66 MODEL AVIATION
THIS IS THE seventh monthly column in which I try to give you the
best possible answers to questions you have written in or sent via Email.
I expect to make this introduction only one more time. By now
you should be familiar with the routine.
Each new question is given a sequential number for identification
purposes. Because publication space is limited, part of this column will
be printed here, and the whole thing will be posted on the AMA Web
site at http://modelaircraft.org/mag/FAQ/index.asp. All questions and
answers appear there.
Let’s start!
Q54: “In the process of assembling an ARF model, I discovered that
the slots for the wing-panel center brace had not been provided by the
manufacturer. I was forced to make my own slots, which took a lot of
Bob Aberle
F r e q u e n t l y A s k e d Q u e s t i o n s
E-mail: [email protected]
The wingtip of Hobby Lobby’s electric-powered Bonnie 20 ARF.
Note that the aileron goes all the way out to the tip.
The Bonnie 20’s inside, or root, section contains a slot that has
been precut to accept a heavy-duty plywood brace.
The author adheres .007-inch-thick x 1⁄4-inch-wide carbon-fiber
tape with cyanoacrylate to reinforce a model’s wing TE.
Carbon-fiber tape is cemented in place on the TE. A piece of the
tape is shown below. A source is provided in the text.
extra time. Then later I realized that the ailerons hit or interfered with
the fuselage. Was this aircraft manufactured improperly or did I do
something wrong?”
A54: I corresponded with my reader friend and learned that the aircraft
in question was the popular electric-powered Hobby Lobby Bonnie 20
ARF. I reviewed this model on AMA’s Sport Aviator online magazine.
You can read the article at www.masportaviator.com/ah.asp?CatID=1
&ID=39.
The first thing I learned from the reader is that he started the simple
assembly process before he had read one word
of the provided instructions. The first thing he
did was apply molded-plastic covers at each
wingtip. Then he proceeded to join the two
wing panels using a plywood brace that fits
into a slot cut out in the center-section. His
trouble began when he couldn’t find any slots
for the plywood brace.
Thinking that the manufacturer had
forgotten this step and wanting to get on with
the assembly, he routed out two new slots and
joined and cemented the wing panels. The next
problem was that when he placed the
assembled wing on top of the fuselage, the
ailerons touched the fuselage sides. The
ailerons were restricted in motion because they
interfered with the fuselage.
It didn’t take long to figure out this reader’s
problem. He placed those molded-plastic
wingtips on the center-section. It was easy to
do since the wing panels are rectangular in
shape. These tips quickly covered the slots that
the manufacturer had provided for the
plywood brace. So the tips were the center,
and the center portion was at the tips; both
wing panels had been reversed.
The ailerons were designed to start
approximately 4 inches out from the centerline and then run out to the
tips. With the panels reversed, the ailerons went almost to the
centerline of the fuselage, and that was why they were hitting the
fuselage. The reader also corrected the aileron-clearance problem and
ultimately finished the aircraft.
But the real story here is that the reader did not go through all of
the instructions before starting the assembly process. If he had
attempted to join the wing panels before adding the molded plastic
tips, his error would quickly have been discovered.
You have to say to yourself, If I have to do a great deal of
complicated cutting to an ARF, I must be doing something wrong.
Even an ARF, which requires little assembly time, can be done
improperly if you fail to read the provided instructions.
Q55: “I have noted that the rubber bands used to hold the wing to my
model’s fuselage are beginning to cut into the wing trailing edge
material. Is there an easy way to reinforce this area so that the rubber
bands don’t eventually cut through the trailing edge?”
A55: Years ago we used a folded, thin sheet of aluminum as a TE
November 2004 67
Famous micro-RC modeler Nick Leichty, right, holds one of his tiny RC biplanes that
weighs only a couple of ounces. At left is micro supplier Bob Selman.
RP Products’ Lil’ Trickler will accept up to three RC-system
chargers (shown). It is inexpensive and works as indicated.
