72 MODEL AVIATION
An amazing five-channel microreceiver
Micro-Flying John Worth | [email protected]
Also included in this column:
• The MicroBug
• Micro-size toolbox
• A new crop of RTFs
Above: The Micro Invent Minor receiver’s
small size is obvious when compared to a
Pencell battery.
Left: The author’s MicroBug weighs less
than 1 ounce but has rudder, elevator, and
motor controls.
Below: This neat, compact aluminum
toolbox holds a transmitter, micro-flight
supplies, and accessories.
IN THE WORLD of micro-flight RC
components are getting smaller and lighter.
When they are capable of doing more than
many of their larger and heavier
counterparts, that draws attention and that’s
how it is with the Micro Invent Minor
receiver. Made in Slovakia, it is sold in the
United States by Air Midi Micros in
Colorado and Bob Selman Designs in
Missouri.
The Micro Invent Minor is a fivechannel,
crystal-controlled receiver that is
available in three frequency ranges: 35, 40,
and 72 MHz. It can be used with servos and
magnetic actuators. That doesn’t mean it can
operate one or the other.
In addition to motor control, it can
operate four servos, two magnetic actuators,
or two servos and one magnetic actuator
merely by the way the items plug into a
clever arrangement of connector pins on the
receiver. It controls the motor through a
built-in ESC or the ESC circuit can power
an external ESC.
Although it is capable of operating as
many as five channels (motor speed and four
control devices), the Minor is so small that it
is suitable for the smallest and lightest
models for rudder and motor control. It is
11sig3.QXD 9/21/07 11:55 AM Page 72
November 2007 73
Plantraco’s all-foam RTF profile scale Zero with rudder and motor speed control
spans 10 inches and weighs only 4 grams!
The 15-inch-wingspan ParkZone Cessna uses the smallest and lightest-weight spread
spectrum technology available. It is a bargain at roughly $150.
only 3/8 x 5/8 inch and weighs less than 1
gram without the crystal.
The receiver has a range of at least 300
feet and operates on a single Li-Poly cell. Its
basic current consumption is only 6
milliamps. The battery is a high-draincapable,
130 mAh cell produced by The
Atomic Workshops in England.
An earlier edition of the Minor receiver
operated with negative-shift transmitters and
could operate motors with as much as 1 amp
current drain (1.6 amp peak). The newer
edition called the Plus looks identical to the
previous version. It works with either
positive- or negative-shift transmitters and
will handle motors with up to 2 amps of
current (2.6 amps peak).
The Minor is even better now that it can
fly larger, heavier models, yet it is still fine
for the smallest and lightest ones. Either
version of the receiver comes with vertical
or horizontal connector pins.
The MicroBug Model: I have the verticalpin
Micro Invent Minor Plus receiver
installed in a Jack Dobbins-designed
MicroBug. It has a 10.5-inch wingspan and
weighs 22 grams. Its wing area is roughly
50 square inches.
The MicroBug has a GB04 6mm motor
with a 5.8:1 gear reduction that powers a 4-
inch Plantraco propeller. In addition to the
built-in ESC, the receiver operates two
Micro Invent MCA2 magnetic actuators for
rudder and elevator control. These tiny,
cube-shaped actuators are approximately 3/8
inch and weigh 3/4 gram.
The current drain for the actuators is
only 42 milliamps. They have ample power
and smooth proportional-control movement.
Microconnectors plug directly into the
receiver. Suitable for models weighing as
much as 30 grams, the actuators are $22
each. A single 130 mAh, high-discharge
battery sold by The Atomic Workshops of
England provides power.
The MicroBug is a delightful little flyer
that is intended mainly for indoors but is
suitable for outdoor flying in mild breezes.
Construction is light but robust because of
the carbon rod used in the wing structure and
the fuselage tailboom. The tail assembly is
all-balsa 1/32 sheet.
The receiver, Li-Poly battery, and geared
motor are mounted on a 1/2 x 13/4 x 1/16
plywood pylon. Brass push-pull rods connect
the tail control surfaces to the magnetic
actuator control arms. A 1/16 plywood stub
hangs from the fuselage stick, providing a
grip for hand launching.
Micro-Size Toolbox: In keeping with the
idea that micro-flight models are compact and
easy to carry, it is appropriate to use a
smaller-than-typical-size toolbox for carrying
model supplies and equipment.
