Using lead-acid batteries as a DC charger power source
The Battery Clinic Red Scholefield | [email protected]
Also included in this column:
• A123 as a starter battery
• A123 now in a smaller size
• Electric racing
• The CG blues
• Florida electric fly-ins
Right: A 4S A123 pack in the author’s Ultimate biplane brings
the CG into the proper location.
Above: The A123 four-cell pack makes a great starter battery.
The World Models’ Sky Raider was
converted to electric power for racing.
Building a four-cell pack from A123 cells. C: Cells removed from shell. D: Paper sleeve is
saved for pack assembly. E: Pair of cells folded to form two sticks and paper sleeve over each
stick. F: Completed pack with heat shrink.
I GET MANY questions about how many
charges someone can get out of a lead-acid
battery. It comes down to the simple matter of
how many watt-hours are available from the
battery.
A standard field-box battery that many use
for starting and fuel pumps is 12 volts, 7 Ah.
Thus 12 multiplied by 7 gives us 84 watthours.
To charge, say, a 3S 2100 mAh Li-Poly
pack would take the nominal 11.1 volts
multiplied by the capacity of 2.1 A, to come
up with 23.3 watt-hours.
However, since charging is not 100%
efficient, nor are the chargers we use, we
divide approximately 60%-70% of the leadacid
watt-hours, in this case 55 watt-hours, by
the watt-hours to charge the 3S pack and come
up with roughly 2.4 charges. Your mileage
may vary, but this gives you an approximation
of how many charges you can get.
You will get more charges if you don’t
discharge the Li-Poly pack all the way. The
number of charges you get will also increase
somewhat as the charge rate is reduced. Did I
claim it was simple?
A123 Does Duty as a Starter Battery: I’m so
110 MODEL AVIATION
A B D
C E
F
03sig4.QXD 1/25/08 8:28 AM Page 110March 2008 111
This Giant Scale Monocoupe was converted to electric power.
Millennium R/C displays its new line of small aerobatic ARFs at the Zephyrhills FL
electric fly-in.
wrapped up in electric flying that something
escaped me. A flying friend, Jerry Dittmar,
came up with a neat power pack for his
Sullivan starter (one of those bulky things you
jam into the spinner on your glow-powered
model to start it).
Jerry made a 4S pack using A123 cells. It
gives his starter lots of zip and nicely handled
much of the starting at one of our recent Club
40 races.
A Smaller A123: The size of the 2300 A123
cells have dictated that they are useful in larger
models: 40 size and up. They are now
available in the 18650 size. (The designation
translates to 18mm in diameter and 65mm
long. The 2300 cells are designated as 26650.)
Although the new cells are quoted as 1.1
Ah, my preliminary testing at a 1-amp
discharge shows them to be roughly 1.0 Ah.
Nevertheless, these packs offer those who
build smaller models the safety and long life
inherent in the A123 technology.
These cells are used in the Black & Decker
VPX series of cordless power tools. I bought a
two-cell pack at Lowe’s for $20. You will
need two to make a four-cell (14-volt) pack.
The two-cell pack is easy to remove from
its shell; just peel back the label and there are
two latches on the connector end. Lift these a
bit to release the connector end, and then slide
out the two cells. Remove the paper sleeve by
uncrimping them; you want to save it to use
when you reassemble the two cells into a stick.
Bend the two cells to make a stick, and
then slide one paper sleeve over the middle,
cutting a small 1/8 x 1/4-inch hole over where
the tab between the cells is located so you can
solder the balance connector. A drop of thin
cyanoacrylate at both ends of the sleeve will
secure the pack.
With the two sticks side by side, solder a
strap across one end and attach the power lead
to the other. On these, unlike the other A123
cells, the button is positive and the can is
negative. A bit of cyanoacrylate will hold
the two sticks together. Put a shrink sleeve
over the whole pack and you are finished.
The weight comes out to 6.2 ounces,
which is only an ounce heavier than a 3S
2100 Li-Poly pack that it will physically
replace. The new pack is only half the
capacity, but when you consider that you
can charge it in 20 minutes with a Cellpro
unit, your overall flying time is not
significantly compromised.
