122 MODEL AVIATION
This new unit comes in three versions. The first features a controller
board that allows for the operation of a single servo to raise and lower
flaps. Second, a controller board permits landing gear to be retracted
and lowered, and the third has a controller
board to cycle flaps and retracts together.
Joe has worked with Will Hubin of Kent,
Ohio, in putting together this new system. Will
designed the controller boards.
The accompanying photos and sketch show
how the various parts of this unit are brought
together. A three-line bellcrank and microswitch are mounted so that
the bellcrank operates the microswitch when the bellcrank is in the
high-engine-speed position.
Care must be taken when mounting the microswitch, so that the
bellcrank’s throttle arm makes good contact with the microswitch arm
for positive operation but does not cause binding or impede the
bellcrank’s smooth operation.
IN THE FEBRUARY 2009 column, I featured a multichannel
electronic control system by Al Cargil of Warwick, Pennsylvania.
It could be used with either electric- or glow-powered models.
The push by many for the use of
electronics for throttle and other flight or
operational features seemed to say that we
no longer needed the standard three-line
control system that has been the mainstay
for Scale, Navy Carrier, and sport-flying for
many years.
Joe Eiben of Essex, Maryland, has provided a new idea, which
is a small electronic unit that puts some real life back into the use
of the standard three-line system. Joe’s system consists of a tiny
electronic unit, a battery supply, a microswitch, and one or two
servos, and it allows you to retain the three-line control for
throttle and to independently operate flaps, landing gear, or other
features, depending on the prototype being modeled.
Also included in this column:
• Terrafugia Transition
The Eiben/Hubin multichannel electronic control system
[[email protected]]
Control Line Scale Bill Boss
Wiring (connection) of parts for the FGM-1 Flaps/Gear operating
system is simple. Note the importance of making the right “ground”
connections on the circuit board. Also shown is an alternate-batterysupply
option. Joe Eiben illustration.
Joe Eiben’s Great Planes P-51’s wing is neatly equipped with the
Model FGM-1 Flaps/Gear operating system. Servos and power
supply are off-the-shelf components.
A standard three-line bellcrank shown in the high-speed throttle
position operates a microswitch to provide input signal (circuit
closure) for the Model FGM-1 circuit board. It’s designed to
sequentially raise and lower landing gear and flaps.
The Terrafugia Transition, a full-scale “roadable” aircraft, lifts off
from a conventional runway. Permission to use this photo was
given by Richard Gersh, VP Business Development, of Terrafugia
Inc., Cranes Ct., Woburn MA 01801.
04sig4.QXD_00MSTRPG.QXD 2/23/10 8:53 AM Page 122
The circuit board, known as the
Flaps/Gear Manager, Model FGM-1, is
wired to the microswitch. The sketch
shows the system hookup for the FGM-1
that is used to cycle the flaps and landing
gear retraction together.
The voltage supply for the system is a
standard 4.8-volt Ni-Cd flight pack; a
controller board designated Flaps/Gear
Manager, Model FGM-1; a gear retraction
servo; a standard servo for flap operation;
and a microswitch to trigger the system
shown.
The sketch also shows the three-pin
connections for the servos and battery
supply, an on/off switch, and a port for
charging the flight pack while in the
model. In addition, there is an alternate
voltage supply using three standard “AA”
flashlight-type cells.
Connecting the three-pin connectors of
the servos and battery pack to the circuit
board requires that close attention be paid.
The ground lead of the servos and battery
supply must be connected to the ground
terminals on the circuit board, to prevent
damage to the circuit board.
The ground on the circuit board
terminals and servo connectors are
marked with a “G” in the sketch. The
black (or brown) lead on the servos and
battery pack is generally the ground lead.
When this configuration is powered
up, both the flaps and landing gear are
lowered. After a 10-second delay, the
program inspects the microswitch for a
closure. If found, the program raises the
flaps smoothly during a four-second
period and then raises the landing gear.
After a nine-second delay, the system
is ready to accept a command from the
microswitch to lower the flaps smoothly,
during the course of four seconds, and
then lower the landing gear. Each closure
of the microswitch thereafter repeats the
cycle.
The single-operation Gear Manager,
Model GM-1, is designed to raise and
lower the landing gear using a retract
servo when triggered by the closure of the
microswitch. When powered up, this
system lowers the landing gear.