I found a nice case at a local Wal-Mart
that is 12 inches long, 81/2 inches wide, and
91/2 inches deep. It opens to provide four 31/2
x 10 x 11/4-inch trays and a lower interior
measuring 11 x 8 x 4 inches—just right for
my regular Futaba transmitter to lay inside on
a pad of foam rubber.
The all-aluminum case features lockable
snap latches and a handle. It is actually a
cosmetic organizer with the trade name
Caboodles, and it was less than $24.
The trays are a nice size for carrying an
assortment of tools and supplies. The wellmade
case should last for many years. It could
even serve as a camera case for someone who
carries a number of photo accessories or as a
beverage or lunch box!
A New Era for RTFs: For approximately two
years the micro-flight world has been
inundated with a flood of toy-market RTF RC
models. Most are low-priced, some are good
fliers, and many become a source of
components for home-built micro models.
This market has introduced many newcomers
to RC, and their experiences have generally
been more positive than negative.
A couple newer products from regular
model suppliers have had a dramatic impact
on micro-flight activity this year. Although
some might still regard these new models as
“toys,” they are a whole class of quality and
performance above those that are typically
sold in toy stores.
The first of the newer products was shown
at last April’s R/C Expo in Toledo, Ohio. The
11sig3.QXD 9/21/07 11:44 AM Page 73
other was introduced in July on the RC Micro
World Web site. Both became available to
customers in August.
Horizon Hobby’s ParkZone and Plantraco
of Canada provided samples for me to
evaluate. Plantraco’s arrived first, in the form
of a profile scale model of the World War II
Japanese Zero fighter. It was followed almost
immediately by ParkZone’s scale Cessna 210
Citation.
Both are of excellent design,
craftsmanship, and performance. Each was
ready to fly right out of the box upon
installation of transmitter batteries and
charging of the airborne Li-Poly battery.
From the first hand launch both flew well and
were able to cope with gentle outdoor breezes
although they are basically indoor models
intended for flying in a basketball court-size
gymnasium.
The Zero weighs 4 grams, has a 10-inch
wingspan, and features rudder and motor
speed control. The Cessna is larger—though
still small—with a 15-inch wingspan. It
weighs 18 grams and has motor, rudder, and
elevator control.
The Cessna uses linear servos for the tail
controls and the Zero has a magnetic actuator
at its rudder. The Cessna has a tricycle
landing gear for takeoffs and landings; the
Zero is made for hand launching and landing
on its belly.
The two models look good and are well
scaled and colored authentically. Largely
because they are so light, both have proven to
be crash resistant. After a dozen or so flights
each, the two aircraft still looked like new
when I wrote this article. Each controlled
well, and flying them was comparable to
flying larger and heavier conventional homebuilt
aircraft.
Modeler and public reaction to both
products has been positive. The Zero receives
many favorable comments because its
purchase price is roughly $88 without the
transmitter—a savings appreciated by those
who already have a Plantraco 900 NHz
transmitter from a previous model.
Although it is more expensive, the Cessna
package is applauded because it uses 2.4 GHz
spread spectrum technology. It includes the
smallest and lightest yet spread spectrum
system, and the Cessna’s price of roughly
$150 is a bargain. Being able to fly without
concern for those flying on other RC
frequencies is a plus, and having that
capability in a micro-flight model is
tremendously impressive.
Micro flight is on the cutting edge of new
technology. It is rapidly outgrowing the
image held by some that smaller and lighter is
somehow inferior, and it is becoming a
significant category of modeling. As evidence
of this, nearly 1,000 people from more than
30 countries subscribe to the online monthly
micro-flight resource called RC Micro World.
The AMA Web site has good micro-flight
information and MA Sport Aviator offers a
number of micro-flight articles including “A
Free Guide to Indoor RC Flying,” with many
photos and details. MA
Sources:
Air Midi Micros
(775) 783-8545
www.airmidimicros.com
Bob Selman Designs
(417) 358-9521
www.bsdmicrorc.com
RC Micro World
www.cloud9rc.com
AMA
www.modelaircraft.org
MA Sport Aviator
www.masportaviator.com
Edition: Model Aviation - 2007/11
Page Numbers: 72,73,74
Edition: Model Aviation - 2007/11
Page Numbers: 72,73,74
72 MODEL AVIATION
An amazing five-channel microreceiver
Micro-Flying John Worth | [email protected]
Also included in this column:
• The MicroBug
• Micro-size toolbox
• A new crop of RTFs
Above: The Micro Invent Minor receiver’s
small size is obvious when compared to a
Pencell battery.
