“Covering: UltraCote. The front half of
the cowl is covered in Sig AeroKote ironed
on over the ABS cowl (worked very well
with low heat). I printed the decals on my
ink-jet printer using Micro-Mark water
slide decal paper. The decals were sealed
with Krylon Crystal Clear. The color
scheme is based on the full-scale ‘Furias’
Reno Racer.
“Building detail: The laser-cut kit went
together almost flawlessly. Wood quality
was excellent. I lightened all plywood
formers and wing ribs. I didn’t use any
other weight-saving techniques to bring my
e-powered Sea Fury
in 1/2-pound lighter
than my friend’s
wet-powered
example.
“I did create an
access hatch for the
power pack. There
is plenty of room
for up to a 9S3P
pack. I intentionally
moved the elevator
horn to the top so
that it would pull
for up-elevator, as I
anticipated some
high-‘G’ Reno-type
turns.
“Flying: Wow!
It was off the
ground at half
throttle. Two clicks
of up-elevator and
four of right aileron,
and it was flying
Walt Thyng describes his fabulous Direct Connections Sea Fury
February 2006 107
Electrics Greg Gimlick | [email protected]
With an all-up weight of 8.25 pounds, Walt Thyng’s gorgeous AXI 4130/20 motorpowered
Sea Fury is lighter than his friend’s 1.20-powered version.
Walt used off-the-shelf mailbox mounting brackets to mount the
AXI in the Sea Fury. It’s a simple and easy method.
BEFORE I GET going this month I want
to thank all who wrote and called during my
recent illness. What a joy to find out how
many modelers really care about one
another.
Rest assured I am on the mend and
getting better all the time. I’m back to flying
and building, so my wife figures I’ll live
now. Thank you again and I hope to see you
at many events this year.
Featured Model of the Month: Walt Thyng
has been building some incredible Electrics
for a long time, so it’s always great to see
something show up in my inbox from him.
Following is Walt’s description of his
Direct Connections Sea Fury, which spans
64 inches and has an area of 791 square
inches.
“The all-up weight is 8.25 pounds with
D&B mechanical retracts powered by a
Hitec retract servo.
“Radio: Transmitter and receiver are
Airtronics. The receiver battery is a fourcell
CP-1300 Sanyo Ni-Cd pack.
“Servos: I’m using two Hitec HS-81s
for the ailerons and Futaba standards for the
rudder and elevator.
“Pushrods: Dave Brown Products
fiberglass with 4-40 rods and clevises.
There are no flaps since the full-scale
version had them removed for weight and
streamlining.
“Power system: I’m using an AXI
4130/20 Outrunner motor, a Hacker Master
77 opto ESC, a 9S2P Thunder Power 2100
Li-Poly battery pack, and an APC-E 14 x 12
propeller. Static amp draw is 41.
straight and true. (I later added 3° of
downthrust.) This is a very stable and fast
flier.
“I had originally planned to go to a
10S3P pack and larger prop to get a 90+
mph airspeed, which would be close to onesixth
of the top speed obtained by the real
Furias. I don’t think I need to do that.
“Flight characteristic are typical of a
warbird. Rolls are fairly axial with careful
use of elevator. Loops can be any size you
want. The stall is a gentle straight-ahead
drop of the nose. Slow flight produces a
crawl with controls effective right up to the
stall. I haven’t gotten it to spin after eight
flights.
“This is one great-flying airplane that
handles better than my Top Flite P-47.”
Building Tip: I’m going to use a photo of
Walt’s motor mount for a tip because it’s
just so easy. The photo tells it all; it’s a
simple mailbox mounting kit available from
Also included in this column:
108 MODEL AVIATION
West Mountain Radio’s single-cell clamp allows testing of
individual cells. It’s shown testing a cell with the CBA II.
Canadian-made Merlin brushless motors. The labeled one is the
R2000 “Y”-wind motor, and the other is the R2001 “D” wind.
Thunder Tiger’s 3-D foam Christen Eagle is quick to build and good in quality.
most of the big home-improvement stores. Full adjustability and
light weight make it worth trying the next time you’re in a pinch for
a mount.
Cool Tool: I’ve written about using solderless power tubes for my
Ni-Cd and NiMH packs because I hate to solder and like to be able
to check on the condition of individual cells. The problem it creates
is how to attach a single cell to an analyzer such as West Mountain
Radio’s CBA II that I use all the time.
I’ve seen all sorts of elaborate homemade fixtures with which to
do this, but they all seemed like too much work and too
complicated. However, West Mountain Radio has made a single-cell
clamp, complete with connectors. Now all I have to do is stick the
cell in and start testing. This is a great tool!
New Brushless Motors: In the last column I teased you with a
mention of some new brushless motors that would soon be available
from Model Electronics Corporation (MEC). They are now
available.
Although I had hoped to have one in a model by now, all I’ve
managed to do is test them on the bench. So far they have stood up
well to my bench abuse, and I have every reason to believe that they
will perform well in the 1/4-scale Gee Bee R-2 I’m converting.
Okay, enough teasing; these are Merlin motors made in Canada,
and they come in two variations. The R2000 is a “Y”-wind motor
with 1,560 rpm/volts (KV), a resistance of 0.06 ohm, a no-load
current of 1.3 amps, and a maximum current of 50 amps. The R2001
is a “D”-wind motor with a KV of 2,400, a resistance of 0.02 ohm, a
no-load current of 2.5 amps, and a maximum current of 70 amps.
Each motor is rated at 1.2 kilowatts (with adequate cooling), and
the maximum rpm is limited to 50,000. Each motor has a 5mm shaft,
and the size is 34.8mm in diameter, 5,802mm in length, and 196
grams.
Although my testing is not as thorough as I’d like yet, I am
impressed with what I’ve seen and I’ve run the motors to well past
the rated 1.2 kilowatts. They are priced competitively, so give Pete a
call at MEC and check them out.
Motor-Naming Conundrum: There is no standard for naming
motors. It’s that plain and simple whether we like it or not.
