116 MODEL AVIATION
THE RESULTS ARE in from the AMA Contest Board vote on
RC Aerobatics rules changes. The main news is that there will be
a new Masters (AMA event 404) schedule for at least 2005-2006.
Following is the new 2005 schedule and detailed descriptions of
the new maneuvers.
1) Takeoff (U) K=1
2) Stall Turn, 11⁄4 Rolls Up, 3⁄4 Roll Down, Exit Inverted (U)
K=4
3) Half Outside Loop, 2/4 Roll on Exit K=2
4) Reverse Avalanche from Top with 1 Positive Snap at
Bottom (D) K=4
5) Half Loop with Full Roll Out K=2
6) 45 Degree Pyramid Loop with Half Rolls on Up and Down
Legs (U) K=3
7) Humpty Bump, Push or Pull on Top, 1⁄4 Roll Up, 3⁄4 Roll
Down K=3
8) Quarter, Half, Quarter Roll (D) K=4
9) Half Inside Loop, 2/4 roll on Exit K=2
10) Vertical Square Eight from the Middle, Pilot’s Option (U)
K=4
11) Mid-Entry Figure Nine—Pull 3⁄4 Loop First, Half Roll
Down K=3
12) Slow Roll (D) K=3
13) Humpty Bump with Pilot’s Option K=2
14) Square Loop with 2/4 Point Rolls on All Sides. First 2/4 on
Up-Line (U) K=5
15) Stall Turn with 1⁄2 Rolls K=2
16) Inside-Outside Diamond Eight with 1/1, Full Rolls, on
Center 45s (D) K=5
Eric Henderson, 303 Shady Ln., Marlton NJ 08053; E-mail: [email protected]
RADIO CONTROL AEROBATICS
The Focus II ARF is proving to be a great-flying model. The color
scheme is easily modified to give an “individual” look.
This Focus II powered by an O.S. 1.60 with an ES 140 long pipe
(not shown) gives 86-decibel reading measured over grass.
A JR 10X radio is shown as an illustration of control selection for
in-flight mixture-knob options.
Throttle to AUX3 using programmable Mix-56 before setting up
remote “needle” settings.
10sig4.QXD 7/23/04 10:50 am Page 116
118 MODEL AVIATION
17) Immelmann Turn K=1
18) 45 Degree Down, One Positive Snap Roll (U) K=3
19) Top Hat with 3⁄4 Roll Up, 1⁄4 Roll Down, Exit Upright K=3
20) Reverse Knife-Edge (D) K=4
21) Half Square Loop with 1⁄2 Roll Up K=2
22) 2 1⁄2 Turn Spin, with 1⁄2 Roll on Horizontal Exit Line (U)
K=4
23) Landing (U) K=1
Total K-Factor=66
Following are the official descriptions of new maneuvers for
the 2005 season.
• 2) Stall Turn, 11⁄4 Rolls Up, 3⁄4 Roll Down, Exit Inverted: Model
pulls through one-quarter (1⁄4) loop to vertical flight, pauses,
performs one-and-one-quarter (1-1⁄4) rolls, pauses, performs a 180
degree stall turn in the direction of the maneuver to a vertical
dive, pauses, performs a three-quarter (3⁄4) roll in opposite
rotation, pauses, then pushes through one-quarter (1⁄4) loop to
recover in inverted level flight.
• 3) Half Outside Loop, 2/4 Roll on Exit: Model pushes from
inverted level flight and executes half (1⁄2) outside loop,
immediately followed by 2 of 4 point roll, and finishes flying
straight and level exactly 180 degrees from heading at entry.
Mix-56 graph shows curve that is left after running and setting
engine seven points of mix during throttle transitions.
On the JR 10X, Mix-52 is used to select and set an in-flight
mixture-override knob for adjustment.
Tell them you saw it in
“Model Aviation”
10sig4.QXD 7/23/04 10:50 am Page 118
October 2004 121
• 4) Reverse Avalanche from Top with 1
Positive Snap at Bottom: Model pulls
down into a loop. At the bottom it executes
one positive snap roll, recovers to
complete the loop, and finishes at top to
level inverted flight.
• 6) 45 Degree Pyramid Loop with Half
Rolls on Up and Down: Model passes
through center and pulls 135 degrees,
climbs, hesitates, executes one-half (1⁄2)
roll, hesitates, then pushes through 90
degree loop, hesitates, then executes onehalf
(1⁄2) roll, hesitates, then pulls through
135 degrees to level flight.
• 10) Vertical Square Eight from the
Middle, Pilot’s Option: Model passes
through center and pulls or pushes to
commence a square loop. When first
square loop is complete the model passes
through center again and performs a
second square loop exactly below or
above, opposite to the first loop.
• 11) Mid-Entry Figure Nine—Pull 3⁄4
Loop First, Half Roll Down: Model pulls
3⁄4 loop, hesitates, performs 1⁄2 roll on
down-line, hesitates, Pulls 1⁄4 loop. (Note
loop entry point does not have to dissect
down-line.)
• 14) Square Loop with 2/4 Point Rolls on
All Sides. First 2/4 on Up-Line: Model
passes through center and pulls through
one-quarter (1⁄4) loop and executes square
loop with corner segments of equal radius.
In each leg, model hesitates, performs a 2
of 4 point roll, hesitates again before
performing the next loop segment.
• 16) Inside-Outside Diamond Eight with
1/1, Full Rolls, on Center 45s: Model
passes through center and pulls one eighth
(1⁄8) loop to 45 degree up-line, draws
another straight line then pulls quarter (1⁄4)
loop, draws straight line, and pulls one
quarter loop (1⁄4). Model hesitates and
performs one roll (1/1), hesitates and
pushes one quarter loop (1⁄4) to 45 degree
up-line, draws line and then pushes one
quarter loop (1⁄4), draws straight line,
pushes one quarter loop (1⁄4), hesitates and
performs one roll (1/1), hesitates and pulls
one-eighth loop (1⁄8) to level flight.