With $40 invested in the A123 4S 1000
mAh pack, it is approximately half the
price of a 3S 2100 mAh Li-Poly pack. And
you will probably get many more cycles
from it.
Electric Racing on the Horizon? Club 40
races, which I mentioned earlier, are
growing in popularity in this part of
Florida. A couple club members converted
the standard Club 40 racer (The World
Models Sky Raider Mach II ARF),
powered by an O.S. 40LA, to electric
using an AXi 2826/10 motor with a 4S
4200 Li-Poly pack. At 820 watts it turns an
APC 10 x 10 at 10,200 rpm.
While the electric-powered version
could not be flown in competition with the
glow-powered models, a demo flight
against one of the top racers showed it to
be quite competitive—enough so that it
appeared that pilot skill would be the
deciding factor in a real race.
Got CG Blues With Your Model? I
swapped an Aero Technologies Ultimate
300 Blue Hawk for some A123 cells. The
original owner had a problem with the
model when the instructions called for a
CG that was 21/4 inches too far back. It
ended up being a tail-heavy dog.
I found that it took 10 ounces of lead to
bring the CG in. There was no way I
would do that; lead in models is against
my religion. What was I to do?
I found that if I made two two-cell
A123 packs, they would fit nicely under
the cowl as far forward as they could be.
They are difficult to get into and out of the
model without removing the spinner,
propeller, and cowl, so I built them in with
a charge/balancing jack that is accessible
to connect to my Cellpro charger/balancer.
That will give me a 45-minute recharge
capability, and because there is no
recorded incident with A123 cells, I feel
reasonably safe leaving them in the model
as I did flight packs for the past half
century.
First flights confirm that the CG is right
03sig4.QXD 1/25/08 8:14 AM Page 111112 MODEL AVIATION
where it belongs. The Blue Hawk is powered
by an AXi 2808/24 motor and a Graupner 9 x
6 propeller.
Florida Electric Fly-Ins Grow: Electric flyins
are growing at a rapid rate here in Florida.
One in late October at Zephyrhills, hosted by
the Can-Am Flyers Inc., had many fliers and
well more than 100 models. The variety was
awesome, including everything from park
flyers to Giant Scale International Miniature
Aerobatic Club 3-D aircraft.
I love what can be done with Scale models
by tucking a motor in them where you have
no cylinder heads or mufflers with which to
contend. In one of the photos is a beautiful
Monocoupe by John Uhle that hides a Hacker
B50-7XL motor with a 6.7:1 gearbox to swing
an 18 x 8 APC-E propeller.
At the Zephyrhills meet I saw a new
company in the vendor’s area. Millennium
R/C, based in Orlando, Florida, features a line
of kits and ARFs of some neat little (don’t
leave home without one) aerobatic models.
They are offered as laser-cut kits, employing a
lot of carbon fiber, PARFs (Partially Almost
Ready to Flys), and ARFs.
But there is more. Those models are
offered as full-house packages, complete with
a DNC Power 20C 1350 mAh, 11.1-volt Li-
Poly battery; a Himax 2025-4200 brushless
motor; an aluminum gearbox, 10T, and
12T/2.0mm pinion gears; 70-spur gear; three
servos; a Castle Creations Thunderbird-18
ESC; a Deans connector set; and heat-shrink
tubing. I saw some talented pilots fly these
models, and they will do everything you want
in a restricted area.
In another vendor booth I found a great
supplier of Velcro that has become the
fastener of choice in many electric-powered
models. Lu Mahoney, the wife of an active
modeler, has handy items such as ONEWRAP
back-to-back hook-and-loop straps
that are ideal for holding down components
and battery packs.
Along with this is a commercial-grade 87S
hook material that—when attached to the
airframe with slow cyanoacrylate, Cyberbond
medium epoxy, or Goop—will hold
everything in place. Lu offers an installation
kit, which includes a 24 x 2-inch 87S hook, 36
x 2-inch ONE-WRAP, 36 x 1-inch ONEWRAP,
and 36 x 1/2-inch ONE-WRAP.
Bloody Hands and Ugly Planes: I got some
pithy comments from a couple readers, one of
whom was offended by the “blood and gore”
shown in my November column. That
message read, “Isn’t it common knowledge
that if you stick your hand in a rotating
propeller that you will get cut?”