I’ve gotten more E-mail messages and letters about this situation
throughout the years than anything else. People want to know why
there isn’t a standard or why the magazines haven’t made the
manufacturers do something about it (as if we could).
There are so many answers to that I won’t even attempt to sort
them out. Each manufacturer has its own reasons why it thinks its
method of naming motors is the best, and each has a good
argument for it.
The best way to find out about a motor
is to go to the manufacturer’s Web site or
one of its vendor sites and look at the
application charts most provide. Call and
ask the company if the motor you’re
considering is right for your application.
Make the personnel guide you to the right
motor if you’re confused so you don’t waste
your money. Most vendors are more than
happy to do that.
What I can do is give you some
common motor names and tell you what the
numbers mean.
• AstroFlight: Astro has been around for
longer than Bob Boucher probably wants to
think about, but his motors have been topnotch
since the beginning. Bob originally
named his engines to try to correlate to the
glow engines they would replace. If you
flew with a .25 engine, you would use an
Astro 25 motor. If you had a .40 engine, an
Astro 40 motor would do the trick, and so
on.
As things developed and motors
improved along with gearing, etc., this
system didn’t hold up; I’ve flown 25- and
40-size models with Astro 15G motors.
But AstroFlight has continued to use this
designation, and there’s something to be
said for consistency; everyone has come to
know the various sizes and capabilities of
the motors by their designations.
• Graupner: You are probably familiar
with the Speed 400, 550, 600, and 700
series of ferrite motors. These are named
by the diameter of the motors. That
doesn’t tell you much, but these motors
have been around for so long that
modelers have come to know what they’re
meant for.
The most common size is probably the
Speed 400, which comes in 4.8-, 6.0-, and
7.2-volt versions and even higher if you
dig deep enough. The motor is actually
38mm in diameter, but the numbers are
rounded up. When you hear someone
speak of a 380 motor, he or she is using
Mabuchi’s actual size.
The name will get you the size of the
motor, but you’ll have to search further for
the voltage rating, and other information.
Hobby Lobby’s Web site and catalog have
a good set of charts to show you the
constants for each motor in this class and
appropriate applications.
• Mega: These motors are designated by the
size of the armature and the number of
turns. Many companies have used similar
methods, but they use the size of the case
instead of the armature.
A Mega Acn 22/45/2 means the
armature (rotor) diameter is 22mm, the
length is 45mm, and this is a two-turn
motor. For comparison, this is
approximately the same physical size as a
Speed 600 motor, and the Mega 16/15/6 is
the size of a Speed 400 motor.
By indicating the winds, some clue is
given about how “hot” the motor is. You
need to consult the charts and check for
proper application unless someone gives
you a recommendation.
• Hacker: This company’s motors are
named using the length of the rotor and the
number of winds. If you see a B40 8XL,
you know the rotor is 40mm long, the
motor has eight turns, and the motor’s body
is extra long. Hacker uses S, L, and XL for
length; the longer the body, the more torque
the motor can produce.
Sometimes you’ll see one of these
power plants listed as B50 12XL+4.4:1.
That means the armature is 50mm in
diameter, and the motor has 12 turns in an
extra-long case attached to a planetary
gearbox geared 4.4:1.
• AXI: The diameter and length of the
armature along with the number of turns are
used to designate these motors’ sizes. When
you see a 2820/12, you know its rotor
diameter is 28mm, the length is 20mm, and
the number of turns is 12.
Although there is no standard for
naming motors, there is some consensus
among manufacturers that the numbers
should represent the size and number of
turns. They don’t make it apparent whether
they’re referring to case size, armature size,
or a bit of both, but the armature is close to
the case size, so it’s not all that significant.
(We’re not being engineers here.)
Some companies also list the KV at the
end of their designations. I’m still a
believer in the computer modeling
programs such as ElectriCalc and MotoCalc
to help select motors. Armed with the
motor constants, you can plug them into
these programs and get a general idea of
what they will do in your application. You
can also compare various winds side by
side in a printout to see how they affect
your outcome.
There are more motors on the market
today than I would have dreamed, so it can
be daunting to sort through them all. The
most important thing is to ask your vendor
if you have questions! If that company
can’t answer them, find one that can.
Microflight Info: This is a bit out of my
area of expertise, but I’ve gotten inquiriesnewsletter, edited by John Worth, that Air
Age used to publish. Air Age discontinued
the publication, but John is hard at work
doing an exceptional online subscription
version called RC Micro World.
The price is $12, and you can read this
publication online or download it in PDF
format from www.cloud9rc.com. It’s every
bit as good as it used to be (maybe even
better), and I encourage you to support John’s
efforts.
Microflight has come a long way and
adds another dimension to your electricpower
flying—especially if you live in the
colder sections of the country and have access
to some indoor facilities. Check it out!
Final Approach: We’re in the depths of
winter, so you may be busy building those
projects for spring. A photo shows a Thunder
Tiger Christen Eagle 3-D foamie I’ll be
finishing soon, so look for more about it in
the near future.
Send your pictures and info to me, and
shoot digital photos in high resolution for
publication. Also send in your building tips
and tricks; they are popular judging from the
reader mail I’m getting. MA
Sources:
AstroFlight Inc.
13311 Beach Ave.
Marina Del Rey CA 90292
(310) 821-6242
(310) 822-6637
[email protected]
www.astroflight.com
Model Electronics Corporation
11512-155 Ave. SE
Renton WA 98059
(866) 507-9956 (excluding Canada)
(425) 255-4269
Fax: (425) 255-1558
[email protected]
www.modelelectronicscorp.com
Hobby Lobby International, Inc. (for
Graupner, AXI products)
5614 Franklin Pike Cir.
Brentwood TN 37027
(615) 373-1444
Fax: (615) 377-6948
www.hobby-lobby.com
West Mountain Radio
18 Sheehan Ave.
Norwalk CT 06854
(203) 853-8080
Fax: (203) 299-0232
www.westmountainradio.com
Edition: Model Aviation - 2006/02
Page Numbers: 107,108,110,112
Edition: Model Aviation - 2006/02
Page Numbers: 107,108,110,112
“Covering: UltraCote. The front half of
the cowl is covered in Sig AeroKote ironed
on over the ABS cowl (worked very well
with low heat). I printed the decals on my
ink-jet printer using Micro-Mark water
slide decal paper. The decals were sealed
with Krylon Crystal Clear. The color
scheme is based on the full-scale ‘Furias’
Reno Racer.