I expect that 4—the Reverse
Avalanche—will initially catch the
Masters pilots’ attention. It has the snap at
the bottom of the loop. When you look
closer, you will see that the maneuver is
designed so that your model will be almost
level and upright just before for the snap
component. The snap will be a single snap
and will be performed into the wind. All of
these design decisions were calculated to
make the maneuver more executable.
What would our sport be without
something to debate? In this rules-change
cycle, the AMA Contest Board did not
pass all of the National Society of Radio
Controlled Aerobatics (NSRCA)
proposals. A total of 12 NSRCA proposals
were submitted; six passed and six were
turned down.
The AMA Contest Board chairman also
submitted five proposals. All of those
passed, and unfortunately some
contradicted the NSRCA 2004 survey
vote. The most controversial change will
probably be the Contest Board’s removal
of scoring landings and takeoffs for
accuracy and execution.
All of the NSRCA survey results
showed that the pilots wanted those two
maneuvers to remain scored, as they are
today. It is possible to conclude that the
Contest Board members appear to be out
of touch with the NSRCA membership.
The counter to that claim is that the
NSRCA does not represent all Aerobatics
pilots in the AMA. That is probably what
needs to be fixed rather than who submits
what proposal.
The NSRCA is dedicated to the
promotion of precision Aerobatics, and the
organization’s US membership is
approximately 600. (Only US/AMA
members are eligible to vote on AMA
rules changes.) When not all AMA
members in the USA are included in ruleschange
surveys, it really does cause a
problem for AMA Contest Board
members. They can’t be sure that the
NSRCA voting data are representative of
the AMA Pattern fliers in their AMA
districts.
Aviastar 2.0 cubic inch engine shown
Specifications:
Displacement: 2.0 cubic inches
Bore: 1.42 inches
Stroke: 1.26 inches
Weight: 45.2 ounces
RPM Range: 1,800 to 10,000 rpm
Power: 4.3 hp @ 10,000 rpm
Only $309.99 at participating dealers
“In the Mandarin Chinese language,
if something is very good or done
very well, it is termed “Ding Hao”.
We found the Aviastar 150 to be one
Ding Hao engine.”
Clarence Lee, R/C Modeler Magazine, January 2000
• Powerful
• Quality Workmanship
• Superior Metallurgy
• Now available in 4 popular large sizes
• 1.20 cubic inch
• 1.50 cubic inch
• 1.80 cubic inch
• 2.0 cubic inch
• Available at leading hobby shops
Exclusively distributed in North America by:
SIG Manufacturing Company, Inc. • P.O. Box 520 • Montezuma, IA 50171-0520 • Phone: 641-623-5154
Visit our web site: www.sigmfg.com
10sig4.QXD 7/23/04 10:50 am Page 121
In several instances, AMA Contest
Board members have actually taken some
responsible steps and polled their AMA
district members who were known to fly
Pattern. That was because the NSRCA
survey neither went to all of the Pattern
pilots nor were the results grouped by
AMA districts.
To represent the Pattern community as
a whole, the NSRCA needs to reach out to
all Pattern pilots and “register” them in the
NSRCA database. This information could
easily be captured at the local contests.
Then, when an AMA rules cycle is upon
us, the NSRCA could send its latest survey
to all of the AMA members in the
database—not just fee-paying NSRCA
members.
The voting results could then be
tabulated by the AMA district while being
totaled. This would provide each AMA
Contest Board member a fully
representative picture of what the Pattern
pilots in the district would like him or her
to approve or not approve, as the case may
be.
One NSRCA proposal that has failed
two times in a row was to have a Snap
Roll in the Intermediate class (AMA event
402). It continues to be the conflicting
opinion of the AMA Contest Board that a
Snap Roll is too much for this class to
perform in contest conditions. This leaves
the class with a downwind exit and still
short of two maneuvers. This is a case in
which an AMA district vote tally could
well have changed the vote of the board
members.
The new Focus II is proving to be an
excellent-flying airplane. In most cases it
requires no roll couple mixing or any other
transmitter tricks. The accompanying
picture is of my Focus II powered by an
O.S. 1.60 engine with an ES 140 long
pipe. This setup gives outstanding vertical
performance with quiet sub-90-decibel
readings.
The airplane uses a mixture carburetor
that lets you dial exact fuel/air mixture
settings at multiple points on your throttle
travel. This gives smooth transition with
tuned-pipe configurations. The mixture
carburetor uses two servos: one to operate
the throttle air valve and one to
independently operate the fuel-mixture
valve. To illustrate the concepts and
operation of a mixture carburetor,
following is a sample coding of a JR 10X
radio.
The mixture lever/arm on a mixture
carburetor tracks, but not at the same rates,
with the throttle arm so that you can
optimize the fuel mixture at seven points
in the throttle range. A third channel is
used to allow a run-time override of the
settings. Most people are setting this up on
“AUX4” and using the rotary knob to lean
out or richen the mixture during setup or
even later flights.
The drawback of using a servo channel
like this is that you can influence the
mixture way too much with accidental
motion of the rotary knob. It is easy to go
way outside the operating parameters of
the carburetor’s virtual needle settings.
(There is no external needle valve on these
carburetors.)
A more ideal setup would be to limit
the effectiveness of the master mixture
override knob without reducing the
endpoints of the mixture channel. The
popular and current method is to plug the
mixture servo into AUX4 and mix throttle
(“Ch-1”) with AUX4 normal operation.