The SuperTest PRO allows you to discharge-test Ni-Cd, NiMH, or
Li-Poly batteries up to 14.0 volts and 2.0-amp loads.
reinforcement. The technique worked, but occasionally the aluminum
would act almost like a knife, cutting into the rubber bands.
A better technique was to add a thin piece of plywood to the upper
wing TE at the center-section. This proved to be kind of bulky and
looked poor sitting on top of your covering material, but it did the job.
Modern material technology has produced carbon fiber (like
graphite/epoxy) that is extremely strong, yet very thin. I have been
using a .007-inch-thick (1⁄4-inch-wide) carbon-fiber tape that I
purchased from Aerospace Composite Products (www.acpcomposites.
com/).
I cut a roughly 6-inch length and cement it on the top of the TE
stock (at the wing center-section) using thin cyanoacrylate and
accelerator. The combination of the carbon and the cyanoacrylate
makes an extremely hard surface that no rubber band will penetrate.
Also, at only .007 inch thick, you can easily cover this reinforcement,
which makes for a neat installation.
Q56: “In the July 2004 Model Aviation (page 46), you showed a photo
of a Mr. Nick Leichty with one of his tiny, several-gram RC indoor
models. I was very interested in this concept and the fact that Mr.
Leichty offers custom-built micro RC
systems to fly these tiny models. The only
problem is in your article you didn’t mention
how we could get in contact with Mr.
Leichty.”
A56: My apologies for that omission. Nick
has a complete catalog of his ultra-micro RC
components and accessories. Most are
custom-built or handmade for this
application. Nick resides in Florida. You can
E-mail him at [email protected] or call
him at (941) 377-9808.
September 17-19, Nick and many other
indoor RC specialists participated in the
micro-flyers seminars held during the
popular Northeast Electric Aircraft
Technology Fair in upstate New York in the
town of Downsville. You can obtain more
details about this gathering and seminar at
www.neatfair.org.
Q57: “I recently read about using a 24-hour
appliance timer to operate a power strip, to
which I can plug in a series of RC-system
chargers. The idea is to set the timer to come
on for something like one hour in each 24-
hour period. This effectively provides a
trickle charge on the batteries. Is that a good
idea?
“I also have a question on battery cycling.
I’m on a low budget so I’m not ready to buy
a fancy device to discharge my batteries.
What kind of an inexpensive load can I use
to discharge-test my batteries? How low
should I allow the voltage to go during a test
discharge?”
A57: I’ve heard of that 24-hour timer
technique for many years. The idea is to
leave the chargers on just long enough, in a
24-hour period, to maintain a full charge
level. The trick is knowing exactly how
much time to leave the chargers on. Many
would debate whether it should be one, two,
or three hours in a 24-hour period. I doubt if
any two people could agree to the amount of
the “on” period.
RK Products sells a product called the
Lil’ Trickler (www.liltrickler.com), which
accepts as many as three RC-system
chargers. The Lil’ Trickler controls the time
on for these chargers during a 24-hour period
that will essentially maintain the charge
level. It is much more sophisticated than
using a 24-hour timer.
I’ve never used one of those devices, but I
have heard nothing but good reports from
modeling friends who have used it for years.
It is also relatively inexpensive.
As I have explained many times, I only
trickle-charge my transmitter batteries. I’ve
successfully used the ACE RC Digipulse
Multi-Charger for many years. It has six
adjustable outputs. It will charge for a timed
16-hour period and then revert to a pulsed
trickle-charge level. I’ve had at least three of
my six RC transmitters on this unit for more
than five years, and the batteries are still at
their rated output.
I have so many electric-power battery
packs that it would be impractical to put them
on trickle charge. When the airplane gets
really sluggish in flight or lands much sooner
than expected, I discard the pack. Just flying
with electric power does all the cycling you
could ever want.
You can discharge your own batteries, but
it requires considerable discipline and time on
your part. You can use an old electric motor,
some power resistors from your local
RadioShack, or even some 12-volt automotive
bulbs as a load.