“Building detail: The laser-cut kit went
together almost flawlessly. Wood quality
was excellent. I lightened all plywood
formers and wing ribs. I didn’t use any
other weight-saving techniques to bring my
e-powered Sea Fury
in 1/2-pound lighter
than my friend’s
wet-powered
example.
“I did create an
access hatch for the
power pack. There
is plenty of room
for up to a 9S3P
pack. I intentionally
moved the elevator
horn to the top so
that it would pull
for up-elevator, as I
anticipated some
high-‘G’ Reno-type
turns.
“Flying: Wow!
It was off the
ground at half
throttle. Two clicks
of up-elevator and
four of right aileron,
and it was flying
Walt Thyng describes his fabulous Direct Connections Sea Fury
February 2006 107
Electrics Greg Gimlick | [email protected]
With an all-up weight of 8.25 pounds, Walt Thyng’s gorgeous AXI 4130/20 motorpowered
Sea Fury is lighter than his friend’s 1.20-powered version.
Walt used off-the-shelf mailbox mounting brackets to mount the
AXI in the Sea Fury. It’s a simple and easy method.
BEFORE I GET going this month I want
to thank all who wrote and called during my
recent illness. What a joy to find out how
many modelers really care about one
another.
Rest assured I am on the mend and
getting better all the time. I’m back to flying
and building, so my wife figures I’ll live
now. Thank you again and I hope to see you
at many events this year.
Featured Model of the Month: Walt Thyng
has been building some incredible Electrics
for a long time, so it’s always great to see
something show up in my inbox from him.
Following is Walt’s description of his
Direct Connections Sea Fury, which spans
64 inches and has an area of 791 square
inches.
“The all-up weight is 8.25 pounds with
D&B mechanical retracts powered by a
Hitec retract servo.
“Radio: Transmitter and receiver are
Airtronics. The receiver battery is a fourcell
CP-1300 Sanyo Ni-Cd pack.
“Servos: I’m using two Hitec HS-81s
for the ailerons and Futaba standards for the
rudder and elevator.
“Pushrods: Dave Brown Products
fiberglass with 4-40 rods and clevises.
There are no flaps since the full-scale
version had them removed for weight and
streamlining.
“Power system: I’m using an AXI
4130/20 Outrunner motor, a Hacker Master
77 opto ESC, a 9S2P Thunder Power 2100
Li-Poly battery pack, and an APC-E 14 x 12
propeller. Static amp draw is 41.
straight and true. (I later added 3° of
downthrust.) This is a very stable and fast
flier.
“I had originally planned to go to a
10S3P pack and larger prop to get a 90+
mph airspeed, which would be close to onesixth
of the top speed obtained by the real
Furias. I don’t think I need to do that.
“Flight characteristic are typical of a
warbird. Rolls are fairly axial with careful
use of elevator. Loops can be any size you
want. The stall is a gentle straight-ahead
drop of the nose. Slow flight produces a
crawl with controls effective right up to the
stall. I haven’t gotten it to spin after eight
flights.
“This is one great-flying airplane that
handles better than my Top Flite P-47.”
Building Tip: I’m going to use a photo of
Walt’s motor mount for a tip because it’s
just so easy. The photo tells it all; it’s a
simple mailbox mounting kit available from
Also included in this column:
108 MODEL AVIATION
West Mountain Radio’s single-cell clamp allows testing of
individual cells. It’s shown testing a cell with the CBA II.
Canadian-made Merlin brushless motors. The labeled one is the
R2000 “Y”-wind motor, and the other is the R2001 “D” wind.
Thunder Tiger’s 3-D foam Christen Eagle is quick to build and good in quality.
most of the big home-improvement stores. Full adjustability and
light weight make it worth trying the next time you’re in a pinch for
a mount.
Cool Tool: I’ve written about using solderless power tubes for my
Ni-Cd and NiMH packs because I hate to solder and like to be able
to check on the condition of individual cells. The problem it creates
is how to attach a single cell to an analyzer such as West Mountain
Radio’s CBA II that I use all the time.
I’ve seen all sorts of elaborate homemade fixtures with which to
do this, but they all seemed like too much work and too
complicated. However, West Mountain Radio has made a single-cell
clamp, complete with connectors. Now all I have to do is stick the
cell in and start testing. This is a great tool!
New Brushless Motors: In the last column I teased you with a
mention of some new brushless motors that would soon be available
from Model Electronics Corporation (MEC). They are now
available.
Although I had hoped to have one in a model by now, all I’ve
managed to do is test them on the bench. So far they have stood up
well to my bench abuse, and I have every reason to believe that they
will perform well in the 1/4-scale Gee Bee R-2 I’m converting.
Okay, enough teasing; these are Merlin motors made in Canada,
and they come in two variations. The R2000 is a “Y”-wind motor
with 1,560 rpm/volts (KV), a resistance of 0.06 ohm, a no-load
current of 1.3 amps, and a maximum current of 50 amps. The R2001
is a “D”-wind motor with a KV of 2,400, a resistance of 0.02 ohm, a
no-load current of 2.5 amps, and a maximum current of 70 amps.
Each motor is rated at 1.2 kilowatts (with adequate cooling), and
the maximum rpm is limited to 50,000. Each motor has a 5mm shaft,
and the size is 34.8mm in diameter, 5,802mm in length, and 196
grams.
Although my testing is not as thorough as I’d like yet, I am
impressed with what I’ve seen and I’ve run the motors to well past
the rated 1.2 kilowatts. They are priced competitively, so give Pete a
call at MEC and check them out.