Then use AUX4 as a rotary channel with
full throws.
An alternative to doing this is to turn
122 MODEL AVIATION
OWN A MACHINE SHOP
1-800-476-4849
O r V i s i t u s a t w w w.smithy.com
GUARANTEED To pay for itself! FREE!
Info Kit
FREE!
Info Kit
Call
Today!
“I can fix ‘most anything. I don’t know how I lived
without my Smithy. It paid for itself in no time.”
• Easy to use – No
experience
required.
• Versatile – Fix or
make almost anything.
• Affordalbe-- 6
models starting
at $995.
• CNC Compatible
Do It Yourself on a Smithy Lathe•Mill•Drill!
off AUX4 as a channel and use it only as a
rotary control. Then you plug the mixture
servo into “AUX3,” and mix AUX4 and
throttle into AUX3. This allows you to
have the necessary big throws on the
throttle-to-mixture servo but small throws
from the master mixture-override knob.
It’s sort of like having a range limiter on
your needle valve of a trainer.
The actual coding is as follows:
1) Plug servos into Ch-1 (Throttle) and
AUX (mixture control).
2) Use code 17 to set AUX3 and AUX4
to INH.
3) Choose a mix from 56 to 58 for Ch-1
to AUX3. Select Curve and EXPO
and set mix to NORMAL.
4) Preset all the point mixes to
approximately 50% for subsequent
adjustment when running the engine.
5) Choose a mix from 51 to 55 for
AUX4 to AUX3.
6) Set mix type to ORIG. (This makes
AUX4 knob the throws of the
endpoint settings.)
7) Set roughly 20% mix each way on
the AUX4 to AUX3 mixes. It is
normally set up as turn clockwise to
go leaner and counterclockwise to
richen. You should be able to set it
up so that it has the effect of
approximately three clicks of a
conventional needle either way.
Then if you are operating it in the
air, you can’t set the mixture
override too far away from its
original setting.
A common use of the override
knob is to predial in a lean setting.
Then if the engine “loads up” on
takeoff, the mix can be selected for a
few seconds to clear the engine.
8) You can put the override mix on a
switch so that it can be disabled if
you are happy with the MC
performance and don’t want
accidental override to occur.
If you would like a Word-file copy of
these mixture settings on a JR 10X or
XP8103, please E-mail me. MA
10sig4.QXD 7/23/04 10:51 am Page 122
Edition: Model Aviation - 2004/10
Page Numbers: 116,118,121,122
Edition: Model Aviation - 2004/10
Page Numbers: 116,118,121,122
116 MODEL AVIATION
THE RESULTS ARE in from the AMA Contest Board vote on
RC Aerobatics rules changes. The main news is that there will be
a new Masters (AMA event 404) schedule for at least 2005-2006.
Following is the new 2005 schedule and detailed descriptions of
the new maneuvers.
1) Takeoff (U) K=1
2) Stall Turn, 11⁄4 Rolls Up, 3⁄4 Roll Down, Exit Inverted (U)
K=4
3) Half Outside Loop, 2/4 Roll on Exit K=2
4) Reverse Avalanche from Top with 1 Positive Snap at
Bottom (D) K=4
5) Half Loop with Full Roll Out K=2
6) 45 Degree Pyramid Loop with Half Rolls on Up and Down
Legs (U) K=3
7) Humpty Bump, Push or Pull on Top, 1⁄4 Roll Up, 3⁄4 Roll
Down K=3
8) Quarter, Half, Quarter Roll (D) K=4
9) Half Inside Loop, 2/4 roll on Exit K=2
10) Vertical Square Eight from the Middle, Pilot’s Option (U)
K=4
11) Mid-Entry Figure Nine—Pull 3⁄4 Loop First, Half Roll
Down K=3
12) Slow Roll (D) K=3
13) Humpty Bump with Pilot’s Option K=2
14) Square Loop with 2/4 Point Rolls on All Sides. First 2/4 on
Up-Line (U) K=5
15) Stall Turn with 1⁄2 Rolls K=2
16) Inside-Outside Diamond Eight with 1/1, Full Rolls, on
Center 45s (D) K=5
Eric Henderson, 303 Shady Ln., Marlton NJ 08053; E-mail: [email protected]
RADIO CONTROL AEROBATICS
The Focus II ARF is proving to be a great-flying model. The color
scheme is easily modified to give an “individual” look.
This Focus II powered by an O.S. 1.60 with an ES 140 long pipe
(not shown) gives 86-decibel reading measured over grass.
A JR 10X radio is shown as an illustration of control selection for
in-flight mixture-knob options.
Throttle to AUX3 using programmable Mix-56 before setting up
remote “needle” settings.
10sig4.QXD 7/23/04 10:50 am Page 116
118 MODEL AVIATION
17) Immelmann Turn K=1
18) 45 Degree Down, One Positive Snap Roll (U) K=3
19) Top Hat with 3⁄4 Roll Up, 1⁄4 Roll Down, Exit Upright K=3
20) Reverse Knife-Edge (D) K=4
21) Half Square Loop with 1⁄2 Roll Up K=2
22) 2 1⁄2 Turn Spin, with 1⁄2 Roll on Horizontal Exit Line (U)
K=4
23) Landing (U) K=1
Total K-Factor=66
Following are the official descriptions of new maneuvers for
the 2005 season.
• 2) Stall Turn, 11⁄4 Rolls Up, 3⁄4 Roll Down, Exit Inverted: Model
pulls through one-quarter (1⁄4) loop to vertical flight, pauses,
performs one-and-one-quarter (1-1⁄4) rolls, pauses, performs a 180
degree stall turn in the direction of the maneuver to a vertical
dive, pauses, performs a three-quarter (3⁄4) roll in opposite
rotation, pauses, then pushes through one-quarter (1⁄4) loop to
recover in inverted level flight.
