned out to be worth it.
When I showed up for my round Thursday at
noon, the scales were there waiting for
everyone. Altogether, Dave and I pulled 11
ounces out of the Kudzu. It made weight, and
I got ready for the last two rounds.
Power had been a problem for me
throughout the Nats. Everyone said I needed
to carry more speed through my maneuvers.
I had the airplane at full throttle most of
the time, but I had run the Adjustable Travel
Volume (ATV) on the throttle back to 70% at
full bore to keep from burning up the motor.
For the last two rounds, I bumped the ATV
up to 90% and never looked back.
The motor, ESC, and batteries never got
hot. I can’t believe how much difference the
power made. In the end, I scored a 946
(which was good) on my final round and
moved up to eighth place overall—with only
six practice flights on the airplane before the
event.
All of the fliers who were in front of me
had been flying Pattern for many years, and
some had put in as many as 200 practice
flights in the two months before the event.
I’m proud of how I did and look forward to
flying again with some actual practice and
airplane development under my belt!
When my Nats adventure was finished, I
went back to work. Wow, was I tired—
literally about to slump over and fall asleep at
my desk. I drove nine hours after the final
round to get home. It was an interesting week
and probably one of the coolest aeromodeling
experiences I’ve ever had.
As Bob Sadler said regarding the Kudzu,
“Proof of concept, check!” The airplane
works. There is no doubt that it can be—and
was—competitive in AMA Pattern.
I will build a new fuselage sometime in
the next few months, with the hope of taking
8-12 ounces out of it. Fine-tuning the layout
will smooth out some of the model’s details.
Thanks to everyone who helped me out.