Motor-Naming Conundrum: There is no standard for naming
motors. It’s that plain and simple whether we like it or not.
I’ve gotten more E-mail messages and letters about this situation
throughout the years than anything else. People want to know why
there isn’t a standard or why the magazines haven’t made the
manufacturers do something about it (as if we could).
There are so many answers to that I won’t even attempt to sort
them out. Each manufacturer has its own reasons why it thinks its
method of naming motors is the best, and each has a good
argument for it.
The best way to find out about a motor
is to go to the manufacturer’s Web site or
one of its vendor sites and look at the
application charts most provide. Call and
ask the company if the motor you’re
considering is right for your application.
Make the personnel guide you to the right
motor if you’re confused so you don’t waste
your money. Most vendors are more than
happy to do that.
What I can do is give you some
common motor names and tell you what the
numbers mean.
• AstroFlight: Astro has been around for
longer than Bob Boucher probably wants to
think about, but his motors have been topnotch
since the beginning. Bob originally
named his engines to try to correlate to the
glow engines they would replace. If you
flew with a .25 engine, you would use an
Astro 25 motor. If you had a .40 engine, an
Astro 40 motor would do the trick, and so
on.
As things developed and motors
improved along with gearing, etc., this
system didn’t hold up; I’ve flown 25- and
40-size models with Astro 15G motors.
But AstroFlight has continued to use this
designation, and there’s something to be
said for consistency; everyone has come to
know the various sizes and capabilities of
the motors by their designations.
• Graupner: You are probably familiar
with the Speed 400, 550, 600, and 700
series of ferrite motors. These are named
by the diameter of the motors. That
doesn’t tell you much, but these motors
have been around for so long that
modelers have come to know what they’re
meant for.
The most common size is probably the
Speed 400, which comes in 4.8-, 6.0-, and
7.2-volt versions and even higher if you
dig deep enough. The motor is actually
38mm in diameter, but the numbers are
rounded up. When you hear someone
speak of a 380 motor, he or she is using
Mabuchi’s actual size.
The name will get you the size of the
motor, but you’ll have to search further for
the voltage rating, and other information.
Hobby Lobby’s Web site and catalog have
a good set of charts to show you the
constants for each motor in this class and
appropriate applications.
• Mega: These motors are designated by the
size of the armature and the number of
turns. Many companies have used similar
methods, but they use the size of the case
instead of the armature.
A Mega Acn 22/45/2 means the
armature (rotor) diameter is 22mm, the
length is 45mm, and this is a two-turn
motor. For comparison, this is
approximately the same physical size as a
Speed 600 motor, and the Mega 16/15/6 is
the size of a Speed 400 motor.
By indicating the winds, some clue is
given about how “hot” the motor is. You
need to consult the charts and check for
proper application unless someone gives
you a recommendation.
• Hacker: This company’s motors are
named using the length of the rotor and the
number of winds. If you see a B40 8XL,
you know the rotor is 40mm long, the
motor has eight turns, and the motor’s body
is extra long. Hacker uses S, L, and XL for
length; the longer the body, the more torque
the motor can produce.
Sometimes you’ll see one of these
power plants listed as B50 12XL+4.4:1.
That means the armature is 50mm in
diameter, and the motor has 12 turns in an
extra-long case attached to a planetary
gearbox geared 4.4:1.
• AXI: The diameter and length of the
armature along with the number of turns are
used to designate these motors’ sizes. When
you see a 2820/12, you know its rotor
diameter is 28mm, the length is 20mm, and
the number of turns is 12.
Although there is no standard for
naming motors, there is some consensus
among manufacturers that the numbers
should represent the size and number of
turns. They don’t make it apparent whether
they’re referring to case size, armature size,
or a bit of both, but the armature is close to
the case size, so it’s not all that significant.
(We’re not being engineers here.)
Some companies also list the KV at the
end of their designations. I’m still a
believer in the computer modeling
programs such as ElectriCalc and MotoCalc
to help select motors. Armed with the
motor constants, you can plug them into
these programs and get a general idea of
what they will do in your application. You
can also compare various winds side by
side in a printout to see how they affect
your outcome.
There are more motors on the market
today than I would have dreamed, so it can
be daunting to sort through them all. The
most important thing is to ask your vendor
if you have questions! If that company
can’t answer them, find one that can.
Microflight Info: This is a bit out of my
area of expertise, but I’ve gotten inquiriesnewsletter, edited by John Worth, that Air
Age used to publish. Air Age discontinued
the publication, but John is hard at work
doing an exceptional online subscription
version called RC Micro World.
The price is $12, and you can read this
publication online or download it in PDF
format from www.cloud9rc.com. It’s every
bit as good as it used to be (maybe even
better), and I encourage you to support John’s
efforts.
Microflight has come a long way and
adds another dimension to your electricpower
flying—especially if you live in the
colder sections of the country and have access
to some indoor facilities. Check it out!
Final Approach: We’re in the depths of
winter, so you may be busy building those
projects for spring. A photo shows a Thunder
Tiger Christen Eagle 3-D foamie I’ll be
finishing soon, so look for more about it in
the near future.
Send your pictures and info to me, and
shoot digital photos in high resolution for
publication. Also send in your building tips
and tricks; they are popular judging from the
reader mail I’m getting. MA
Sources:
AstroFlight Inc.
13311 Beach Ave.
Marina Del Rey CA 90292
(310) 821-6242
(310) 822-6637
[email protected]
www.astroflight.com
Model Electronics Corporation
11512-155 Ave. SE
Renton WA 98059
(866) 507-9956 (excluding Canada)
(425) 255-4269
Fax: (425) 255-1558
[email protected]
www.modelelectronicscorp.com
Hobby Lobby International, Inc. (for
Graupner, AXI products)
5614 Franklin Pike Cir.
Brentwood TN 37027
(615) 373-1444
Fax: (615) 377-6948
www.hobby-lobby.com
West Mountain Radio
18 Sheehan Ave.
Norwalk CT 06854
(203) 853-8080
Fax: (203) 299-0232
www.westmountainradio.com
Edition: Model Aviation - 2006/02
Page Numbers: 107,108,110,112
“Covering: UltraCote. The front half of
the cowl is covered in Sig AeroKote ironed
on over the ABS cowl (worked very well
with low heat). I printed the decals on my
ink-jet printer using Micro-Mark water
slide decal paper. The decals were sealed
with Krylon Crystal Clear. The color
scheme is based on the full-scale ‘Furias’
Reno Racer.