• 3) Half Outside Loop, 2/4 Roll on Exit: Model pushes from
inverted level flight and executes half (1⁄2) outside loop,
immediately followed by 2 of 4 point roll, and finishes flying
straight and level exactly 180 degrees from heading at entry.
Mix-56 graph shows curve that is left after running and setting
engine seven points of mix during throttle transitions.
On the JR 10X, Mix-52 is used to select and set an in-flight
mixture-override knob for adjustment.
Tell them you saw it in
“Model Aviation”
10sig4.QXD 7/23/04 10:50 am Page 118
October 2004 121
• 4) Reverse Avalanche from Top with 1
Positive Snap at Bottom: Model pulls
down into a loop. At the bottom it executes
one positive snap roll, recovers to
complete the loop, and finishes at top to
level inverted flight.
• 6) 45 Degree Pyramid Loop with Half
Rolls on Up and Down: Model passes
through center and pulls 135 degrees,
climbs, hesitates, executes one-half (1⁄2)
roll, hesitates, then pushes through 90
degree loop, hesitates, then executes onehalf
(1⁄2) roll, hesitates, then pulls through
135 degrees to level flight.
• 10) Vertical Square Eight from the
Middle, Pilot’s Option: Model passes
through center and pulls or pushes to
commence a square loop. When first
square loop is complete the model passes
through center again and performs a
second square loop exactly below or
above, opposite to the first loop.
• 11) Mid-Entry Figure Nine—Pull 3⁄4
Loop First, Half Roll Down: Model pulls
3⁄4 loop, hesitates, performs 1⁄2 roll on
down-line, hesitates, Pulls 1⁄4 loop. (Note
loop entry point does not have to dissect
down-line.)
• 14) Square Loop with 2/4 Point Rolls on
All Sides. First 2/4 on Up-Line: Model
passes through center and pulls through
one-quarter (1⁄4) loop and executes square
loop with corner segments of equal radius.
In each leg, model hesitates, performs a 2
of 4 point roll, hesitates again before
performing the next loop segment.
• 16) Inside-Outside Diamond Eight with
1/1, Full Rolls, on Center 45s: Model
passes through center and pulls one eighth
(1⁄8) loop to 45 degree up-line, draws
another straight line then pulls quarter (1⁄4)
loop, draws straight line, and pulls one
quarter loop (1⁄4). Model hesitates and
performs one roll (1/1), hesitates and
pushes one quarter loop (1⁄4) to 45 degree
up-line, draws line and then pushes one
quarter loop (1⁄4), draws straight line,
pushes one quarter loop (1⁄4), hesitates and
performs one roll (1/1), hesitates and pulls
one-eighth loop (1⁄8) to level flight.
I expect that 4—the Reverse
Avalanche—will initially catch the
Masters pilots’ attention. It has the snap at
the bottom of the loop. When you look
closer, you will see that the maneuver is
designed so that your model will be almost
level and upright just before for the snap
component. The snap will be a single snap
and will be performed into the wind. All of
these design decisions were calculated to
make the maneuver more executable.
What would our sport be without
something to debate? In this rules-change
cycle, the AMA Contest Board did not
pass all of the National Society of Radio
Controlled Aerobatics (NSRCA)
proposals. A total of 12 NSRCA proposals
were submitted; six passed and six were
turned down.
The AMA Contest Board chairman also
submitted five proposals. All of those
passed, and unfortunately some
contradicted the NSRCA 2004 survey
vote. The most controversial change will
probably be the Contest Board’s removal
of scoring landings and takeoffs for
accuracy and execution.
All of the NSRCA survey results
showed that the pilots wanted those two
maneuvers to remain scored, as they are
today. It is possible to conclude that the
Contest Board members appear to be out
of touch with the NSRCA membership.
The counter to that claim is that the
NSRCA does not represent all Aerobatics
pilots in the AMA. That is probably what
needs to be fixed rather than who submits
what proposal.
The NSRCA is dedicated to the
promotion of precision Aerobatics, and the
organization’s US membership is
approximately 600. (Only US/AMA
members are eligible to vote on AMA
rules changes.) When not all AMA
members in the USA are included in ruleschange
surveys, it really does cause a
problem for AMA Contest Board
members. They can’t be sure that the
NSRCA voting data are representative of
the AMA Pattern fliers in their AMA
districts.
Aviastar 2.0 cubic inch engine shown
Specifications:
Displacement: 2.0 cubic inches
Bore: 1.42 inches
Stroke: 1.26 inches
Weight: 45.2 ounces
RPM Range: 1,800 to 10,000 rpm
Power: 4.3 hp @ 10,000 rpm
Only $309.99 at participating dealers
“In the Mandarin Chinese language,
if something is very good or done
very well, it is termed “Ding Hao”.
We found the Aviastar 150 to be one
Ding Hao engine.”
Clarence Lee, R/C Modeler Magazine, January 2000
• Powerful
• Quality Workmanship
• Superior Metallurgy
• Now available in 4 popular large sizes
• 1.20 cubic inch
• 1.50 cubic inch
• 1.80 cubic inch
• 2.0 cubic inch
• Available at leading hobby shops
Exclusively distributed in North America by:
SIG Manufacturing Company, Inc. • P.O. Box 520 • Montezuma, IA 50171-0520 • Phone: 641-623-5154
Visit our web site: www.sigmfg.com
10sig4.QXD 7/23/04 10:50 am Page 121
In several instances, AMA Contest
Board members have actually taken some
responsible steps and polled their AMA
district members who were known to fly
Pattern. That was because the NSRCA
survey neither went to all of the Pattern
pilots nor were the results grouped by
AMA districts.
