June 2003 97
WHEN WE PURCHASE a new radio system, it normally comes
with a 600 or 700 mAh, four-cell, AA Nickel-Cadmium receiver
battery. This battery is just fine for flying 40- or 60-size models,
but a poor choice for larger models.
Many times I have been asked, “What size receiver battery
pack should I use for my Giant Scale model?” This is a tough
question because there are so many variables involved, such as the
number and type of servos, size and weight of the aircraft, and
type of aircraft.
Don’t fret; there is a fairly accurate way to determine what size
receiver battery you really need without relying on a wild guess.
All you need is a charger and cycler. That’s it!
I suggest that if you are going to fly a Radio Control (RC)
Giant that weighs more than 15 pounds, you consider using a sub-
C cell. Sub-C cells come in different heights and mAh ratings, and
the easiest way to tell you have a sub-C pack is if an individual
cell measures roughly 7⁄8 inch in width. A sub-C cell has a lower
impedance than the smaller A-class or AA-class cells, which
means that it can deliver more current.
Let’s begin! Fully charge your test pack. For this test, let’s say
that we are going to use a 1200 mAh battery pack. You should
slow-charge a Nickel-Cadmium battery by using the 10% rule. If
you are going to charge a four-cell, 4.8-volt, 1200 mAh battery
pack, you should charge it at 120 mAh for 14-16 hours.
Once the pack begins to feel warm, it is fully charged. Put the
pack on a cycler and discharge it at 250-300 mAh. When the pack
is fully discharged, simply record the reading.
It is important to charge and cycle a battery pack because you
need to know its actual capacity. The label on the outside of the
pack stating that it is a 1200 mAh pack is not good enough. The
only way to truly know the capacity and performance of a battery
pack is to cycle it. I hope I have made this point clear!
Now that you have an accurate reading on the capacity of your
pack, it is time to fully charge it again. For the sake of simplicity,
let’s say that our test pack has cycled exactly to 1200 mAh.
Install your freshly charged receiver battery pack in your model
and take a 10-minute flight. During this flight put the aircraft
through all its paces; don’t hold back. At the end of 10 minutes,
Sal Calvagna, 1335 Broadway Ave., Holbrook NY 11741; E-mail: [email protected]
RADIO CONTROL GIANTS
Parsons Products Radio Plug Safety Retainer Clip can be
purchased directly from the dealer.
The Quick Fueler is manufactured by The Flying Scotsman Co. of
Bennington, Vermont.
Bob Severance kneels behind his 24-pound Balsa USA Fly Baby
biplane, which has a G-62 engine.
Ron Marshall’s 80-inch-wingspan 1930s Alexander Bullet. Ron
uses a Saito 100 four-stroke for power.
98 MODEL AVIATION
land the model, remove the battery pack, and place it back onto the
cycler to discharge it.
Here comes the big payoff. If your pack cycles to 1000 mAh,
you have used 200 mAh on your 10-minute flight. With this
information you can safely compute what you would use in a
typical day. If you take four 10-minute flights, you would figure
200 x 4 = 800 mAh. If you take six flights per day, and the typical
flight is 10 minutes, the equation would be 200 x 6 = 1200 mAh.
Since you now know how much capacity is being used by this
particular model, you can determine what size receiver battery to
install. Don’t leave yourself short; make sure you select a battery
pack with a capacity that will more than handle a typical day of
flying. Remember, always use a good voltmeter (with a 200-300
mAh load) to check your voltage after each flight.
Parsons Products of Baton Rouge, Louisiana, produces a Radio
Plug Safety Retainer Clip that is used to keep your battery, servo
extensions, and other connectors tightly coupled. Anytime you
have a high-vibration, high-stress situation, such as those common
in Giant Scale applications, you should use a device such as the
retainer clip to keep the connectors from accidentally pulling apart.
I have seen modelers use all sorts of tape and homemade fixes.
The Parsons retainer clip really does the job and comes specially
made for different radio-system connectors such as Futaba,
Airtronics, JR, Hitec, and others.
I know of one incident where a receiver battery separated from
the switch harness while in a loop because the battery pack became
dislodged. Had a retainer clip been used, that airplane could still be
flying today. You can purchase this product from your local hobby
dealer or directly from Tower Hobbies.
The Flying Scotsman Co. of Bennington, Vermont, manufactures
Wayne Reynolds’ Dynaflite PT-19, which is now a PT-23. Wayne
built the faux radial from scratch.