“Building detail: The laser-cut kit went
together almost flawlessly. Wood quality
was excellent. I lightened all plywood
formers and wing ribs. I didn’t use any
other weight-saving techniques to bring my
e-powered Sea Fury
in 1/2-pound lighter
than my friend’s
wet-powered
example.
“I did create an
access hatch for the
power pack. There
is plenty of room
for up to a 9S3P
pack. I intentionally
moved the elevator
horn to the top so
that it would pull
for up-elevator, as I
anticipated some
high-‘G’ Reno-type
turns.
“Flying: Wow!
It was off the
ground at half
throttle. Two clicks
of up-elevator and
four of right aileron,
and it was flying
Walt Thyng describes his fabulous Direct Connections Sea Fury
February 2006 107
Electrics Greg Gimlick | [email protected]
With an all-up weight of 8.25 pounds, Walt Thyng’s gorgeous AXI 4130/20 motorpowered
Sea Fury is lighter than his friend’s 1.20-powered version.
Walt used off-the-shelf mailbox mounting brackets to mount the
AXI in the Sea Fury. It’s a simple and easy method.
BEFORE I GET going this month I want
to thank all who wrote and called during my
recent illness. What a joy to find out how
many modelers really care about one
another.
Rest assured I am on the mend and
getting better all the time. I’m back to flying
and building, so my wife figures I’ll live
now. Thank you again and I hope to see you
at many events this year.
Featured Model of the Month: Walt Thyng
has been building some incredible Electrics
for a long time, so it’s always great to see
something show up in my inbox from him.
Following is Walt’s description of his
Direct Connections Sea Fury, which spans
64 inches and has an area of 791 square
inches.
“The all-up weight is 8.25 pounds with
D&B mechanical retracts powered by a
Hitec retract servo.
“Radio: Transmitter and receiver are
Airtronics. The receiver battery is a fourcell
CP-1300 Sanyo Ni-Cd pack.
“Servos: I’m using two Hitec HS-81s
for the ailerons and Futaba standards for the
rudder and elevator.
“Pushrods: Dave Brown Products
fiberglass with 4-40 rods and clevises.
There are no flaps since the full-scale
version had them removed for weight and
streamlining.
“Power system: I’m using an AXI
4130/20 Outrunner motor, a Hacker Master
77 opto ESC, a 9S2P Thunder Power 2100
Li-Poly battery pack, and an APC-E 14 x 12
propeller. Static amp draw is 41.
straight and true. (I later added 3° of
downthrust.) This is a very stable and fast
flier.
“I had originally planned to go to a
10S3P pack and larger prop to get a 90+
mph airspeed, which would be close to onesixth
of the top speed obtained by the real
Furias. I don’t think I need to do that.
“Flight characteristic are typical of a
warbird. Rolls are fairly axial with careful
use of elevator. Loops can be any size you
want. The stall is a gentle straight-ahead
drop of the nose. Slow flight produces a
crawl with controls effective right up to the
stall. I haven’t gotten it to spin after eight
flights.
“This is one great-flying airplane that
handles better than my Top Flite P-47.”
Building Tip: I’m going to use a photo of
Walt’s motor mount for a tip because it’s
just so easy. The photo tells it all; it’s a
simple mailbox mounting kit available from
Also included in this column:
108 MODEL AVIATION
West Mountain Radio’s single-cell clamp allows testing of
individual cells. It’s shown testing a cell with the CBA II.
Canadian-made Merlin brushless motors. The labeled one is the
R2000 “Y”-wind motor, and the other is the R2001 “D” wind.
Thunder Tiger’s 3-D foam Christen Eagle is quick to build and good in quality.
most of the big home-improvement stores. Full adjustability and
light weight make it worth trying the next time you’re in a pinch for
a mount.
Cool Tool: I’ve written about using solderless power tubes for my
Ni-Cd and NiMH packs because I hate to solder and like to be able
to check on the condition of individual cells. The problem it creates
is how to attach a single cell to an analyzer such as West Mountain
Radio’s CBA II that I use all the time.
I’ve seen all sorts of elaborate homemade fixtures with which to
do this, but they all seemed like too much work and too
complicated. However, West Mountain Radio has made a single-cell
clamp, complete with connectors. Now all I have to do is stick the
cell in and start testing. This is a great tool!
New Brushless Motors: In the last column I teased you with a
mention of some new brushless motors that would soon be available
from Model Electronics Corporation (MEC). They are now
available.
Although I had hoped to have one in a model by now, all I’ve
managed to do is test them on the bench. So far they have stood up
well to my bench abuse, and I have every reason to believe that they
will perform well in the 1/4-scale Gee Bee R-2 I’m converting.
Okay, enough teasing; these are Merlin motors made in Canada,
and they come in two variations. The R2000 is a “Y”-wind motor
with 1,560 rpm/volts (KV), a resistance of 0.06 ohm, a no-load
current of 1.3 amps, and a maximum current of 50 amps. The R2001
is a “D”-wind motor with a KV of 2,400, a resistance of 0.02 ohm, a
no-load current of 2.5 amps, and a maximum current of 70 amps.
Each motor is rated at 1.2 kilowatts (with adequate cooling), and
the maximum rpm is limited to 50,000. Each motor has a 5mm shaft,
and the size is 34.8mm in diameter, 5,802mm in length, and 196
grams.
Although my testing is not as thorough as I’d like yet, I am
impressed with what I’ve seen and I’ve run the motors to well past
the rated 1.2 kilowatts. They are priced competitively, so give Pete a
call at MEC and check them out.