To represent the Pattern community as
a whole, the NSRCA needs to reach out to
all Pattern pilots and “register” them in the
NSRCA database. This information could
easily be captured at the local contests.
Then, when an AMA rules cycle is upon
us, the NSRCA could send its latest survey
to all of the AMA members in the
database—not just fee-paying NSRCA
members.
The voting results could then be
tabulated by the AMA district while being
totaled. This would provide each AMA
Contest Board member a fully
representative picture of what the Pattern
pilots in the district would like him or her
to approve or not approve, as the case may
be.
One NSRCA proposal that has failed
two times in a row was to have a Snap
Roll in the Intermediate class (AMA event
402). It continues to be the conflicting
opinion of the AMA Contest Board that a
Snap Roll is too much for this class to
perform in contest conditions. This leaves
the class with a downwind exit and still
short of two maneuvers. This is a case in
which an AMA district vote tally could
well have changed the vote of the board
members.
The new Focus II is proving to be an
excellent-flying airplane. In most cases it
requires no roll couple mixing or any other
transmitter tricks. The accompanying
picture is of my Focus II powered by an
O.S. 1.60 engine with an ES 140 long
pipe. This setup gives outstanding vertical
performance with quiet sub-90-decibel
readings.
The airplane uses a mixture carburetor
that lets you dial exact fuel/air mixture
settings at multiple points on your throttle
travel. This gives smooth transition with
tuned-pipe configurations. The mixture
carburetor uses two servos: one to operate
the throttle air valve and one to
independently operate the fuel-mixture
valve. To illustrate the concepts and
operation of a mixture carburetor,
following is a sample coding of a JR 10X
radio.
The mixture lever/arm on a mixture
carburetor tracks, but not at the same rates,
with the throttle arm so that you can
optimize the fuel mixture at seven points
in the throttle range. A third channel is
used to allow a run-time override of the
settings. Most people are setting this up on
“AUX4” and using the rotary knob to lean
out or richen the mixture during setup or
even later flights.
The drawback of using a servo channel
like this is that you can influence the
mixture way too much with accidental
motion of the rotary knob. It is easy to go
way outside the operating parameters of
the carburetor’s virtual needle settings.
(There is no external needle valve on these
carburetors.)
A more ideal setup would be to limit
the effectiveness of the master mixture
override knob without reducing the
endpoints of the mixture channel. The
popular and current method is to plug the
mixture servo into AUX4 and mix throttle
(“Ch-1”) with AUX4 normal operation.
Then use AUX4 as a rotary channel with
full throws.
An alternative to doing this is to turn
122 MODEL AVIATION
OWN A MACHINE SHOP
1-800-476-4849
O r V i s i t u s a t w w w.smithy.com
GUARANTEED To pay for itself! FREE!
Info Kit
FREE!
Info Kit
Call
Today!
“I can fix ‘most anything. I don’t know how I lived
without my Smithy. It paid for itself in no time.”
• Easy to use – No
experience
required.
• Versatile – Fix or
make almost anything.
• Affordalbe-- 6
models starting
at $995.
• CNC Compatible
Do It Yourself on a Smithy Lathe•Mill•Drill!
off AUX4 as a channel and use it only as a
rotary control. Then you plug the mixture
servo into “AUX3,” and mix AUX4 and
throttle into AUX3. This allows you to
have the necessary big throws on the
throttle-to-mixture servo but small throws
from the master mixture-override knob.
It’s sort of like having a range limiter on
your needle valve of a trainer.
The actual coding is as follows:
1) Plug servos into Ch-1 (Throttle) and
AUX (mixture control).
2) Use code 17 to set AUX3 and AUX4
to INH.
3) Choose a mix from 56 to 58 for Ch-1
to AUX3. Select Curve and EXPO
and set mix to NORMAL.
4) Preset all the point mixes to
approximately 50% for subsequent
adjustment when running the engine.
5) Choose a mix from 51 to 55 for
AUX4 to AUX3.
6) Set mix type to ORIG. (This makes
AUX4 knob the throws of the
endpoint settings.)
7) Set roughly 20% mix each way on
the AUX4 to AUX3 mixes. It is
normally set up as turn clockwise to
go leaner and counterclockwise to
richen. You should be able to set it
up so that it has the effect of
approximately three clicks of a
conventional needle either way.
Then if you are operating it in the
air, you can’t set the mixture
override too far away from its
original setting.
A common use of the override
knob is to predial in a lean setting.
Then if the engine “loads up” on
takeoff, the mix can be selected for a
few seconds to clear the engine.
8) You can put the override mix on a
switch so that it can be disabled if
you are happy with the MC
performance and don’t want
accidental override to occur.
If you would like a Word-file copy of
these mixture settings on a JR 10X or
XP8103, please E-mail me. MA
10sig4.QXD 7/23/04 10:51 am Page 122
Edition: Model Aviation - 2004/10
Page Numbers: 116,118,121,122
116 MODEL AVIATION
THE RESULTS ARE in from the AMA Contest Board vote on
RC Aerobatics rules changes. The main news is that there will be
a new Masters (AMA event 404) schedule for at least 2005-2006.
Following is the new 2005 schedule and detailed descriptions of
the new maneuvers.