After a five-second delay (to prevent
consecutive movements), the program
inspects the microswitch and raises the
landing gear when it detects a closure.
After another five-second delay, the
system is ready to accept a command to
lower the landing gear. Each closure of
the microswitch repeats the cycle.
The single-operation system for flaps,
Model FM-1 is designed to use a standard
servo instead of the 180° gear-retraction
servo.
A photo shows Model FGM-1 neatly
installed in the wing of Joe’s 60-size P-51
Mustang, a Great Planes ARF, for the
operation of flaps and landing gear
retraction. The price of the unit will
probably vary depending on what parts of
the system a modeler might have on hand.
Will is selling circuit board FGM-1
April 2010 123
(flaps and retraction) for $20. The singleoperation
Model GM-1, for flaps or gear
retraction, is $15.
The servos that Joe used are from Tower
Hobbies, and they range in price from $15
to $30, depending on standard or retract
version. The microswitch can be found in
most electronic supply stores, such as
RadioShack, for close to $6 or $7. Joe used
Hobbico mechanical retracts for 40- to 60-
size models, also from Tower Hobbies.
Joe noted that he wanted a simple,
foolproof system similar to the one I have
described for many years. The advent of
electric models and electronic systems
made it possible.
Scale fliers who use the three-line
control system can now add retracting gear
and raise/lower flaps on demand on their
models, and they can enjoy more realistic
flight operations. Repeated touch-and-gos
are a breeze with the system.
The preceding description of the system
operation is set for high throttle operation
of the microswitch, but the microswitch can
be installed so that it is tripped with the
three-line bellcrank in the low-enginespeed
position. Joe used the high-speed
throttle position for triggering the
microswitch, to provide better control of
low speed for landing, taxiing, and possible
engine cutoff.
If a modeler wants operation
independent of throttle position, the
microswitch leads can be connected to the
leadouts/flying lines, with one insulated. A
momentary button switch at the control
handle can activate the cycle.
Direct questions about the system
installation/operation to Joe Eiben. See the
“Sources” list for contact information.
Terrafugia Transition: From time to time
I see an item of interest that is related to
full-scale aviation rather than modeling. In
the April 2009 column I wrote about the
extraordinary P-51 Mustang called “Quick
Silver” that was at the 2008 AirVenture
Oshkosh event in Wisconsin. This aircraft
was constructed through the use of parts
from many Mustangs.
Douglas Dahlke of Oshkosh has sent me
a report on another full-scale project shown
at AirVenture 2008 that might be
interesting to many MA readers. The
vehicle is called “Terrafugia Transition
(TT),” and it’s an airplane-car hybrid that
has the promise of being mass-produced.
Terrafugia of Woburn, Massachusetts, is
developing and producing the TT. It can fly
well and operate as a car that can attain
highway speeds. Its folding wing (which
does so in 30 seconds) allows the TT to be
stored in a regular one-car garage.
This two-seat vehicle has a 27-foot, 6-
inch wingspan; is 80 inches wide with
wings folded; is 6 feet, 9 inches high; is
constructed mostly from carbon fiber; and
is powered with a 100-horsepower Rotax
912S engine that runs on regular unleaded
gasoline. It is said to cruise at 115 mph
and has a 450-mile range.
Flight tests were successfully made on
March 5, 2008, at Plattsburgh, New York.
Since then, the TT has made more than 25
successful flights. According to the
company, it has 50 customers waiting for
delivery sometime in 2010.
You can find considerably more
information, news interviews, and
commentary on the Internet by typing
“Terrafugia Transition” into your search
engine. MA
Sources:
Will Hubin
719 Cuyahoga St.
Kent OH 44240
[email protected]
Joe Eiben
[email protected]
Tower Hobbies
(800) 637-6050
www.towerhobbies.com
Bill Boss
77-06 269th St.
New Hyde Park NY 11040
National Association of Scale
Aeromodelers
www.nasascale.org
Visit the AMA Education
Committee Web site at
www.modelaircraft.org/
education.aspx
04sig4.QXD_00MSTRPG.QXD 2/23/10 8:54 AM Page 123
Edition: Model Aviation - 2010/04
Page Numbers: 122,123
Edition: Model Aviation - 2010/04
Page Numbers: 122,123
122 MODEL AVIATION
This new unit comes in three versions. The first features a controller
board that allows for the operation of a single servo to raise and lower
flaps. Second, a controller board permits landing gear to be retracted
and lowered, and the third has a controller
board to cycle flaps and retracts together.