Motor-Naming Conundrum: There is no standard for naming
motors. It’s that plain and simple whether we like it or not.
I’ve gotten more E-mail messages and letters about this situation
throughout the years than anything else. People want to know why
there isn’t a standard or why the magazines haven’t made the
manufacturers do something about it (as if we could).
There are so many answers to that I won’t even attempt to sort
them out. Each manufacturer has its own reasons why it thinks its
method of naming motors is the best, and each has a good
argument for it.
The best way to find out about a motor
is to go to the manufacturer’s Web site or
one of its vendor sites and look at the
application charts most provide. Call and
ask the company if the motor you’re
considering is right for your application.
Make the personnel guide you to the right
motor if you’re confused so you don’t waste
your money. Most vendors are more than
happy to do that.
What I can do is give you some
common motor names and tell you what the
numbers mean.
• AstroFlight: Astro has been around for
longer than Bob Boucher probably wants to
think about, but his motors have been topnotch
since the beginning. Bob originally
named his engines to try to correlate to the
glow engines they would replace. If you
flew with a .25 engine, you would use an
Astro 25 motor. If you had a .40 engine, an
Astro 40 motor would do the trick, and so
on.
As things developed and motors
improved along with gearing, etc., this
system didn’t hold up; I’ve flown 25- and
40-size models with Astro 15G motors.
But AstroFlight has continued to use this
designation, and there’s something to be
said for consistency; everyone has come to
know the various sizes and capabilities of
the motors by their designations.
• Graupner: You are probably familiar
with the Speed 400, 550, 600, and 700
series of ferrite motors. These are named
by the diameter of the motors. That
doesn’t tell you much, but these motors
have been around for so long that
modelers have come to know what they’re
meant for.
The most common size is probably the
Speed 400, which comes in 4.8-, 6.0-, and
7.2-volt versions and even higher if you
dig deep enough. The motor is actually
38mm in diameter, but the numbers are
rounded up. When you hear someone
speak of a 380 motor, he or she is using
Mabuchi’s actual size.
The name will get you the size of the
motor, but you’ll have to search further for
the voltage rating, and other information.
Hobby Lobby’s Web site and catalog have
a good set of charts to show you the
constants for each motor in this class and
appropriate applications.
• Mega: These motors are designated by the
size of the armature and the number of
turns. Many companies have used similar
methods, but they use the size of the case
instead of the armature.
A Mega Acn 22/45/2 means the
armature (rotor) diameter is 22mm, the
length is 45mm, and this is a two-turn
motor. For comparison, this is
approximately the same physical size as a
Speed 600 motor, and the Mega 16/15/6 is
the size of a Speed 400 motor.
By indicating the winds, some clue is
given about how “hot” the motor is. You
need to consult the charts and check for
proper application unless someone gives
you a recommendation.
• Hacker: This company’s motors are
named using the length of the rotor and the
number of winds. If you see a B40 8XL,
you know the rotor is 40mm long, the
motor has eight turns, and the motor’s body
is extra long. Hacker uses S, L, and XL for
length; the longer the body, the more torque
the motor can produce.
Sometimes you’ll see one of these
power plants listed as B50 12XL+4.4:1.
That means the armature is 50mm in
diameter, and the motor has 12 turns in an
extra-long case attached to a planetary
gearbox geared 4.4:1.
• AXI: The diameter and length of the
armature along with the number of turns are
used to designate these motors’ sizes. When
you see a 2820/12, you know its rotor
diameter is 28mm, the length is 20mm, and
the number of turns is 12.
Although there is no standard for
naming motors, there is some consensus
among manufacturers that the numbers
should represent the size and number of
turns. They don’t make it apparent whether
they’re referring to case size, armature size,
or a bit of both, but the armature is close to
the case size, so it’s not all that significant.
(We’re not being engineers here.)
Some companies also list the KV at the
end of their designations. I’m still a
believer in the computer modeling
programs such as ElectriCalc and MotoCalc
to help select motors. Armed with the
motor constants, you can plug them into
these programs and get a general idea of
what they will do in your application. You
can also compare various winds side by
side in a printout to see how they affect
your outcome.
There are more motors on the market
today than I would have dreamed, so it can
be daunting to sort through them all. The
most important thing is to ask your vendor
if you have questions! If that company
can’t answer them, find one that can.
Microflight Info: This is a bit out of my
area of expertise, but I’ve gotten inquiriesnewsletter, edited by John Worth, that Air
Age used to publish. Air Age discontinued
the publication, but John is hard at work
doing an exceptional online subscription
version called RC Micro World.
The price is $12, and you can read this
publication online or download it in PDF
format from www.cloud9rc.com. It’s every
bit as good as it used to be (maybe even
better), and I encourage you to support John’s
efforts.
Microflight has come a long way and
adds another dimension to your electricpower
flying—especially if you live in the
colder sections of the country and have access
to some indoor facilities. Check it out!
Final Approach: We’re in the depths of
winter, so you may be busy building those
projects for spring. A photo shows a Thunder
Tiger Christen Eagle 3-D foamie I’ll be
finishing soon, so look for more about it in
the near future.
Send your pictures and info to me, and
shoot digital photos in high resolution for
publication. Also send in your building tips
and tricks; they are popular judging from the
reader mail I’m getting. MA
Sources:
AstroFlight Inc.
13311 Beach Ave.
Marina Del Rey CA 90292
(310) 821-6242
(310) 822-6637
[email protected]
www.astroflight.com
Model Electronics Corporation
11512-155 Ave. SE
Renton WA 98059
(866) 507-9956 (excluding Canada)
(425) 255-4269
Fax: (425) 255-1558
[email protected]
www.modelelectronicscorp.com
Hobby Lobby International, Inc. (for
Graupner, AXI products)
5614 Franklin Pike Cir.
Brentwood TN 37027
(615) 373-1444
Fax: (615) 377-6948
www.hobby-lobby.com
West Mountain Radio
18 Sheehan Ave.
Norwalk CT 06854
(203) 853-8080
Fax: (203) 299-0232
www.westmountainradio.com
Edition: Model Aviation - 2006/02
Page Numbers: 107,108,110,112
“Covering: UltraCote. The front half of
the cowl is covered in Sig AeroKote ironed
on over the ABS cowl (worked very well
with low heat). I printed the decals on my
ink-jet printer using Micro-Mark water
slide decal paper. The decals were sealed
with Krylon Crystal Clear. The color
scheme is based on the full-scale ‘Furias’
Reno Racer.