1) Takeoff (U) K=1
2) Stall Turn, 11⁄4 Rolls Up, 3⁄4 Roll Down, Exit Inverted (U)
K=4
3) Half Outside Loop, 2/4 Roll on Exit K=2
4) Reverse Avalanche from Top with 1 Positive Snap at
Bottom (D) K=4
5) Half Loop with Full Roll Out K=2
6) 45 Degree Pyramid Loop with Half Rolls on Up and Down
Legs (U) K=3
7) Humpty Bump, Push or Pull on Top, 1⁄4 Roll Up, 3⁄4 Roll
Down K=3
8) Quarter, Half, Quarter Roll (D) K=4
9) Half Inside Loop, 2/4 roll on Exit K=2
10) Vertical Square Eight from the Middle, Pilot’s Option (U)
K=4
11) Mid-Entry Figure Nine—Pull 3⁄4 Loop First, Half Roll
Down K=3
12) Slow Roll (D) K=3
13) Humpty Bump with Pilot’s Option K=2
14) Square Loop with 2/4 Point Rolls on All Sides. First 2/4 on
Up-Line (U) K=5
15) Stall Turn with 1⁄2 Rolls K=2
16) Inside-Outside Diamond Eight with 1/1, Full Rolls, on
Center 45s (D) K=5
Eric Henderson, 303 Shady Ln., Marlton NJ 08053; E-mail: [email protected]
RADIO CONTROL AEROBATICS
The Focus II ARF is proving to be a great-flying model. The color
scheme is easily modified to give an “individual” look.
This Focus II powered by an O.S. 1.60 with an ES 140 long pipe
(not shown) gives 86-decibel reading measured over grass.
A JR 10X radio is shown as an illustration of control selection for
in-flight mixture-knob options.
Throttle to AUX3 using programmable Mix-56 before setting up
remote “needle” settings.
10sig4.QXD 7/23/04 10:50 am Page 116
118 MODEL AVIATION
17) Immelmann Turn K=1
18) 45 Degree Down, One Positive Snap Roll (U) K=3
19) Top Hat with 3⁄4 Roll Up, 1⁄4 Roll Down, Exit Upright K=3
20) Reverse Knife-Edge (D) K=4
21) Half Square Loop with 1⁄2 Roll Up K=2
22) 2 1⁄2 Turn Spin, with 1⁄2 Roll on Horizontal Exit Line (U)
K=4
23) Landing (U) K=1
Total K-Factor=66
Following are the official descriptions of new maneuvers for
the 2005 season.
• 2) Stall Turn, 11⁄4 Rolls Up, 3⁄4 Roll Down, Exit Inverted: Model
pulls through one-quarter (1⁄4) loop to vertical flight, pauses,
performs one-and-one-quarter (1-1⁄4) rolls, pauses, performs a 180
degree stall turn in the direction of the maneuver to a vertical
dive, pauses, performs a three-quarter (3⁄4) roll in opposite
rotation, pauses, then pushes through one-quarter (1⁄4) loop to
recover in inverted level flight.
• 3) Half Outside Loop, 2/4 Roll on Exit: Model pushes from
inverted level flight and executes half (1⁄2) outside loop,
immediately followed by 2 of 4 point roll, and finishes flying
straight and level exactly 180 degrees from heading at entry.
Mix-56 graph shows curve that is left after running and setting
engine seven points of mix during throttle transitions.
On the JR 10X, Mix-52 is used to select and set an in-flight
mixture-override knob for adjustment.
Tell them you saw it in
“Model Aviation”
10sig4.QXD 7/23/04 10:50 am Page 118
October 2004 121
• 4) Reverse Avalanche from Top with 1
Positive Snap at Bottom: Model pulls
down into a loop. At the bottom it executes
one positive snap roll, recovers to
complete the loop, and finishes at top to
level inverted flight.
• 6) 45 Degree Pyramid Loop with Half
Rolls on Up and Down: Model passes
through center and pulls 135 degrees,
climbs, hesitates, executes one-half (1⁄2)
roll, hesitates, then pushes through 90
degree loop, hesitates, then executes onehalf
(1⁄2) roll, hesitates, then pulls through
135 degrees to level flight.
• 10) Vertical Square Eight from the
Middle, Pilot’s Option: Model passes
through center and pulls or pushes to
commence a square loop. When first
square loop is complete the model passes
through center again and performs a
second square loop exactly below or
above, opposite to the first loop.
• 11) Mid-Entry Figure Nine—Pull 3⁄4
Loop First, Half Roll Down: Model pulls
3⁄4 loop, hesitates, performs 1⁄2 roll on
down-line, hesitates, Pulls 1⁄4 loop. (Note
loop entry point does not have to dissect
down-line.)
• 14) Square Loop with 2/4 Point Rolls on
All Sides. First 2/4 on Up-Line: Model
passes through center and pulls through
one-quarter (1⁄4) loop and executes square
loop with corner segments of equal radius.
In each leg, model hesitates, performs a 2
of 4 point roll, hesitates again before
performing the next loop segment.
• 16) Inside-Outside Diamond Eight with
1/1, Full Rolls, on Center 45s: Model
passes through center and pulls one eighth
(1⁄8) loop to 45 degree up-line, draws
another straight line then pulls quarter (1⁄4)
loop, draws straight line, and pulls one
quarter loop (1⁄4). Model hesitates and
performs one roll (1/1), hesitates and
pushes one quarter loop (1⁄4) to 45 degree
up-line, draws line and then pushes one
quarter loop (1⁄4), draws straight line,
pushes one quarter loop (1⁄4), hesitates and
performs one roll (1/1), hesitates and pulls
one-eighth loop (1⁄8) to level flight.
I expect that 4—the Reverse
Avalanche—will initially catch the
Masters pilots’ attention. It has the snap at
the bottom of the loop. When you look
closer, you will see that the maneuver is
designed so that your model will be almost
level and upright just before for the snap
component. The snap will be a single snap
and will be performed into the wind. All of
these design decisions were calculated to
make the maneuver more executable.