The other in the same thread read:
“Seems everything is an ugly sight in
Red’s write-ups, just check out that bird in
the pix next to the hand. And that’s not the
first ugly plane Red has shown, those
planes just don’t deserve magazine page
attention!”
There were only two negative comments
about the blood-and-gore issue. It was
overwhelmingly known that it was a good
object lesson in safety.
To address the ugly models, much of what
goes into a column of this type is driven by
letters and questions from readers or from
questions on forums regarding electric flight.
One of the more popular questions is how to
modify (the name of your favorite glowpowered
airplane here) for electric. The
simplest answer is to show how someone
modified theirs with good results.
Send in those pictures (with details) of
your electric-flight conversions, and maybe
you too can have an ugly airplane published in
MA.
That’s it for this month. Keep smiling and
maybe the snow will melt soon. Better yet,
take a vacation and visit the Sunshine State,
where flying is at its best this time of the year.
Support your US Postal Service and send
an SASE if you want a personalized answer.
The Battery Clinic is located at 12219 NW 9th
Ln., Newberry FL 32669. But E-mail is faster
and saves a tree. (Oh, sorry, we hate trees;
they eat airplanes. MA
Sources:
Lu Mahoney
[email protected]
Millennium R/C
(407) 208-9745
03sig4.QXD 1/25/08 8:14 AM Page 112
Edition: Model Aviation - 2008/03
Page Numbers: 110,111,112
Edition: Model Aviation - 2008/03
Page Numbers: 110,111,112
Using lead-acid batteries as a DC charger power source
The Battery Clinic Red Scholefield | [email protected]
Also included in this column:
• A123 as a starter battery
• A123 now in a smaller size
• Electric racing
• The CG blues
• Florida electric fly-ins
Right: A 4S A123 pack in the author’s Ultimate biplane brings
the CG into the proper location.
Above: The A123 four-cell pack makes a great starter battery.
The World Models’ Sky Raider was
converted to electric power for racing.
Building a four-cell pack from A123 cells. C: Cells removed from shell. D: Paper sleeve is
saved for pack assembly. E: Pair of cells folded to form two sticks and paper sleeve over each
stick. F: Completed pack with heat shrink.
I GET MANY questions about how many
charges someone can get out of a lead-acid
battery. It comes down to the simple matter of
how many watt-hours are available from the
battery.
A standard field-box battery that many use
for starting and fuel pumps is 12 volts, 7 Ah.
Thus 12 multiplied by 7 gives us 84 watthours.
To charge, say, a 3S 2100 mAh Li-Poly
pack would take the nominal 11.1 volts
multiplied by the capacity of 2.1 A, to come
up with 23.3 watt-hours.
However, since charging is not 100%
efficient, nor are the chargers we use, we
divide approximately 60%-70% of the leadacid
watt-hours, in this case 55 watt-hours, by
the watt-hours to charge the 3S pack and come
up with roughly 2.4 charges. Your mileage
may vary, but this gives you an approximation
of how many charges you can get.
You will get more charges if you don’t
discharge the Li-Poly pack all the way. The
number of charges you get will also increase
somewhat as the charge rate is reduced. Did I
claim it was simple?
A123 Does Duty as a Starter Battery: I’m so
110 MODEL AVIATION
A B D
C E
F
03sig4.QXD 1/25/08 8:28 AM Page 110March 2008 111
This Giant Scale Monocoupe was converted to electric power.
Millennium R/C displays its new line of small aerobatic ARFs at the Zephyrhills FL
electric fly-in.
wrapped up in electric flying that something
escaped me. A flying friend, Jerry Dittmar,
came up with a neat power pack for his
Sullivan starter (one of those bulky things you
jam into the spinner on your glow-powered
model to start it).
Jerry made a 4S pack using A123 cells. It
gives his starter lots of zip and nicely handled
much of the starting at one of our recent Club
40 races.
A Smaller A123: The size of the 2300 A123
cells have dictated that they are useful in larger
models: 40 size and up. They are now
available in the 18650 size. (The designation
translates to 18mm in diameter and 65mm
long. The 2300 cells are designated as 26650.)
Although the new cells are quoted as 1.1
Ah, my preliminary testing at a 1-amp
discharge shows them to be roughly 1.0 Ah.