You will have to monitor the voltage and
the current while the load is applied. You must
also time how long it takes the load to take
your battery down to approximately 1.0 volt
per cell for Ni-Cd or NiMH. Li-Poly batteries
should be taken down to 3.0 volts per cell.
If you get bored during your testing, walk
away from the battery, and forget to return,
you could easily destroy the battery. With a
Li-Poly battery, you might even have a fire on
your hands. For these reasons, I tell my
modeling friends to buy a dedicated battery
discharge tester. I like the Peak Electronics
SuperTest PRO, which sells for less than
$100. It can handle up to 14.0 volts (in 0.1-
volt increments) and loads up to 2.0 amps.
When people say they can’t afford this
product, I ask them how many RC systems
they own. Most say three or four. I usually
counter by telling them that the first thing they
should buy after their first RC system is a
battery discharge tester. The other thing they
need, especially as an electric flier, is an
AstroFlight digital volt, ampere, and watt
meter.
That’s a wrap for another column. You must
all be outside enjoying your RC flying,
because the reader mail has fallen way off
now that we are into the summer season
across the country. Send me your questions so
we can keep the interest up and help our
fellow modelers at the same time. MA
Edition: Model Aviation - 2004/11
Page Numbers: 66,67,69
Edition: Model Aviation - 2004/11
Page Numbers: 66,67,69
66 MODEL AVIATION
THIS IS THE seventh monthly column in which I try to give you the
best possible answers to questions you have written in or sent via Email.
I expect to make this introduction only one more time. By now
you should be familiar with the routine.
Each new question is given a sequential number for identification
purposes. Because publication space is limited, part of this column will
be printed here, and the whole thing will be posted on the AMA Web
site at http://modelaircraft.org/mag/FAQ/index.asp. All questions and
answers appear there.
Let’s start!
Q54: “In the process of assembling an ARF model, I discovered that
the slots for the wing-panel center brace had not been provided by the
manufacturer. I was forced to make my own slots, which took a lot of
Bob Aberle
F r e q u e n t l y A s k e d Q u e s t i o n s
E-mail: [email protected]
The wingtip of Hobby Lobby’s electric-powered Bonnie 20 ARF.
Note that the aileron goes all the way out to the tip.
The Bonnie 20’s inside, or root, section contains a slot that has
been precut to accept a heavy-duty plywood brace.
The author adheres .007-inch-thick x 1⁄4-inch-wide carbon-fiber
tape with cyanoacrylate to reinforce a model’s wing TE.
Carbon-fiber tape is cemented in place on the TE. A piece of the
tape is shown below. A source is provided in the text.
extra time. Then later I realized that the ailerons hit or interfered with
the fuselage. Was this aircraft manufactured improperly or did I do
something wrong?”
A54: I corresponded with my reader friend and learned that the aircraft
in question was the popular electric-powered Hobby Lobby Bonnie 20
ARF. I reviewed this model on AMA’s Sport Aviator online magazine.
You can read the article at www.masportaviator.com/ah.asp?CatID=1
&ID=39.
The first thing I learned from the reader is that he started the simple
assembly process before he had read one word
of the provided instructions. The first thing he
did was apply molded-plastic covers at each
wingtip. Then he proceeded to join the two
wing panels using a plywood brace that fits
into a slot cut out in the center-section. His
trouble began when he couldn’t find any slots
for the plywood brace.
Thinking that the manufacturer had
forgotten this step and wanting to get on with
the assembly, he routed out two new slots and
joined and cemented the wing panels. The next
problem was that when he placed the
assembled wing on top of the fuselage, the
ailerons touched the fuselage sides. The
ailerons were restricted in motion because they
interfered with the fuselage.
It didn’t take long to figure out this reader’s
problem. He placed those molded-plastic
wingtips on the center-section. It was easy to
do since the wing panels are rectangular in
shape. These tips quickly covered the slots that
the manufacturer had provided for the
plywood brace. So the tips were the center,
and the center portion was at the tips; both
wing panels had been reversed.