Left: The author’s MicroBug weighs less
than 1 ounce but has rudder, elevator, and
motor controls.
Below: This neat, compact aluminum
toolbox holds a transmitter, micro-flight
supplies, and accessories.
IN THE WORLD of micro-flight RC
components are getting smaller and lighter.
When they are capable of doing more than
many of their larger and heavier
counterparts, that draws attention and that’s
how it is with the Micro Invent Minor
receiver. Made in Slovakia, it is sold in the
United States by Air Midi Micros in
Colorado and Bob Selman Designs in
Missouri.
The Micro Invent Minor is a fivechannel,
crystal-controlled receiver that is
available in three frequency ranges: 35, 40,
and 72 MHz. It can be used with servos and
magnetic actuators. That doesn’t mean it can
operate one or the other.
In addition to motor control, it can
operate four servos, two magnetic actuators,
or two servos and one magnetic actuator
merely by the way the items plug into a
clever arrangement of connector pins on the
receiver. It controls the motor through a
built-in ESC or the ESC circuit can power
an external ESC.
Although it is capable of operating as
many as five channels (motor speed and four
control devices), the Minor is so small that it
is suitable for the smallest and lightest
models for rudder and motor control. It is
11sig3.QXD 9/21/07 11:55 AM Page 72
November 2007 73
Plantraco’s all-foam RTF profile scale Zero with rudder and motor speed control
spans 10 inches and weighs only 4 grams!
The 15-inch-wingspan ParkZone Cessna uses the smallest and lightest-weight spread
spectrum technology available. It is a bargain at roughly $150.
only 3/8 x 5/8 inch and weighs less than 1
gram without the crystal.
The receiver has a range of at least 300
feet and operates on a single Li-Poly cell. Its
basic current consumption is only 6
milliamps. The battery is a high-draincapable,
130 mAh cell produced by The
Atomic Workshops in England.
An earlier edition of the Minor receiver
operated with negative-shift transmitters and
could operate motors with as much as 1 amp
current drain (1.6 amp peak). The newer
edition called the Plus looks identical to the
previous version. It works with either
positive- or negative-shift transmitters and
will handle motors with up to 2 amps of
current (2.6 amps peak).
The Minor is even better now that it can
fly larger, heavier models, yet it is still fine
for the smallest and lightest ones. Either
version of the receiver comes with vertical
or horizontal connector pins.
The MicroBug Model: I have the verticalpin
Micro Invent Minor Plus receiver
installed in a Jack Dobbins-designed
MicroBug. It has a 10.5-inch wingspan and
weighs 22 grams. Its wing area is roughly
50 square inches.
The MicroBug has a GB04 6mm motor
with a 5.8:1 gear reduction that powers a 4-
inch Plantraco propeller. In addition to the
built-in ESC, the receiver operates two
Micro Invent MCA2 magnetic actuators for
rudder and elevator control. These tiny,
cube-shaped actuators are approximately 3/8
inch and weigh 3/4 gram.
The current drain for the actuators is
only 42 milliamps. They have ample power
and smooth proportional-control movement.
Microconnectors plug directly into the
receiver. Suitable for models weighing as
much as 30 grams, the actuators are $22
each. A single 130 mAh, high-discharge
battery sold by The Atomic Workshops of
England provides power.
The MicroBug is a delightful little flyer
that is intended mainly for indoors but is
suitable for outdoor flying in mild breezes.
Construction is light but robust because of
the carbon rod used in the wing structure and
the fuselage tailboom. The tail assembly is
all-balsa 1/32 sheet.
The receiver, Li-Poly battery, and geared
motor are mounted on a 1/2 x 13/4 x 1/16
plywood pylon. Brass push-pull rods connect
the tail control surfaces to the magnetic
actuator control arms. A 1/16 plywood stub
hangs from the fuselage stick, providing a
grip for hand launching.