Nevertheless, these packs offer those who
build smaller models the safety and long life
inherent in the A123 technology.
These cells are used in the Black & Decker
VPX series of cordless power tools. I bought a
two-cell pack at Lowe’s for $20. You will
need two to make a four-cell (14-volt) pack.
The two-cell pack is easy to remove from
its shell; just peel back the label and there are
two latches on the connector end. Lift these a
bit to release the connector end, and then slide
out the two cells. Remove the paper sleeve by
uncrimping them; you want to save it to use
when you reassemble the two cells into a stick.
Bend the two cells to make a stick, and
then slide one paper sleeve over the middle,
cutting a small 1/8 x 1/4-inch hole over where
the tab between the cells is located so you can
solder the balance connector. A drop of thin
cyanoacrylate at both ends of the sleeve will
secure the pack.
With the two sticks side by side, solder a
strap across one end and attach the power lead
to the other. On these, unlike the other A123
cells, the button is positive and the can is
negative. A bit of cyanoacrylate will hold
the two sticks together. Put a shrink sleeve
over the whole pack and you are finished.
The weight comes out to 6.2 ounces,
which is only an ounce heavier than a 3S
2100 Li-Poly pack that it will physically
replace. The new pack is only half the
capacity, but when you consider that you
can charge it in 20 minutes with a Cellpro
unit, your overall flying time is not
significantly compromised.
With $40 invested in the A123 4S 1000
mAh pack, it is approximately half the
price of a 3S 2100 mAh Li-Poly pack. And
you will probably get many more cycles
from it.
Electric Racing on the Horizon? Club 40
races, which I mentioned earlier, are
growing in popularity in this part of
Florida. A couple club members converted
the standard Club 40 racer (The World
Models Sky Raider Mach II ARF),
powered by an O.S. 40LA, to electric
using an AXi 2826/10 motor with a 4S
4200 Li-Poly pack. At 820 watts it turns an
APC 10 x 10 at 10,200 rpm.
While the electric-powered version
could not be flown in competition with the
glow-powered models, a demo flight
against one of the top racers showed it to
be quite competitive—enough so that it
appeared that pilot skill would be the
deciding factor in a real race.
Got CG Blues With Your Model? I
swapped an Aero Technologies Ultimate
300 Blue Hawk for some A123 cells. The
original owner had a problem with the
model when the instructions called for a
CG that was 21/4 inches too far back. It
ended up being a tail-heavy dog.
I found that it took 10 ounces of lead to
bring the CG in. There was no way I
would do that; lead in models is against
my religion. What was I to do?
I found that if I made two two-cell
A123 packs, they would fit nicely under
the cowl as far forward as they could be.
They are difficult to get into and out of the
model without removing the spinner,
propeller, and cowl, so I built them in with
a charge/balancing jack that is accessible
to connect to my Cellpro charger/balancer.
That will give me a 45-minute recharge
capability, and because there is no
recorded incident with A123 cells, I feel
reasonably safe leaving them in the model
as I did flight packs for the past half
century.
First flights confirm that the CG is right
03sig4.QXD 1/25/08 8:14 AM Page 111112 MODEL AVIATION
where it belongs. The Blue Hawk is powered
by an AXi 2808/24 motor and a Graupner 9 x
6 propeller.
Florida Electric Fly-Ins Grow: Electric flyins
are growing at a rapid rate here in Florida.
One in late October at Zephyrhills, hosted by
the Can-Am Flyers Inc., had many fliers and
well more than 100 models. The variety was
awesome, including everything from park
flyers to Giant Scale International Miniature
Aerobatic Club 3-D aircraft.
I love what can be done with Scale models
by tucking a motor in them where you have
no cylinder heads or mufflers with which to
contend. In one of the photos is a beautiful
Monocoupe by John Uhle that hides a Hacker
B50-7XL motor with a 6.7:1 gearbox to swing
an 18 x 8 APC-E propeller.
At the Zephyrhills meet I saw a new
company in the vendor’s area. Millennium
R/C, based in Orlando, Florida, features a line
of kits and ARFs of some neat little (don’t
leave home without one) aerobatic models.