The ailerons were designed to start
approximately 4 inches out from the centerline and then run out to the
tips. With the panels reversed, the ailerons went almost to the
centerline of the fuselage, and that was why they were hitting the
fuselage. The reader also corrected the aileron-clearance problem and
ultimately finished the aircraft.
But the real story here is that the reader did not go through all of
the instructions before starting the assembly process. If he had
attempted to join the wing panels before adding the molded plastic
tips, his error would quickly have been discovered.
You have to say to yourself, If I have to do a great deal of
complicated cutting to an ARF, I must be doing something wrong.
Even an ARF, which requires little assembly time, can be done
improperly if you fail to read the provided instructions.
Q55: “I have noted that the rubber bands used to hold the wing to my
model’s fuselage are beginning to cut into the wing trailing edge
material. Is there an easy way to reinforce this area so that the rubber
bands don’t eventually cut through the trailing edge?”
A55: Years ago we used a folded, thin sheet of aluminum as a TE
November 2004 67
Famous micro-RC modeler Nick Leichty, right, holds one of his tiny RC biplanes that
weighs only a couple of ounces. At left is micro supplier Bob Selman.
RP Products’ Lil’ Trickler will accept up to three RC-system
chargers (shown). It is inexpensive and works as indicated.
The SuperTest PRO allows you to discharge-test Ni-Cd, NiMH, or
Li-Poly batteries up to 14.0 volts and 2.0-amp loads.
reinforcement. The technique worked, but occasionally the aluminum
would act almost like a knife, cutting into the rubber bands.
A better technique was to add a thin piece of plywood to the upper
wing TE at the center-section. This proved to be kind of bulky and
looked poor sitting on top of your covering material, but it did the job.
Modern material technology has produced carbon fiber (like
graphite/epoxy) that is extremely strong, yet very thin. I have been
using a .007-inch-thick (1⁄4-inch-wide) carbon-fiber tape that I
purchased from Aerospace Composite Products (www.acpcomposites.
com/).
I cut a roughly 6-inch length and cement it on the top of the TE
stock (at the wing center-section) using thin cyanoacrylate and
accelerator. The combination of the carbon and the cyanoacrylate
makes an extremely hard surface that no rubber band will penetrate.
Also, at only .007 inch thick, you can easily cover this reinforcement,
which makes for a neat installation.
Q56: “In the July 2004 Model Aviation (page 46), you showed a photo
of a Mr. Nick Leichty with one of his tiny, several-gram RC indoor
models. I was very interested in this concept and the fact that Mr.
Leichty offers custom-built micro RC
systems to fly these tiny models. The only
problem is in your article you didn’t mention
how we could get in contact with Mr.
Leichty.”
A56: My apologies for that omission. Nick
has a complete catalog of his ultra-micro RC
components and accessories. Most are
custom-built or handmade for this
application. Nick resides in Florida. You can
E-mail him at [email protected] or call
him at (941) 377-9808.
September 17-19, Nick and many other
indoor RC specialists participated in the
micro-flyers seminars held during the
popular Northeast Electric Aircraft
Technology Fair in upstate New York in the
town of Downsville. You can obtain more
details about this gathering and seminar at
www.neatfair.org.
Q57: “I recently read about using a 24-hour
appliance timer to operate a power strip, to
which I can plug in a series of RC-system
chargers. The idea is to set the timer to come
on for something like one hour in each 24-
hour period. This effectively provides a
trickle charge on the batteries. Is that a good
idea?
“I also have a question on battery cycling.
I’m on a low budget so I’m not ready to buy
a fancy device to discharge my batteries.
What kind of an inexpensive load can I use
to discharge-test my batteries? How low
should I allow the voltage to go during a test
discharge?”