“Building detail: The laser-cut kit went
together almost flawlessly. Wood quality
was excellent. I lightened all plywood
formers and wing ribs. I didn’t use any
other weight-saving techniques to bring my
e-powered Sea Fury
in 1/2-pound lighter
than my friend’s
wet-powered
example.
“I did create an
access hatch for the
power pack. There
is plenty of room
for up to a 9S3P
pack. I intentionally
moved the elevator
horn to the top so
that it would pull
for up-elevator, as I
anticipated some
high-‘G’ Reno-type
turns.
“Flying: Wow!
It was off the
ground at half
throttle. Two clicks
of up-elevator and
four of right aileron,
and it was flying
Walt Thyng describes his fabulous Direct Connections Sea Fury
February 2006 107
Electrics Greg Gimlick | [email protected]
With an all-up weight of 8.25 pounds, Walt Thyng’s gorgeous AXI 4130/20 motorpowered
Sea Fury is lighter than his friend’s 1.20-powered version.
Walt used off-the-shelf mailbox mounting brackets to mount the
AXI in the Sea Fury. It’s a simple and easy method.
BEFORE I GET going this month I want
to thank all who wrote and called during my
recent illness. What a joy to find out how
many modelers really care about one
another.
Rest assured I am on the mend and
getting better all the time. I’m back to flying
and building, so my wife figures I’ll live
now. Thank you again and I hope to see you
at many events this year.
Featured Model of the Month: Walt Thyng
has been building some incredible Electrics
for a long time, so it’s always great to see
something show up in my inbox from him.
Following is Walt’s description of his
Direct Connections Sea Fury, which spans
64 inches and has an area of 791 square
inches.
“The all-up weight is 8.25 pounds with
D&B mechanical retracts powered by a
Hitec retract servo.
“Radio: Transmitter and receiver are
Airtronics. The receiver battery is a fourcell
CP-1300 Sanyo Ni-Cd pack.
“Servos: I’m using two Hitec HS-81s
for the ailerons and Futaba standards for the
rudder and elevator.
“Pushrods: Dave Brown Products
fiberglass with 4-40 rods and clevises.
There are no flaps since the full-scale
version had them removed for weight and
streamlining.
“Power system: I’m using an AXI
4130/20 Outrunner motor, a Hacker Master
77 opto ESC, a 9S2P Thunder Power 2100
Li-Poly battery pack, and an APC-E 14 x 12
propeller. Static amp draw is 41.
straight and true. (I later added 3° of
downthrust.) This is a very stable and fast
flier.
“I had originally planned to go to a
10S3P pack and larger prop to get a 90+
mph airspeed, which would be close to onesixth
of the top speed obtained by the real
Furias. I don’t think I need to do that.
“Flight characteristic are typical of a
warbird. Rolls are fairly axial with careful
use of elevator. Loops can be any size you
want. The stall is a gentle straight-ahead
drop of the nose. Slow flight produces a
crawl with controls effective right up to the
stall. I haven’t gotten it to spin after eight
flights.
“This is one great-flying airplane that
handles better than my Top Flite P-47.”
Building Tip: I’m going to use a photo of
Walt’s motor mount for a tip because it’s
just so easy. The photo tells it all; it’s a
simple mailbox mounting kit available from
Also included in this column:
108 MODEL AVIATION
West Mountain Radio’s single-cell clamp allows testing of
individual cells. It’s shown testing a cell with the CBA II.
Canadian-made Merlin brushless motors. The labeled one is the
R2000 “Y”-wind motor, and the other is the R2001 “D” wind.
Thunder Tiger’s 3-D foam Christen Eagle is quick to build and good in quality.
most of the big home-improvement stores. Full adjustability and
light weight make it worth trying the next time you’re in a pinch for
a mount.
Cool Tool: I’ve written about using solderless power tubes for my
Ni-Cd and NiMH packs because I hate to solder and like to be able
to check on the condition of individual cells. The problem it creates
is how to attach a single cell to an analyzer such as West Mountain
Radio’s CBA II that I use all the time.
I’ve seen all sorts of elaborate homemade fixtures with which to
do this, but they all seemed like too much work and too
complicated. However, West Mountain Radio has made a single-cell
clamp, complete with connectors. Now all I have to do is stick the
cell in and start testing. This is a great tool!
New Brushless Motors: In the last column I teased you with a
mention of some new brushless motors that would soon be available
from Model Electronics Corporation (MEC). They are now
available.
Although I had hoped to have one in a model by now, all I’ve
managed to do is test them on the bench. So far they have stood up
well to my bench abuse, and I have every reason to believe that they
will perform well in the 1/4-scale Gee Bee R-2 I’m converting.
Okay, enough teasing; these are Merlin motors made in Canada,
and they come in two variations. The R2000 is a “Y”-wind motor
with 1,560 rpm/volts (KV), a resistance of 0.06 ohm, a no-load
current of 1.3 amps, and a maximum current of 50 amps. The R2001
is a “D”-wind motor with a KV of 2,400, a resistance of 0.02 ohm, a
no-load current of 2.5 amps, and a maximum current of 70 amps.
Each motor is rated at 1.2 kilowatts (with adequate cooling), and
the maximum rpm is limited to 50,000. Each motor has a 5mm shaft,
and the size is 34.8mm in diameter, 5,802mm in length, and 196
grams.
Although my testing is not as thorough as I’d like yet, I am
impressed with what I’ve seen and I’ve run the motors to well past
the rated 1.2 kilowatts. They are priced competitively, so give Pete a
call at MEC and check them out.