They are offered as laser-cut kits, employing a
lot of carbon fiber, PARFs (Partially Almost
Ready to Flys), and ARFs.
But there is more. Those models are
offered as full-house packages, complete with
a DNC Power 20C 1350 mAh, 11.1-volt Li-
Poly battery; a Himax 2025-4200 brushless
motor; an aluminum gearbox, 10T, and
12T/2.0mm pinion gears; 70-spur gear; three
servos; a Castle Creations Thunderbird-18
ESC; a Deans connector set; and heat-shrink
tubing. I saw some talented pilots fly these
models, and they will do everything you want
in a restricted area.
In another vendor booth I found a great
supplier of Velcro that has become the
fastener of choice in many electric-powered
models. Lu Mahoney, the wife of an active
modeler, has handy items such as ONEWRAP
back-to-back hook-and-loop straps
that are ideal for holding down components
and battery packs.
Along with this is a commercial-grade 87S
hook material that—when attached to the
airframe with slow cyanoacrylate, Cyberbond
medium epoxy, or Goop—will hold
everything in place. Lu offers an installation
kit, which includes a 24 x 2-inch 87S hook, 36
x 2-inch ONE-WRAP, 36 x 1-inch ONEWRAP,
and 36 x 1/2-inch ONE-WRAP.
Bloody Hands and Ugly Planes: I got some
pithy comments from a couple readers, one of
whom was offended by the “blood and gore”
shown in my November column. That
message read, “Isn’t it common knowledge
that if you stick your hand in a rotating
propeller that you will get cut?”
The other in the same thread read:
“Seems everything is an ugly sight in
Red’s write-ups, just check out that bird in
the pix next to the hand. And that’s not the
first ugly plane Red has shown, those
planes just don’t deserve magazine page
attention!”
There were only two negative comments
about the blood-and-gore issue. It was
overwhelmingly known that it was a good
object lesson in safety.
To address the ugly models, much of what
goes into a column of this type is driven by
letters and questions from readers or from
questions on forums regarding electric flight.
One of the more popular questions is how to
modify (the name of your favorite glowpowered
airplane here) for electric. The
simplest answer is to show how someone
modified theirs with good results.
Send in those pictures (with details) of
your electric-flight conversions, and maybe
you too can have an ugly airplane published in
MA.
That’s it for this month. Keep smiling and
maybe the snow will melt soon. Better yet,
take a vacation and visit the Sunshine State,
where flying is at its best this time of the year.
Support your US Postal Service and send
an SASE if you want a personalized answer.
The Battery Clinic is located at 12219 NW 9th
Ln., Newberry FL 32669. But E-mail is faster
and saves a tree. (Oh, sorry, we hate trees;
they eat airplanes. MA
Sources:
Lu Mahoney
[email protected]
Millennium R/C
(407) 208-9745
03sig4.QXD 1/25/08 8:14 AM Page 112
Edition: Model Aviation - 2008/03
Page Numbers: 110,111,112
Using lead-acid batteries as a DC charger power source
The Battery Clinic Red Scholefield | [email protected]
Also included in this column:
• A123 as a starter battery
• A123 now in a smaller size
• Electric racing
• The CG blues
• Florida electric fly-ins
Right: A 4S A123 pack in the author’s Ultimate biplane brings
the CG into the proper location.
Above: The A123 four-cell pack makes a great starter battery.
The World Models’ Sky Raider was
converted to electric power for racing.
Building a four-cell pack from A123 cells. C: Cells removed from shell. D: Paper sleeve is
saved for pack assembly. E: Pair of cells folded to form two sticks and paper sleeve over each
stick. F: Completed pack with heat shrink.
I GET MANY questions about how many
charges someone can get out of a lead-acid
battery. It comes down to the simple matter of
how many watt-hours are available from the
battery.
A standard field-box battery that many use
for starting and fuel pumps is 12 volts, 7 Ah.
Thus 12 multiplied by 7 gives us 84 watthours.
To charge, say, a 3S 2100 mAh Li-Poly
pack would take the nominal 11.1 volts
multiplied by the capacity of 2.1 A, to come
up with 23.3 watt-hours.