A57: I’ve heard of that 24-hour timer
technique for many years. The idea is to
leave the chargers on just long enough, in a
24-hour period, to maintain a full charge
level. The trick is knowing exactly how
much time to leave the chargers on. Many
would debate whether it should be one, two,
or three hours in a 24-hour period. I doubt if
any two people could agree to the amount of
the “on” period.
RK Products sells a product called the
Lil’ Trickler (www.liltrickler.com), which
accepts as many as three RC-system
chargers. The Lil’ Trickler controls the time
on for these chargers during a 24-hour period
that will essentially maintain the charge
level. It is much more sophisticated than
using a 24-hour timer.
I’ve never used one of those devices, but I
have heard nothing but good reports from
modeling friends who have used it for years.
It is also relatively inexpensive.
As I have explained many times, I only
trickle-charge my transmitter batteries. I’ve
successfully used the ACE RC Digipulse
Multi-Charger for many years. It has six
adjustable outputs. It will charge for a timed
16-hour period and then revert to a pulsed
trickle-charge level. I’ve had at least three of
my six RC transmitters on this unit for more
than five years, and the batteries are still at
their rated output.
I have so many electric-power battery
packs that it would be impractical to put them
on trickle charge. When the airplane gets
really sluggish in flight or lands much sooner
than expected, I discard the pack. Just flying
with electric power does all the cycling you
could ever want.
You can discharge your own batteries, but
it requires considerable discipline and time on
your part. You can use an old electric motor,
some power resistors from your local
RadioShack, or even some 12-volt automotive
bulbs as a load.
You will have to monitor the voltage and
the current while the load is applied. You must
also time how long it takes the load to take
your battery down to approximately 1.0 volt
per cell for Ni-Cd or NiMH. Li-Poly batteries
should be taken down to 3.0 volts per cell.
If you get bored during your testing, walk
away from the battery, and forget to return,
you could easily destroy the battery. With a
Li-Poly battery, you might even have a fire on
your hands. For these reasons, I tell my
modeling friends to buy a dedicated battery
discharge tester. I like the Peak Electronics
SuperTest PRO, which sells for less than
$100. It can handle up to 14.0 volts (in 0.1-
volt increments) and loads up to 2.0 amps.
When people say they can’t afford this
product, I ask them how many RC systems
they own. Most say three or four. I usually
counter by telling them that the first thing they
should buy after their first RC system is a
battery discharge tester. The other thing they
need, especially as an electric flier, is an
AstroFlight digital volt, ampere, and watt
meter.
That’s a wrap for another column. You must
all be outside enjoying your RC flying,
because the reader mail has fallen way off
now that we are into the summer season
across the country. Send me your questions so
we can keep the interest up and help our
fellow modelers at the same time. MA
Edition: Model Aviation - 2004/11
Page Numbers: 66,67,69
66 MODEL AVIATION
THIS IS THE seventh monthly column in which I try to give you the
best possible answers to questions you have written in or sent via Email.
I expect to make this introduction only one more time. By now
you should be familiar with the routine.
Each new question is given a sequential number for identification
purposes. Because publication space is limited, part of this column will
be printed here, and the whole thing will be posted on the AMA Web
site at http://modelaircraft.org/mag/FAQ/index.asp. All questions and
answers appear there.
Let’s start!
Q54: “In the process of assembling an ARF model, I discovered that
the slots for the wing-panel center brace had not been provided by the
manufacturer. I was forced to make my own slots, which took a lot of
Bob Aberle
F r e q u e n t l y A s k e d Q u e s t i o n s
E-mail: [email protected]
The wingtip of Hobby Lobby’s electric-powered Bonnie 20 ARF.
Note that the aileron goes all the way out to the tip.
The Bonnie 20’s inside, or root, section contains a slot that has
been precut to accept a heavy-duty plywood brace.
The author adheres .007-inch-thick x 1⁄4-inch-wide carbon-fiber
tape with cyanoacrylate to reinforce a model’s wing TE.