Micro-Size Toolbox: In keeping with the
idea that micro-flight models are compact and
easy to carry, it is appropriate to use a
smaller-than-typical-size toolbox for carrying
model supplies and equipment.
I found a nice case at a local Wal-Mart
that is 12 inches long, 81/2 inches wide, and
91/2 inches deep. It opens to provide four 31/2
x 10 x 11/4-inch trays and a lower interior
measuring 11 x 8 x 4 inches—just right for
my regular Futaba transmitter to lay inside on
a pad of foam rubber.
The all-aluminum case features lockable
snap latches and a handle. It is actually a
cosmetic organizer with the trade name
Caboodles, and it was less than $24.
The trays are a nice size for carrying an
assortment of tools and supplies. The wellmade
case should last for many years. It could
even serve as a camera case for someone who
carries a number of photo accessories or as a
beverage or lunch box!
A New Era for RTFs: For approximately two
years the micro-flight world has been
inundated with a flood of toy-market RTF RC
models. Most are low-priced, some are good
fliers, and many become a source of
components for home-built micro models.
This market has introduced many newcomers
to RC, and their experiences have generally
been more positive than negative.
A couple newer products from regular
model suppliers have had a dramatic impact
on micro-flight activity this year. Although
some might still regard these new models as
“toys,” they are a whole class of quality and
performance above those that are typically
sold in toy stores.
The first of the newer products was shown
at last April’s R/C Expo in Toledo, Ohio. The
11sig3.QXD 9/21/07 11:44 AM Page 73
other was introduced in July on the RC Micro
World Web site. Both became available to
customers in August.
Horizon Hobby’s ParkZone and Plantraco
of Canada provided samples for me to
evaluate. Plantraco’s arrived first, in the form
of a profile scale model of the World War II
Japanese Zero fighter. It was followed almost
immediately by ParkZone’s scale Cessna 210
Citation.
Both are of excellent design,
craftsmanship, and performance. Each was
ready to fly right out of the box upon
installation of transmitter batteries and
charging of the airborne Li-Poly battery.
From the first hand launch both flew well and
were able to cope with gentle outdoor breezes
although they are basically indoor models
intended for flying in a basketball court-size
gymnasium.
The Zero weighs 4 grams, has a 10-inch
wingspan, and features rudder and motor
speed control. The Cessna is larger—though
still small—with a 15-inch wingspan. It
weighs 18 grams and has motor, rudder, and
elevator control.
The Cessna uses linear servos for the tail
controls and the Zero has a magnetic actuator
at its rudder. The Cessna has a tricycle
landing gear for takeoffs and landings; the
Zero is made for hand launching and landing
on its belly.
The two models look good and are well
scaled and colored authentically. Largely
because they are so light, both have proven to
be crash resistant. After a dozen or so flights
each, the two aircraft still looked like new
when I wrote this article. Each controlled
well, and flying them was comparable to
flying larger and heavier conventional homebuilt
aircraft.
Modeler and public reaction to both
products has been positive. The Zero receives
many favorable comments because its
purchase price is roughly $88 without the
transmitter—a savings appreciated by those
who already have a Plantraco 900 NHz
transmitter from a previous model.
Although it is more expensive, the Cessna
package is applauded because it uses 2.4 GHz
spread spectrum technology. It includes the
smallest and lightest yet spread spectrum
system, and the Cessna’s price of roughly
$150 is a bargain. Being able to fly without
concern for those flying on other RC
frequencies is a plus, and having that
capability in a micro-flight model is
tremendously impressive.
Micro flight is on the cutting edge of new
technology. It is rapidly outgrowing the
image held by some that smaller and lighter is
somehow inferior, and it is becoming a
significant category of modeling. As evidence
of this, nearly 1,000 people from more than
30 countries subscribe to the online monthly
micro-flight resource called RC Micro World.
The AMA Web site has good micro-flight
information and MA Sport Aviator offers a
number of micro-flight articles including “A
Free Guide to Indoor RC Flying,” with many
photos and details. MA
Sources:
Air Midi Micros
(775) 783-8545
www.airmidimicros.com
Bob Selman Designs
(417) 358-9521
www.bsdmicrorc.com
RC Micro World
www.cloud9rc.com
AMA
www.modelaircraft.org
MA Sport Aviator
www.masportaviator.com
Edition: Model Aviation - 2007/11
Page Numbers: 72,73,74
72 MODEL AVIATION
An amazing five-channel microreceiver
Micro-Flying John Worth | [email protected]
Also included in this column:
• The MicroBug
• Micro-size toolbox
• A new crop of RTFs
Above: The Micro Invent Minor receiver’s
small size is obvious when compared to a
Pencell battery.