Joe has worked with Will Hubin of Kent,
Ohio, in putting together this new system. Will
designed the controller boards.
The accompanying photos and sketch show
how the various parts of this unit are brought
together. A three-line bellcrank and microswitch are mounted so that
the bellcrank operates the microswitch when the bellcrank is in the
high-engine-speed position.
Care must be taken when mounting the microswitch, so that the
bellcrank’s throttle arm makes good contact with the microswitch arm
for positive operation but does not cause binding or impede the
bellcrank’s smooth operation.
IN THE FEBRUARY 2009 column, I featured a multichannel
electronic control system by Al Cargil of Warwick, Pennsylvania.
It could be used with either electric- or glow-powered models.
The push by many for the use of
electronics for throttle and other flight or
operational features seemed to say that we
no longer needed the standard three-line
control system that has been the mainstay
for Scale, Navy Carrier, and sport-flying for
many years.
Joe Eiben of Essex, Maryland, has provided a new idea, which
is a small electronic unit that puts some real life back into the use
of the standard three-line system. Joe’s system consists of a tiny
electronic unit, a battery supply, a microswitch, and one or two
servos, and it allows you to retain the three-line control for
throttle and to independently operate flaps, landing gear, or other
features, depending on the prototype being modeled.
Also included in this column:
• Terrafugia Transition
The Eiben/Hubin multichannel electronic control system
[[email protected]]
Control Line Scale Bill Boss
Wiring (connection) of parts for the FGM-1 Flaps/Gear operating
system is simple. Note the importance of making the right “ground”
connections on the circuit board. Also shown is an alternate-batterysupply
option. Joe Eiben illustration.
Joe Eiben’s Great Planes P-51’s wing is neatly equipped with the
Model FGM-1 Flaps/Gear operating system. Servos and power
supply are off-the-shelf components.
A standard three-line bellcrank shown in the high-speed throttle
position operates a microswitch to provide input signal (circuit
closure) for the Model FGM-1 circuit board. It’s designed to
sequentially raise and lower landing gear and flaps.
The Terrafugia Transition, a full-scale “roadable” aircraft, lifts off
from a conventional runway. Permission to use this photo was
given by Richard Gersh, VP Business Development, of Terrafugia
Inc., Cranes Ct., Woburn MA 01801.
04sig4.QXD_00MSTRPG.QXD 2/23/10 8:53 AM Page 122
The circuit board, known as the
Flaps/Gear Manager, Model FGM-1, is
wired to the microswitch. The sketch
shows the system hookup for the FGM-1
that is used to cycle the flaps and landing
gear retraction together.
The voltage supply for the system is a
standard 4.8-volt Ni-Cd flight pack; a
controller board designated Flaps/Gear
Manager, Model FGM-1; a gear retraction
servo; a standard servo for flap operation;
and a microswitch to trigger the system
shown.
The sketch also shows the three-pin
connections for the servos and battery
supply, an on/off switch, and a port for
charging the flight pack while in the
model. In addition, there is an alternate
voltage supply using three standard “AA”
flashlight-type cells.
Connecting the three-pin connectors of
the servos and battery pack to the circuit
board requires that close attention be paid.
The ground lead of the servos and battery
supply must be connected to the ground
terminals on the circuit board, to prevent
damage to the circuit board.
The ground on the circuit board
terminals and servo connectors are
marked with a “G” in the sketch. The
black (or brown) lead on the servos and
battery pack is generally the ground lead.
When this configuration is powered
up, both the flaps and landing gear are
lowered. After a 10-second delay, the
program inspects the microswitch for a
closure. If found, the program raises the
flaps smoothly during a four-second
period and then raises the landing gear.
After a nine-second delay, the system
is ready to accept a command from the
microswitch to lower the flaps smoothly,
during the course of four seconds, and
then lower the landing gear. Each closure
of the microswitch thereafter repeats the
cycle.