However, since charging is not 100%
efficient, nor are the chargers we use, we
divide approximately 60%-70% of the leadacid
watt-hours, in this case 55 watt-hours, by
the watt-hours to charge the 3S pack and come
up with roughly 2.4 charges. Your mileage
may vary, but this gives you an approximation
of how many charges you can get.
You will get more charges if you don’t
discharge the Li-Poly pack all the way. The
number of charges you get will also increase
somewhat as the charge rate is reduced. Did I
claim it was simple?
A123 Does Duty as a Starter Battery: I’m so
110 MODEL AVIATION
A B D
C E
F
03sig4.QXD 1/25/08 8:28 AM Page 110March 2008 111
This Giant Scale Monocoupe was converted to electric power.
Millennium R/C displays its new line of small aerobatic ARFs at the Zephyrhills FL
electric fly-in.
wrapped up in electric flying that something
escaped me. A flying friend, Jerry Dittmar,
came up with a neat power pack for his
Sullivan starter (one of those bulky things you
jam into the spinner on your glow-powered
model to start it).
Jerry made a 4S pack using A123 cells. It
gives his starter lots of zip and nicely handled
much of the starting at one of our recent Club
40 races.
A Smaller A123: The size of the 2300 A123
cells have dictated that they are useful in larger
models: 40 size and up. They are now
available in the 18650 size. (The designation
translates to 18mm in diameter and 65mm
long. The 2300 cells are designated as 26650.)
Although the new cells are quoted as 1.1
Ah, my preliminary testing at a 1-amp
discharge shows them to be roughly 1.0 Ah.
Nevertheless, these packs offer those who
build smaller models the safety and long life
inherent in the A123 technology.
These cells are used in the Black & Decker
VPX series of cordless power tools. I bought a
two-cell pack at Lowe’s for $20. You will
need two to make a four-cell (14-volt) pack.
The two-cell pack is easy to remove from
its shell; just peel back the label and there are
two latches on the connector end. Lift these a
bit to release the connector end, and then slide
out the two cells. Remove the paper sleeve by
uncrimping them; you want to save it to use
when you reassemble the two cells into a stick.
Bend the two cells to make a stick, and
then slide one paper sleeve over the middle,
cutting a small 1/8 x 1/4-inch hole over where
the tab between the cells is located so you can
solder the balance connector. A drop of thin
cyanoacrylate at both ends of the sleeve will
secure the pack.
With the two sticks side by side, solder a
strap across one end and attach the power lead
to the other. On these, unlike the other A123
cells, the button is positive and the can is
negative. A bit of cyanoacrylate will hold
the two sticks together. Put a shrink sleeve
over the whole pack and you are finished.
The weight comes out to 6.2 ounces,
which is only an ounce heavier than a 3S
2100 Li-Poly pack that it will physically
replace. The new pack is only half the
capacity, but when you consider that you
can charge it in 20 minutes with a Cellpro
unit, your overall flying time is not
significantly compromised.
With $40 invested in the A123 4S 1000
mAh pack, it is approximately half the
price of a 3S 2100 mAh Li-Poly pack. And
you will probably get many more cycles
from it.
Electric Racing on the Horizon? Club 40
races, which I mentioned earlier, are
growing in popularity in this part of
Florida. A couple club members converted
the standard Club 40 racer (The World
Models Sky Raider Mach II ARF),
powered by an O.S. 40LA, to electric
using an AXi 2826/10 motor with a 4S
4200 Li-Poly pack. At 820 watts it turns an
APC 10 x 10 at 10,200 rpm.
While the electric-powered version
could not be flown in competition with the
glow-powered models, a demo flight
against one of the top racers showed it to
be quite competitive—enough so that it
appeared that pilot skill would be the
deciding factor in a real race.
Got CG Blues With Your Model? I
swapped an Aero Technologies Ultimate
300 Blue Hawk for some A123 cells. The
original owner had a problem with the
model when the instructions called for a
CG that was 21/4 inches too far back. It
ended up being a tail-heavy dog.
I found that it took 10 ounces of lead to
bring the CG in. There was no way I
would do that; lead in models is against
my religion. What was I to do?
I found that if I made two two-cell
A123 packs, they would fit nicely under
the cowl as far forward as they could be.