Ray Lightfoot converted his Hangar 9 PT-19 ARF into a Danish
PT-26. Power is from a Saito 150.
the new Quick Fueler remote fueling
system. The Quick Fueler is easily installed
in the side of your aircraft’s fuselage or
cowling. The plug portion is made to fit
most common fuel tubing.
The Quick Fueler is made from glowand
gas-proof plastic and is lightweight. It
features an easy-grip knob and a friction-fit
O-ring that keeps the plug secured when in
flight. You can install the Quick Fueler two
ways: by teeing into your existing
carburetor line or by using it in a three-line
fuel-tank system.
The Quick Fueler is sold in packages of
two and the price is $4 for the pair. At this
price, how can you not afford to have one
or two? To order your own Quick Fueler
you can call Mark Austin at (802) 447-3509
or E-mail him at [email protected].
You can also write to him at 1101 Murphy
Rd., North Bennington VT 05257.
Bob Severance, San Antonio Prop Buster
Club officer and longtime member of
AMA, is pictured with his 1⁄3-scale Fly
Baby biplane built from a Balsa USA kit.
The model spans 88 inches and is powered
by a Zenoah G-62.
The Fly Baby is covered with Super
Coverite and painted with Behr Premium
Plus Latex paint. To spray the Behr paint, it
was thinned with Flood Floetrol latex paint
conditioner.
The model is a scale representation of
the Pete Bowers home-built of the same
name. Pete Bowers built the Fly Baby in
two versions: a monoplane and a biplane.
Although Balsa USA no longer sells the Fly
Baby biplane kit, I believe the company
still has plans available for it.
Ron Marshall of Phoenix, Arizona, and
member of the One Eighth Air Force, built
a rarely modeled Alexander Bullet—an Al
Mooney design from 1930. The model was
built from enlarged Phillip Kent plans. It is
powered by a Saito 100 four-stroke engine
and spans 80 inches.
Ron covered the Bullet with Koverall
and used Randolph Dope to finish it. The
model sports a homemade, louvered
aluminum cowl, flocked interior, and has a
functioning cabin door.
To secure those huge landing-gear spats,
Ron needed two 7-inch bolts. Since
necessity is the mother of invention, Ron
cut a standard nylon screw in half and used
an arrow-shaft section to make an extended
screw. He glued the top half of the screw
into one end of the approximately 6-inch
arrow shaft and glued the bottom half
(threaded end) into the other end, thereby
creating a 7-inch nylon screw.
Great idea, Ron!
The last two photos are variants of the
ever-popular PT-19 that has been appearing
at Giant Scale International Miniature
Aircraft Association (IMAA) events
everywhere. The PT-23 was built by
Wayne Reynolds of Bath, New York, from
a Dynaflite kit. The model spans 88 inches,
is powered by a Saito 120, and was finished
with Coverite prepainted material. This is
Wayne’s first RC Giant.
The fake radial was built from scratch.
Can you tell which cylinder head is the real
one? Great job, Wayne!
The other photo is of a PT-26 completed
by Ray Lightfoot of Seneca, South
Carolina. This model started life as a
Hangar 9 PT-19 Almost Ready-to-Fly
(ARF) for which Ray adapted an AT-6
canopy from Iron Bay Models.
It is powered by a Saito 150 and sports
Ray’s own shock-absorbing main landing
gear. The model is finished as a Royal
Norwegian Air Force trainer which was
flown at Emsdale airport near Gravenhurst,
Ontario, Canada, during the war. The fullscale
aircraft is in the collection of the
Danish Egeskov Veteran Museum.
Three basic variations of the Fairchild
PT were produced: the PT-19, PT-23, and
PT-26. All three used the same basic
airframe. The first and most common—the
PT-19—is an open-cockpit design and
features Fairchild’s Ranger engine with its
six inverted inline cylinders.
The PT-26 is the Canadian version of
the PT-19 and features a sliding canopy and
a cockpit heating system for protection
against the Canadian winters.
The PT-23 version is identical to the
PT-19 from the firewall back. The
difference between the two aircraft is the
Continental 670 radial engine mounted on
the front of the PT-23. Production of PT-
23s began in 1942 when concerns mounted
over a possible shortage of Ranger engines.