Carbon-fiber tape is cemented in place on the TE. A piece of the
tape is shown below. A source is provided in the text.
extra time. Then later I realized that the ailerons hit or interfered with
the fuselage. Was this aircraft manufactured improperly or did I do
something wrong?”
A54: I corresponded with my reader friend and learned that the aircraft
in question was the popular electric-powered Hobby Lobby Bonnie 20
ARF. I reviewed this model on AMA’s Sport Aviator online magazine.
You can read the article at www.masportaviator.com/ah.asp?CatID=1
&ID=39.
The first thing I learned from the reader is that he started the simple
assembly process before he had read one word
of the provided instructions. The first thing he
did was apply molded-plastic covers at each
wingtip. Then he proceeded to join the two
wing panels using a plywood brace that fits
into a slot cut out in the center-section. His
trouble began when he couldn’t find any slots
for the plywood brace.
Thinking that the manufacturer had
forgotten this step and wanting to get on with
the assembly, he routed out two new slots and
joined and cemented the wing panels. The next
problem was that when he placed the
assembled wing on top of the fuselage, the
ailerons touched the fuselage sides. The
ailerons were restricted in motion because they
interfered with the fuselage.
It didn’t take long to figure out this reader’s
problem. He placed those molded-plastic
wingtips on the center-section. It was easy to
do since the wing panels are rectangular in
shape. These tips quickly covered the slots that
the manufacturer had provided for the
plywood brace. So the tips were the center,
and the center portion was at the tips; both
wing panels had been reversed.
The ailerons were designed to start
approximately 4 inches out from the centerline and then run out to the
tips. With the panels reversed, the ailerons went almost to the
centerline of the fuselage, and that was why they were hitting the
fuselage. The reader also corrected the aileron-clearance problem and
ultimately finished the aircraft.
But the real story here is that the reader did not go through all of
the instructions before starting the assembly process. If he had
attempted to join the wing panels before adding the molded plastic
tips, his error would quickly have been discovered.
You have to say to yourself, If I have to do a great deal of
complicated cutting to an ARF, I must be doing something wrong.
Even an ARF, which requires little assembly time, can be done
improperly if you fail to read the provided instructions.
Q55: “I have noted that the rubber bands used to hold the wing to my
model’s fuselage are beginning to cut into the wing trailing edge
material. Is there an easy way to reinforce this area so that the rubber
bands don’t eventually cut through the trailing edge?”
A55: Years ago we used a folded, thin sheet of aluminum as a TE
November 2004 67
Famous micro-RC modeler Nick Leichty, right, holds one of his tiny RC biplanes that
weighs only a couple of ounces. At left is micro supplier Bob Selman.
RP Products’ Lil’ Trickler will accept up to three RC-system
chargers (shown). It is inexpensive and works as indicated.
The SuperTest PRO allows you to discharge-test Ni-Cd, NiMH, or
Li-Poly batteries up to 14.0 volts and 2.0-amp loads.
reinforcement. The technique worked, but occasionally the aluminum
would act almost like a knife, cutting into the rubber bands.
A better technique was to add a thin piece of plywood to the upper
wing TE at the center-section. This proved to be kind of bulky and
looked poor sitting on top of your covering material, but it did the job.
Modern material technology has produced carbon fiber (like
graphite/epoxy) that is extremely strong, yet very thin. I have been
using a .007-inch-thick (1⁄4-inch-wide) carbon-fiber tape that I
purchased from Aerospace Composite Products (www.acpcomposites.
com/).
I cut a roughly 6-inch length and cement it on the top of the TE
stock (at the wing center-section) using thin cyanoacrylate and
accelerator. The combination of the carbon and the cyanoacrylate
makes an extremely hard surface that no rubber band will penetrate.
Also, at only .007 inch thick, you can easily cover this reinforcement,
which makes for a neat installation.
Q56: “In the July 2004 Model Aviation (page 46), you showed a photo
of a Mr. Nick Leichty with one of his tiny, several-gram RC indoor
models. I was very interested in this concept and the fact that Mr.