The single-operation Gear Manager,
Model GM-1, is designed to raise and
lower the landing gear using a retract
servo when triggered by the closure of the
microswitch. When powered up, this
system lowers the landing gear.
After a five-second delay (to prevent
consecutive movements), the program
inspects the microswitch and raises the
landing gear when it detects a closure.
After another five-second delay, the
system is ready to accept a command to
lower the landing gear. Each closure of
the microswitch repeats the cycle.
The single-operation system for flaps,
Model FM-1 is designed to use a standard
servo instead of the 180° gear-retraction
servo.
A photo shows Model FGM-1 neatly
installed in the wing of Joe’s 60-size P-51
Mustang, a Great Planes ARF, for the
operation of flaps and landing gear
retraction. The price of the unit will
probably vary depending on what parts of
the system a modeler might have on hand.
Will is selling circuit board FGM-1
April 2010 123
(flaps and retraction) for $20. The singleoperation
Model GM-1, for flaps or gear
retraction, is $15.
The servos that Joe used are from Tower
Hobbies, and they range in price from $15
to $30, depending on standard or retract
version. The microswitch can be found in
most electronic supply stores, such as
RadioShack, for close to $6 or $7. Joe used
Hobbico mechanical retracts for 40- to 60-
size models, also from Tower Hobbies.
Joe noted that he wanted a simple,
foolproof system similar to the one I have
described for many years. The advent of
electric models and electronic systems
made it possible.
Scale fliers who use the three-line
control system can now add retracting gear
and raise/lower flaps on demand on their
models, and they can enjoy more realistic
flight operations. Repeated touch-and-gos
are a breeze with the system.
The preceding description of the system
operation is set for high throttle operation
of the microswitch, but the microswitch can
be installed so that it is tripped with the
three-line bellcrank in the low-enginespeed
position. Joe used the high-speed
throttle position for triggering the
microswitch, to provide better control of
low speed for landing, taxiing, and possible
engine cutoff.
If a modeler wants operation
independent of throttle position, the
microswitch leads can be connected to the
leadouts/flying lines, with one insulated. A
momentary button switch at the control
handle can activate the cycle.
Direct questions about the system
installation/operation to Joe Eiben. See the
“Sources” list for contact information.
Terrafugia Transition: From time to time
I see an item of interest that is related to
full-scale aviation rather than modeling. In
the April 2009 column I wrote about the
extraordinary P-51 Mustang called “Quick
Silver” that was at the 2008 AirVenture
Oshkosh event in Wisconsin. This aircraft
was constructed through the use of parts
from many Mustangs.
Douglas Dahlke of Oshkosh has sent me
a report on another full-scale project shown
at AirVenture 2008 that might be
interesting to many MA readers. The
vehicle is called “Terrafugia Transition
(TT),” and it’s an airplane-car hybrid that
has the promise of being mass-produced.
Terrafugia of Woburn, Massachusetts, is
developing and producing the TT. It can fly
well and operate as a car that can attain
highway speeds. Its folding wing (which
does so in 30 seconds) allows the TT to be
stored in a regular one-car garage.
This two-seat vehicle has a 27-foot, 6-
inch wingspan; is 80 inches wide with
wings folded; is 6 feet, 9 inches high; is
constructed mostly from carbon fiber; and
is powered with a 100-horsepower Rotax
912S engine that runs on regular unleaded
gasoline. It is said to cruise at 115 mph
and has a 450-mile range.
Flight tests were successfully made on
March 5, 2008, at Plattsburgh, New York.
Since then, the TT has made more than 25
successful flights. According to the
company, it has 50 customers waiting for
delivery sometime in 2010.
You can find considerably more
information, news interviews, and
commentary on the Internet by typing
“Terrafugia Transition” into your search
engine. MA
Sources:
Will Hubin
719 Cuyahoga St.
Kent OH 44240
[email protected]
Joe Eiben
[email protected]
Tower Hobbies
(800) 637-6050
www.towerhobbies.com
Bill Boss
77-06 269th St.
New Hyde Park NY 11040
National Association of Scale
Aeromodelers
www.nasascale.org
Visit the AMA Education
Committee Web site at
www.modelaircraft.org/
education.aspx
04sig4.QXD_00MSTRPG.QXD 2/23/10 8:54 AM Page 123