Remember, whether you’re building,
flying, or just thinking about both, keep it
fun! See you next month! MA
June 2003 99
Edition: Model Aviation - 2003/06
Page Numbers: 97,98
Edition: Model Aviation - 2003/06
Page Numbers: 97,98
June 2003 97
WHEN WE PURCHASE a new radio system, it normally comes
with a 600 or 700 mAh, four-cell, AA Nickel-Cadmium receiver
battery. This battery is just fine for flying 40- or 60-size models,
but a poor choice for larger models.
Many times I have been asked, “What size receiver battery
pack should I use for my Giant Scale model?” This is a tough
question because there are so many variables involved, such as the
number and type of servos, size and weight of the aircraft, and
type of aircraft.
Don’t fret; there is a fairly accurate way to determine what size
receiver battery you really need without relying on a wild guess.
All you need is a charger and cycler. That’s it!
I suggest that if you are going to fly a Radio Control (RC)
Giant that weighs more than 15 pounds, you consider using a sub-
C cell. Sub-C cells come in different heights and mAh ratings, and
the easiest way to tell you have a sub-C pack is if an individual
cell measures roughly 7⁄8 inch in width. A sub-C cell has a lower
impedance than the smaller A-class or AA-class cells, which
means that it can deliver more current.
Let’s begin! Fully charge your test pack. For this test, let’s say
that we are going to use a 1200 mAh battery pack. You should
slow-charge a Nickel-Cadmium battery by using the 10% rule. If
you are going to charge a four-cell, 4.8-volt, 1200 mAh battery
pack, you should charge it at 120 mAh for 14-16 hours.
Once the pack begins to feel warm, it is fully charged. Put the
pack on a cycler and discharge it at 250-300 mAh. When the pack
is fully discharged, simply record the reading.
It is important to charge and cycle a battery pack because you
need to know its actual capacity. The label on the outside of the
pack stating that it is a 1200 mAh pack is not good enough. The
only way to truly know the capacity and performance of a battery
pack is to cycle it. I hope I have made this point clear!
Now that you have an accurate reading on the capacity of your
pack, it is time to fully charge it again. For the sake of simplicity,
let’s say that our test pack has cycled exactly to 1200 mAh.
Install your freshly charged receiver battery pack in your model
and take a 10-minute flight. During this flight put the aircraft
through all its paces; don’t hold back. At the end of 10 minutes,
Sal Calvagna, 1335 Broadway Ave., Holbrook NY 11741; E-mail: [email protected]
RADIO CONTROL GIANTS
Parsons Products Radio Plug Safety Retainer Clip can be
purchased directly from the dealer.
The Quick Fueler is manufactured by The Flying Scotsman Co. of
Bennington, Vermont.
Bob Severance kneels behind his 24-pound Balsa USA Fly Baby
biplane, which has a G-62 engine.
Ron Marshall’s 80-inch-wingspan 1930s Alexander Bullet. Ron
uses a Saito 100 four-stroke for power.
98 MODEL AVIATION
land the model, remove the battery pack, and place it back onto the
cycler to discharge it.
Here comes the big payoff. If your pack cycles to 1000 mAh,
you have used 200 mAh on your 10-minute flight. With this
information you can safely compute what you would use in a
typical day. If you take four 10-minute flights, you would figure
200 x 4 = 800 mAh. If you take six flights per day, and the typical
flight is 10 minutes, the equation would be 200 x 6 = 1200 mAh.
Since you now know how much capacity is being used by this
particular model, you can determine what size receiver battery to
install. Don’t leave yourself short; make sure you select a battery
pack with a capacity that will more than handle a typical day of
flying. Remember, always use a good voltmeter (with a 200-300
mAh load) to check your voltage after each flight.
Parsons Products of Baton Rouge, Louisiana, produces a Radio
Plug Safety Retainer Clip that is used to keep your battery, servo
extensions, and other connectors tightly coupled. Anytime you
have a high-vibration, high-stress situation, such as those common
in Giant Scale applications, you should use a device such as the
retainer clip to keep the connectors from accidentally pulling apart.
I have seen modelers use all sorts of tape and homemade fixes.
The Parsons retainer clip really does the job and comes specially
made for different radio-system connectors such as Futaba,
Airtronics, JR, Hitec, and others.
I know of one incident where a receiver battery separated from
the switch harness while in a loop because the battery pack became
dislodged. Had a retainer clip been used, that airplane could still be
flying today. You can purchase this product from your local hobby
dealer or directly from Tower Hobbies.
The Flying Scotsman Co. of Bennington, Vermont, manufactures
Wayne Reynolds’ Dynaflite PT-19, which is now a PT-23. Wayne
built the faux radial from scratch.