Leichty offers custom-built micro RC
systems to fly these tiny models. The only
problem is in your article you didn’t mention
how we could get in contact with Mr.
Leichty.”
A56: My apologies for that omission. Nick
has a complete catalog of his ultra-micro RC
components and accessories. Most are
custom-built or handmade for this
application. Nick resides in Florida. You can
E-mail him at [email protected] or call
him at (941) 377-9808.
September 17-19, Nick and many other
indoor RC specialists participated in the
micro-flyers seminars held during the
popular Northeast Electric Aircraft
Technology Fair in upstate New York in the
town of Downsville. You can obtain more
details about this gathering and seminar at
www.neatfair.org.
Q57: “I recently read about using a 24-hour
appliance timer to operate a power strip, to
which I can plug in a series of RC-system
chargers. The idea is to set the timer to come
on for something like one hour in each 24-
hour period. This effectively provides a
trickle charge on the batteries. Is that a good
idea?
“I also have a question on battery cycling.
I’m on a low budget so I’m not ready to buy
a fancy device to discharge my batteries.
What kind of an inexpensive load can I use
to discharge-test my batteries? How low
should I allow the voltage to go during a test
discharge?”
A57: I’ve heard of that 24-hour timer
technique for many years. The idea is to
leave the chargers on just long enough, in a
24-hour period, to maintain a full charge
level. The trick is knowing exactly how
much time to leave the chargers on. Many
would debate whether it should be one, two,
or three hours in a 24-hour period. I doubt if
any two people could agree to the amount of
the “on” period.
RK Products sells a product called the
Lil’ Trickler (www.liltrickler.com), which
accepts as many as three RC-system
chargers. The Lil’ Trickler controls the time
on for these chargers during a 24-hour period
that will essentially maintain the charge
level. It is much more sophisticated than
using a 24-hour timer.
I’ve never used one of those devices, but I
have heard nothing but good reports from
modeling friends who have used it for years.
It is also relatively inexpensive.
As I have explained many times, I only
trickle-charge my transmitter batteries. I’ve
successfully used the ACE RC Digipulse
Multi-Charger for many years. It has six
adjustable outputs. It will charge for a timed
16-hour period and then revert to a pulsed
trickle-charge level. I’ve had at least three of
my six RC transmitters on this unit for more
than five years, and the batteries are still at
their rated output.
I have so many electric-power battery
packs that it would be impractical to put them
on trickle charge. When the airplane gets
really sluggish in flight or lands much sooner
than expected, I discard the pack. Just flying
with electric power does all the cycling you
could ever want.
You can discharge your own batteries, but
it requires considerable discipline and time on
your part. You can use an old electric motor,
some power resistors from your local
RadioShack, or even some 12-volt automotive
bulbs as a load.
You will have to monitor the voltage and
the current while the load is applied. You must
also time how long it takes the load to take
your battery down to approximately 1.0 volt
per cell for Ni-Cd or NiMH. Li-Poly batteries
should be taken down to 3.0 volts per cell.
If you get bored during your testing, walk
away from the battery, and forget to return,
you could easily destroy the battery. With a
Li-Poly battery, you might even have a fire on
your hands. For these reasons, I tell my
modeling friends to buy a dedicated battery
discharge tester. I like the Peak Electronics
SuperTest PRO, which sells for less than
$100. It can handle up to 14.0 volts (in 0.1-
volt increments) and loads up to 2.0 amps.
When people say they can’t afford this
product, I ask them how many RC systems
they own. Most say three or four. I usually
counter by telling them that the first thing they
should buy after their first RC system is a
battery discharge tester. The other thing they
need, especially as an electric flier, is an
AstroFlight digital volt, ampere, and watt
meter.
That’s a wrap for another column. You must
all be outside enjoying your RC flying,
because the reader mail has fallen way off
now that we are into the summer season
across the country. Send me your questions so
we can keep the interest up and help our
fellow modelers at the same time. MA