Left: The author’s MicroBug weighs less
than 1 ounce but has rudder, elevator, and
motor controls.
Below: This neat, compact aluminum
toolbox holds a transmitter, micro-flight
supplies, and accessories.
IN THE WORLD of micro-flight RC
components are getting smaller and lighter.
When they are capable of doing more than
many of their larger and heavier
counterparts, that draws attention and that’s
how it is with the Micro Invent Minor
receiver. Made in Slovakia, it is sold in the
United States by Air Midi Micros in
Colorado and Bob Selman Designs in
Missouri.
The Micro Invent Minor is a fivechannel,
crystal-controlled receiver that is
available in three frequency ranges: 35, 40,
and 72 MHz. It can be used with servos and
magnetic actuators. That doesn’t mean it can
operate one or the other.
In addition to motor control, it can
operate four servos, two magnetic actuators,
or two servos and one magnetic actuator
merely by the way the items plug into a
clever arrangement of connector pins on the
receiver. It controls the motor through a
built-in ESC or the ESC circuit can power
an external ESC.
Although it is capable of operating as
many as five channels (motor speed and four
control devices), the Minor is so small that it
is suitable for the smallest and lightest
models for rudder and motor control. It is
11sig3.QXD 9/21/07 11:55 AM Page 72
November 2007 73
Plantraco’s all-foam RTF profile scale Zero with rudder and motor speed control
spans 10 inches and weighs only 4 grams!
The 15-inch-wingspan ParkZone Cessna uses the smallest and lightest-weight spread
spectrum technology available. It is a bargain at roughly $150.
only 3/8 x 5/8 inch and weighs less than 1
gram without the crystal.
The receiver has a range of at least 300
feet and operates on a single Li-Poly cell. Its
basic current consumption is only 6
milliamps. The battery is a high-draincapable,
130 mAh cell produced by The
Atomic Workshops in England.
An earlier edition of the Minor receiver
operated with negative-shift transmitters and
could operate motors with as much as 1 amp
current drain (1.6 amp peak). The newer
edition called the Plus looks identical to the
previous version. It works with either
positive- or negative-shift transmitters and
will handle motors with up to 2 amps of
current (2.6 amps peak).
The Minor is even better now that it can
fly larger, heavier models, yet it is still fine
for the smallest and lightest ones. Either
version of the receiver comes with vertical
or horizontal connector pins.
The MicroBug Model: I have the verticalpin
Micro Invent Minor Plus receiver
installed in a Jack Dobbins-designed
MicroBug. It has a 10.5-inch wingspan and
weighs 22 grams. Its wing area is roughly
50 square inches.
The MicroBug has a GB04 6mm motor
with a 5.8:1 gear reduction that powers a 4-
inch Plantraco propeller. In addition to the
built-in ESC, the receiver operates two
Micro Invent MCA2 magnetic actuators for
rudder and elevator control. These tiny,
cube-shaped actuators are approximately 3/8
inch and weigh 3/4 gram.
The current drain for the actuators is
only 42 milliamps. They have ample power
and smooth proportional-control movement.
Microconnectors plug directly into the
receiver. Suitable for models weighing as
much as 30 grams, the actuators are $22
each. A single 130 mAh, high-discharge
battery sold by The Atomic Workshops of
England provides power.
The MicroBug is a delightful little flyer
that is intended mainly for indoors but is
suitable for outdoor flying in mild breezes.
Construction is light but robust because of
the carbon rod used in the wing structure and
the fuselage tailboom. The tail assembly is
all-balsa 1/32 sheet.
The receiver, Li-Poly battery, and geared
motor are mounted on a 1/2 x 13/4 x 1/16
plywood pylon. Brass push-pull rods connect
the tail control surfaces to the magnetic
actuator control arms. A 1/16 plywood stub
hangs from the fuselage stick, providing a
grip for hand launching.