What would our sport be without
something to debate? In this rules-change
cycle, the AMA Contest Board did not
pass all of the National Society of Radio
Controlled Aerobatics (NSRCA)
proposals. A total of 12 NSRCA proposals
were submitted; six passed and six were
turned down.
The AMA Contest Board chairman also
submitted five proposals. All of those
passed, and unfortunately some
contradicted the NSRCA 2004 survey
vote. The most controversial change will
probably be the Contest Board’s removal
of scoring landings and takeoffs for
accuracy and execution.
All of the NSRCA survey results
showed that the pilots wanted those two
maneuvers to remain scored, as they are
today. It is possible to conclude that the
Contest Board members appear to be out
of touch with the NSRCA membership.
The counter to that claim is that the
NSRCA does not represent all Aerobatics
pilots in the AMA. That is probably what
needs to be fixed rather than who submits
what proposal.
The NSRCA is dedicated to the
promotion of precision Aerobatics, and the
organization’s US membership is
approximately 600. (Only US/AMA
members are eligible to vote on AMA
rules changes.) When not all AMA
members in the USA are included in ruleschange
surveys, it really does cause a
problem for AMA Contest Board
members. They can’t be sure that the
NSRCA voting data are representative of
the AMA Pattern fliers in their AMA
districts.
Aviastar 2.0 cubic inch engine shown
Specifications:
Displacement: 2.0 cubic inches
Bore: 1.42 inches
Stroke: 1.26 inches
Weight: 45.2 ounces
RPM Range: 1,800 to 10,000 rpm
Power: 4.3 hp @ 10,000 rpm
Only $309.99 at participating dealers
“In the Mandarin Chinese language,
if something is very good or done
very well, it is termed “Ding Hao”.
We found the Aviastar 150 to be one
Ding Hao engine.”
Clarence Lee, R/C Modeler Magazine, January 2000
• Powerful
• Quality Workmanship
• Superior Metallurgy
• Now available in 4 popular large sizes
• 1.20 cubic inch
• 1.50 cubic inch
• 1.80 cubic inch
• 2.0 cubic inch
• Available at leading hobby shops
Exclusively distributed in North America by:
SIG Manufacturing Company, Inc. • P.O. Box 520 • Montezuma, IA 50171-0520 • Phone: 641-623-5154
Visit our web site: www.sigmfg.com
10sig4.QXD 7/23/04 10:50 am Page 121
In several instances, AMA Contest
Board members have actually taken some
responsible steps and polled their AMA
district members who were known to fly
Pattern. That was because the NSRCA
survey neither went to all of the Pattern
pilots nor were the results grouped by
AMA districts.
To represent the Pattern community as
a whole, the NSRCA needs to reach out to
all Pattern pilots and “register” them in the
NSRCA database. This information could
easily be captured at the local contests.
Then, when an AMA rules cycle is upon
us, the NSRCA could send its latest survey
to all of the AMA members in the
database—not just fee-paying NSRCA
members.
The voting results could then be
tabulated by the AMA district while being
totaled. This would provide each AMA
Contest Board member a fully
representative picture of what the Pattern
pilots in the district would like him or her
to approve or not approve, as the case may
be.
One NSRCA proposal that has failed
two times in a row was to have a Snap
Roll in the Intermediate class (AMA event
402). It continues to be the conflicting
opinion of the AMA Contest Board that a
Snap Roll is too much for this class to
perform in contest conditions. This leaves
the class with a downwind exit and still
short of two maneuvers. This is a case in
which an AMA district vote tally could
well have changed the vote of the board
members.
The new Focus II is proving to be an
excellent-flying airplane. In most cases it
requires no roll couple mixing or any other
transmitter tricks. The accompanying
picture is of my Focus II powered by an
O.S. 1.60 engine with an ES 140 long
pipe. This setup gives outstanding vertical
performance with quiet sub-90-decibel
readings.
The airplane uses a mixture carburetor
that lets you dial exact fuel/air mixture
settings at multiple points on your throttle
travel. This gives smooth transition with
tuned-pipe configurations. The mixture
carburetor uses two servos: one to operate
the throttle air valve and one to
independently operate the fuel-mixture
valve. To illustrate the concepts and
operation of a mixture carburetor,
following is a sample coding of a JR 10X
radio.
The mixture lever/arm on a mixture
carburetor tracks, but not at the same rates,
with the throttle arm so that you can
optimize the fuel mixture at seven points
in the throttle range. A third channel is
used to allow a run-time override of the
settings. Most people are setting this up on
“AUX4” and using the rotary knob to lean
out or richen the mixture during setup or
even later flights.
The drawback of using a servo channel
like this is that you can influence the
mixture way too much with accidental
motion of the rotary knob. It is easy to go
way outside the operating parameters of
the carburetor’s virtual needle settings.
(There is no external needle valve on these
carburetors.)
A more ideal setup would be to limit
the effectiveness of the master mixture
override knob without reducing the
endpoints of the mixture channel. The
popular and current method is to plug the
mixture servo into AUX4 and mix throttle
(“Ch-1”) with AUX4 normal operation.
Then use AUX4 as a rotary channel with
full throws.
An alternative to doing this is to turn
122 MODEL AVIATION
OWN A MACHINE SHOP
1-800-476-4849
O r V i s i t u s a t w w w.smithy.com
GUARANTEED To pay for itself! FREE!
Info Kit
FREE!
Info Kit
Call
Today!
“I can fix ‘most anything. I don’t know how I lived
without my Smithy. It paid for itself in no time.”
• Easy to use – No
experience
required.
• Versatile – Fix or
make almost anything.
• Affordalbe-- 6
models starting
at $995.