They are difficult to get into and out of the
model without removing the spinner,
propeller, and cowl, so I built them in with
a charge/balancing jack that is accessible
to connect to my Cellpro charger/balancer.
That will give me a 45-minute recharge
capability, and because there is no
recorded incident with A123 cells, I feel
reasonably safe leaving them in the model
as I did flight packs for the past half
century.
First flights confirm that the CG is right
03sig4.QXD 1/25/08 8:14 AM Page 111112 MODEL AVIATION
where it belongs. The Blue Hawk is powered
by an AXi 2808/24 motor and a Graupner 9 x
6 propeller.
Florida Electric Fly-Ins Grow: Electric flyins
are growing at a rapid rate here in Florida.
One in late October at Zephyrhills, hosted by
the Can-Am Flyers Inc., had many fliers and
well more than 100 models. The variety was
awesome, including everything from park
flyers to Giant Scale International Miniature
Aerobatic Club 3-D aircraft.
I love what can be done with Scale models
by tucking a motor in them where you have
no cylinder heads or mufflers with which to
contend. In one of the photos is a beautiful
Monocoupe by John Uhle that hides a Hacker
B50-7XL motor with a 6.7:1 gearbox to swing
an 18 x 8 APC-E propeller.
At the Zephyrhills meet I saw a new
company in the vendor’s area. Millennium
R/C, based in Orlando, Florida, features a line
of kits and ARFs of some neat little (don’t
leave home without one) aerobatic models.
They are offered as laser-cut kits, employing a
lot of carbon fiber, PARFs (Partially Almost
Ready to Flys), and ARFs.
But there is more. Those models are
offered as full-house packages, complete with
a DNC Power 20C 1350 mAh, 11.1-volt Li-
Poly battery; a Himax 2025-4200 brushless
motor; an aluminum gearbox, 10T, and
12T/2.0mm pinion gears; 70-spur gear; three
servos; a Castle Creations Thunderbird-18
ESC; a Deans connector set; and heat-shrink
tubing. I saw some talented pilots fly these
models, and they will do everything you want
in a restricted area.
In another vendor booth I found a great
supplier of Velcro that has become the
fastener of choice in many electric-powered
models. Lu Mahoney, the wife of an active
modeler, has handy items such as ONEWRAP
back-to-back hook-and-loop straps
that are ideal for holding down components
and battery packs.
Along with this is a commercial-grade 87S
hook material that—when attached to the
airframe with slow cyanoacrylate, Cyberbond
medium epoxy, or Goop—will hold
everything in place. Lu offers an installation
kit, which includes a 24 x 2-inch 87S hook, 36
x 2-inch ONE-WRAP, 36 x 1-inch ONEWRAP,
and 36 x 1/2-inch ONE-WRAP.
Bloody Hands and Ugly Planes: I got some
pithy comments from a couple readers, one of
whom was offended by the “blood and gore”
shown in my November column. That
message read, “Isn’t it common knowledge
that if you stick your hand in a rotating
propeller that you will get cut?”
The other in the same thread read:
“Seems everything is an ugly sight in
Red’s write-ups, just check out that bird in
the pix next to the hand. And that’s not the
first ugly plane Red has shown, those
planes just don’t deserve magazine page
attention!”
There were only two negative comments
about the blood-and-gore issue. It was
overwhelmingly known that it was a good
object lesson in safety.
To address the ugly models, much of what
goes into a column of this type is driven by
letters and questions from readers or from
questions on forums regarding electric flight.
One of the more popular questions is how to
modify (the name of your favorite glowpowered
airplane here) for electric. The
simplest answer is to show how someone
modified theirs with good results.
Send in those pictures (with details) of
your electric-flight conversions, and maybe
you too can have an ugly airplane published in
MA.
That’s it for this month. Keep smiling and
maybe the snow will melt soon. Better yet,
take a vacation and visit the Sunshine State,
where flying is at its best this time of the year.
Support your US Postal Service and send
an SASE if you want a personalized answer.
The Battery Clinic is located at 12219 NW 9th
Ln., Newberry FL 32669. But E-mail is faster
and saves a tree. (Oh, sorry, we hate trees;
they eat airplanes. MA
Sources:
Lu Mahoney
[email protected]
Millennium R/C
(407) 208-9745
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