Micro-Size Toolbox: In keeping with the
idea that micro-flight models are compact and
easy to carry, it is appropriate to use a
smaller-than-typical-size toolbox for carrying
model supplies and equipment.
I found a nice case at a local Wal-Mart
that is 12 inches long, 81/2 inches wide, and
91/2 inches deep. It opens to provide four 31/2
x 10 x 11/4-inch trays and a lower interior
measuring 11 x 8 x 4 inches—just right for
my regular Futaba transmitter to lay inside on
a pad of foam rubber.
The all-aluminum case features lockable
snap latches and a handle. It is actually a
cosmetic organizer with the trade name
Caboodles, and it was less than $24.
The trays are a nice size for carrying an
assortment of tools and supplies. The wellmade
case should last for many years. It could
even serve as a camera case for someone who
carries a number of photo accessories or as a
beverage or lunch box!
A New Era for RTFs: For approximately two
years the micro-flight world has been
inundated with a flood of toy-market RTF RC
models. Most are low-priced, some are good
fliers, and many become a source of
components for home-built micro models.
This market has introduced many newcomers
to RC, and their experiences have generally
been more positive than negative.
A couple newer products from regular
model suppliers have had a dramatic impact
on micro-flight activity this year. Although
some might still regard these new models as
“toys,” they are a whole class of quality and
performance above those that are typically
sold in toy stores.
The first of the newer products was shown
at last April’s R/C Expo in Toledo, Ohio. The
11sig3.QXD 9/21/07 11:44 AM Page 73
other was introduced in July on the RC Micro
World Web site. Both became available to
customers in August.
Horizon Hobby’s ParkZone and Plantraco
of Canada provided samples for me to
evaluate. Plantraco’s arrived first, in the form
of a profile scale model of the World War II
Japanese Zero fighter. It was followed almost
immediately by ParkZone’s scale Cessna 210
Citation.
Both are of excellent design,
craftsmanship, and performance. Each was
ready to fly right out of the box upon
installation of transmitter batteries and
charging of the airborne Li-Poly battery.
From the first hand launch both flew well and
were able to cope with gentle outdoor breezes
although they are basically indoor models
intended for flying in a basketball court-size
gymnasium.
The Zero weighs 4 grams, has a 10-inch
wingspan, and features rudder and motor
speed control. The Cessna is larger—though
still small—with a 15-inch wingspan. It
weighs 18 grams and has motor, rudder, and
elevator control.
The Cessna uses linear servos for the tail
controls and the Zero has a magnetic actuator
at its rudder. The Cessna has a tricycle
landing gear for takeoffs and landings; the
Zero is made for hand launching and landing
on its belly.
The two models look good and are well
scaled and colored authentically. Largely
because they are so light, both have proven to
be crash resistant. After a dozen or so flights
each, the two aircraft still looked like new
when I wrote this article. Each controlled
well, and flying them was comparable to
flying larger and heavier conventional homebuilt
aircraft.
Modeler and public reaction to both
products has been positive. The Zero receives
many favorable comments because its
purchase price is roughly $88 without the
transmitter—a savings appreciated by those
who already have a Plantraco 900 NHz
transmitter from a previous model.
Although it is more expensive, the Cessna
package is applauded because it uses 2.4 GHz
spread spectrum technology. It includes the
smallest and lightest yet spread spectrum
system, and the Cessna’s price of roughly
$150 is a bargain. Being able to fly without
concern for those flying on other RC
frequencies is a plus, and having that
capability in a micro-flight model is
tremendously impressive.
Micro flight is on the cutting edge of new
technology. It is rapidly outgrowing the
image held by some that smaller and lighter is
somehow inferior, and it is becoming a
significant category of modeling. As evidence
of this, nearly 1,000 people from more than
30 countries subscribe to the online monthly
micro-flight resource called RC Micro World.
The AMA Web site has good micro-flight
information and MA Sport Aviator offers a
number of micro-flight articles including “A
Free Guide to Indoor RC Flying,” with many
photos and details. MA
Sources:
Air Midi Micros
(775) 783-8545
www.airmidimicros.com
Bob Selman Designs
(417) 358-9521
www.bsdmicrorc.com
RC Micro World
www.cloud9rc.com
AMA
www.modelaircraft.org
MA Sport Aviator
www.masportaviator.com