Motor-Naming Conundrum: There is no standard for naming
motors. It’s that plain and simple whether we like it or not.
I’ve gotten more E-mail messages and letters about this situation
throughout the years than anything else. People want to know why
there isn’t a standard or why the magazines haven’t made the
manufacturers do something about it (as if we could).
There are so many answers to that I won’t even attempt to sort
them out. Each manufacturer has its own reasons why it thinks its
method of naming motors is the best, and each has a good
argument for it.
The best way to find out about a motor
is to go to the manufacturer’s Web site or
one of its vendor sites and look at the
application charts most provide. Call and
ask the company if the motor you’re
considering is right for your application.
Make the personnel guide you to the right
motor if you’re confused so you don’t waste
your money. Most vendors are more than
happy to do that.
What I can do is give you some
common motor names and tell you what the
numbers mean.
• AstroFlight: Astro has been around for
longer than Bob Boucher probably wants to
think about, but his motors have been topnotch
since the beginning. Bob originally
named his engines to try to correlate to the
glow engines they would replace. If you
flew with a .25 engine, you would use an
Astro 25 motor. If you had a .40 engine, an
Astro 40 motor would do the trick, and so
on.
As things developed and motors
improved along with gearing, etc., this
system didn’t hold up; I’ve flown 25- and
40-size models with Astro 15G motors.
But AstroFlight has continued to use this
designation, and there’s something to be
said for consistency; everyone has come to
know the various sizes and capabilities of
the motors by their designations.
• Graupner: You are probably familiar
with the Speed 400, 550, 600, and 700
series of ferrite motors. These are named
by the diameter of the motors. That
doesn’t tell you much, but these motors
have been around for so long that
modelers have come to know what they’re
meant for.
The most common size is probably the
Speed 400, which comes in 4.8-, 6.0-, and
7.2-volt versions and even higher if you
dig deep enough. The motor is actually
38mm in diameter, but the numbers are
rounded up. When you hear someone
speak of a 380 motor, he or she is using
Mabuchi’s actual size.
The name will get you the size of the
motor, but you’ll have to search further for
the voltage rating, and other information.
Hobby Lobby’s Web site and catalog have
a good set of charts to show you the
constants for each motor in this class and
appropriate applications.
• Mega: These motors are designated by the
size of the armature and the number of
turns. Many companies have used similar
methods, but they use the size of the case
instead of the armature.
A Mega Acn 22/45/2 means the
armature (rotor) diameter is 22mm, the
length is 45mm, and this is a two-turn
motor. For comparison, this is
approximately the same physical size as a
Speed 600 motor, and the Mega 16/15/6 is
the size of a Speed 400 motor.
By indicating the winds, some clue is
given about how “hot” the motor is. You
need to consult the charts and check for
proper application unless someone gives
you a recommendation.
• Hacker: This company’s motors are
named using the length of the rotor and the
number of winds. If you see a B40 8XL,
you know the rotor is 40mm long, the
motor has eight turns, and the motor’s body
is extra long. Hacker uses S, L, and XL for
length; the longer the body, the more torque
the motor can produce.
Sometimes you’ll see one of these
power plants listed as B50 12XL+4.4:1.
That means the armature is 50mm in
diameter, and the motor has 12 turns in an
extra-long case attached to a planetary
gearbox geared 4.4:1.
• AXI: The diameter and length of the
armature along with the number of turns are
used to designate these motors’ sizes. When
you see a 2820/12, you know its rotor
diameter is 28mm, the length is 20mm, and
the number of turns is 12.
Although there is no standard for
naming motors, there is some consensus
among manufacturers that the numbers
should represent the size and number of
turns. They don’t make it apparent whether
they’re referring to case size, armature size,
or a bit of both, but the armature is close to
the case size, so it’s not all that significant.
(We’re not being engineers here.)
Some companies also list the KV at the
end of their designations. I’m still a
believer in the computer modeling
programs such as ElectriCalc and MotoCalc
to help select motors. Armed with the
motor constants, you can plug them into
these programs and get a general idea of
what they will do in your application. You
can also compare various winds side by
side in a printout to see how they affect
your outcome.
There are more motors on the market
today than I would have dreamed, so it can
be daunting to sort through them all. The
most important thing is to ask your vendor
if you have questions! If that company
can’t answer them, find one that can.
Microflight Info: This is a bit out of my
area of expertise, but I’ve gotten inquiriesnewsletter, edited by John Worth, that Air
Age used to publish. Air Age discontinued
the publication, but John is hard at work
doing an exceptional online subscription
version called RC Micro World.
The price is $12, and you can read this
publication online or download it in PDF
format from www.cloud9rc.com. It’s every
bit as good as it used to be (maybe even
better), and I encourage you to support John’s
efforts.
Microflight has come a long way and
adds another dimension to your electricpower
flying—especially if you live in the
colder sections of the country and have access
to some indoor facilities. Check it out!
Final Approach: We’re in the depths of
winter, so you may be busy building those
projects for spring. A photo shows a Thunder
Tiger Christen Eagle 3-D foamie I’ll be
finishing soon, so look for more about it in
the near future.
Send your pictures and info to me, and
shoot digital photos in high resolution for
publication. Also send in your building tips
and tricks; they are popular judging from the
reader mail I’m getting. MA
Sources:
AstroFlight Inc.
13311 Beach Ave.
Marina Del Rey CA 90292
(310) 821-6242
(310) 822-6637
[email protected]
www.astroflight.com
Model Electronics Corporation
11512-155 Ave. SE
Renton WA 98059
(866) 507-9956 (excluding Canada)
(425) 255-4269
Fax: (425) 255-1558
[email protected]
www.modelelectronicscorp.com
Hobby Lobby International, Inc. (for
Graupner, AXI products)
5614 Franklin Pike Cir.
Brentwood TN 37027
(615) 373-1444
Fax: (615) 377-6948
www.hobby-lobby.com
West Mountain Radio
18 Sheehan Ave.
Norwalk CT 06854
(203) 853-8080
Fax: (203) 299-0232
www.westmountainradio.com