Ray Lightfoot converted his Hangar 9 PT-19 ARF into a Danish
PT-26. Power is from a Saito 150.
the new Quick Fueler remote fueling
system. The Quick Fueler is easily installed
in the side of your aircraft’s fuselage or
cowling. The plug portion is made to fit
most common fuel tubing.
The Quick Fueler is made from glowand
gas-proof plastic and is lightweight. It
features an easy-grip knob and a friction-fit
O-ring that keeps the plug secured when in
flight. You can install the Quick Fueler two
ways: by teeing into your existing
carburetor line or by using it in a three-line
fuel-tank system.
The Quick Fueler is sold in packages of
two and the price is $4 for the pair. At this
price, how can you not afford to have one
or two? To order your own Quick Fueler
you can call Mark Austin at (802) 447-3509
or E-mail him at [email protected].
You can also write to him at 1101 Murphy
Rd., North Bennington VT 05257.
Bob Severance, San Antonio Prop Buster
Club officer and longtime member of
AMA, is pictured with his 1⁄3-scale Fly
Baby biplane built from a Balsa USA kit.
The model spans 88 inches and is powered
by a Zenoah G-62.
The Fly Baby is covered with Super
Coverite and painted with Behr Premium
Plus Latex paint. To spray the Behr paint, it
was thinned with Flood Floetrol latex paint
conditioner.
The model is a scale representation of
the Pete Bowers home-built of the same
name. Pete Bowers built the Fly Baby in
two versions: a monoplane and a biplane.
Although Balsa USA no longer sells the Fly
Baby biplane kit, I believe the company
still has plans available for it.
Ron Marshall of Phoenix, Arizona, and
member of the One Eighth Air Force, built
a rarely modeled Alexander Bullet—an Al
Mooney design from 1930. The model was
built from enlarged Phillip Kent plans. It is
powered by a Saito 100 four-stroke engine
and spans 80 inches.
Ron covered the Bullet with Koverall
and used Randolph Dope to finish it. The
model sports a homemade, louvered
aluminum cowl, flocked interior, and has a
functioning cabin door.
To secure those huge landing-gear spats,
Ron needed two 7-inch bolts. Since
necessity is the mother of invention, Ron
cut a standard nylon screw in half and used
an arrow-shaft section to make an extended
screw. He glued the top half of the screw
into one end of the approximately 6-inch
arrow shaft and glued the bottom half
(threaded end) into the other end, thereby
creating a 7-inch nylon screw.
Great idea, Ron!
The last two photos are variants of the
ever-popular PT-19 that has been appearing
at Giant Scale International Miniature
Aircraft Association (IMAA) events
everywhere. The PT-23 was built by
Wayne Reynolds of Bath, New York, from
a Dynaflite kit. The model spans 88 inches,
is powered by a Saito 120, and was finished
with Coverite prepainted material. This is
Wayne’s first RC Giant.
The fake radial was built from scratch.
Can you tell which cylinder head is the real
one? Great job, Wayne!
The other photo is of a PT-26 completed
by Ray Lightfoot of Seneca, South
Carolina. This model started life as a
Hangar 9 PT-19 Almost Ready-to-Fly
(ARF) for which Ray adapted an AT-6
canopy from Iron Bay Models.
It is powered by a Saito 150 and sports
Ray’s own shock-absorbing main landing
gear. The model is finished as a Royal
Norwegian Air Force trainer which was
flown at Emsdale airport near Gravenhurst,
Ontario, Canada, during the war. The fullscale
aircraft is in the collection of the
Danish Egeskov Veteran Museum.
Three basic variations of the Fairchild
PT were produced: the PT-19, PT-23, and
PT-26. All three used the same basic
airframe. The first and most common—the
PT-19—is an open-cockpit design and
features Fairchild’s Ranger engine with its
six inverted inline cylinders.
The PT-26 is the Canadian version of
the PT-19 and features a sliding canopy and
a cockpit heating system for protection
against the Canadian winters.
The PT-23 version is identical to the
PT-19 from the firewall back. The
difference between the two aircraft is the
Continental 670 radial engine mounted on
the front of the PT-23. Production of PT-
23s began in 1942 when concerns mounted
over a possible shortage of Ranger engines.
Remember, whether you’re building,
flying, or just thinking about both, keep it
fun! See you next month! MA
June 2003 99