• CNC Compatible
Do It Yourself on a Smithy Lathe•Mill•Drill!
off AUX4 as a channel and use it only as a
rotary control. Then you plug the mixture
servo into “AUX3,” and mix AUX4 and
throttle into AUX3. This allows you to
have the necessary big throws on the
throttle-to-mixture servo but small throws
from the master mixture-override knob.
It’s sort of like having a range limiter on
your needle valve of a trainer.
The actual coding is as follows:
1) Plug servos into Ch-1 (Throttle) and
AUX (mixture control).
2) Use code 17 to set AUX3 and AUX4
to INH.
3) Choose a mix from 56 to 58 for Ch-1
to AUX3. Select Curve and EXPO
and set mix to NORMAL.
4) Preset all the point mixes to
approximately 50% for subsequent
adjustment when running the engine.
5) Choose a mix from 51 to 55 for
AUX4 to AUX3.
6) Set mix type to ORIG. (This makes
AUX4 knob the throws of the
endpoint settings.)
7) Set roughly 20% mix each way on
the AUX4 to AUX3 mixes. It is
normally set up as turn clockwise to
go leaner and counterclockwise to
richen. You should be able to set it
up so that it has the effect of
approximately three clicks of a
conventional needle either way.
Then if you are operating it in the
air, you can’t set the mixture
override too far away from its
original setting.
A common use of the override
knob is to predial in a lean setting.
Then if the engine “loads up” on
takeoff, the mix can be selected for a
few seconds to clear the engine.
8) You can put the override mix on a
switch so that it can be disabled if
you are happy with the MC
performance and don’t want
accidental override to occur.
If you would like a Word-file copy of
these mixture settings on a JR 10X or
XP8103, please E-mail me. MA
10sig4.QXD 7/23/04 10:51 am Page 122
Edition: Model Aviation - 2004/10
Page Numbers: 116,118,121,122
116 MODEL AVIATION
THE RESULTS ARE in from the AMA Contest Board vote on
RC Aerobatics rules changes. The main news is that there will be
a new Masters (AMA event 404) schedule for at least 2005-2006.
Following is the new 2005 schedule and detailed descriptions of
the new maneuvers.
1) Takeoff (U) K=1
2) Stall Turn, 11⁄4 Rolls Up, 3⁄4 Roll Down, Exit Inverted (U)
K=4
3) Half Outside Loop, 2/4 Roll on Exit K=2
4) Reverse Avalanche from Top with 1 Positive Snap at
Bottom (D) K=4
5) Half Loop with Full Roll Out K=2
6) 45 Degree Pyramid Loop with Half Rolls on Up and Down
Legs (U) K=3
7) Humpty Bump, Push or Pull on Top, 1⁄4 Roll Up, 3⁄4 Roll
Down K=3
8) Quarter, Half, Quarter Roll (D) K=4
9) Half Inside Loop, 2/4 roll on Exit K=2
10) Vertical Square Eight from the Middle, Pilot’s Option (U)
K=4
11) Mid-Entry Figure Nine—Pull 3⁄4 Loop First, Half Roll
Down K=3
12) Slow Roll (D) K=3
13) Humpty Bump with Pilot’s Option K=2
14) Square Loop with 2/4 Point Rolls on All Sides. First 2/4 on
Up-Line (U) K=5
15) Stall Turn with 1⁄2 Rolls K=2
16) Inside-Outside Diamond Eight with 1/1, Full Rolls, on
Center 45s (D) K=5
Eric Henderson, 303 Shady Ln., Marlton NJ 08053; E-mail: [email protected]
RADIO CONTROL AEROBATICS
The Focus II ARF is proving to be a great-flying model. The color
scheme is easily modified to give an “individual” look.
This Focus II powered by an O.S. 1.60 with an ES 140 long pipe
(not shown) gives 86-decibel reading measured over grass.
A JR 10X radio is shown as an illustration of control selection for
in-flight mixture-knob options.
Throttle to AUX3 using programmable Mix-56 before setting up
remote “needle” settings.
10sig4.QXD 7/23/04 10:50 am Page 116
118 MODEL AVIATION
17) Immelmann Turn K=1
18) 45 Degree Down, One Positive Snap Roll (U) K=3
19) Top Hat with 3⁄4 Roll Up, 1⁄4 Roll Down, Exit Upright K=3
20) Reverse Knife-Edge (D) K=4
21) Half Square Loop with 1⁄2 Roll Up K=2
22) 2 1⁄2 Turn Spin, with 1⁄2 Roll on Horizontal Exit Line (U)
K=4
23) Landing (U) K=1
Total K-Factor=66
Following are the official descriptions of new maneuvers for
the 2005 season.
• 2) Stall Turn, 11⁄4 Rolls Up, 3⁄4 Roll Down, Exit Inverted: Model
pulls through one-quarter (1⁄4) loop to vertical flight, pauses,
performs one-and-one-quarter (1-1⁄4) rolls, pauses, performs a 180
degree stall turn in the direction of the maneuver to a vertical
dive, pauses, performs a three-quarter (3⁄4) roll in opposite
rotation, pauses, then pushes through one-quarter (1⁄4) loop to
recover in inverted level flight.
• 3) Half Outside Loop, 2/4 Roll on Exit: Model pushes from
inverted level flight and executes half (1⁄2) outside loop,
immediately followed by 2 of 4 point roll, and finishes flying
straight and level exactly 180 degrees from heading at entry.
Mix-56 graph shows curve that is left after running and setting
engine seven points of mix during throttle transitions.
On the JR 10X, Mix-52 is used to select and set an in-flight
mixture-override knob for adjustment.
Tell them you saw it in
“Model Aviation”
10sig4.QXD 7/23/04 10:50 am Page 118
October 2004 121
• 4) Reverse Avalanche from Top with 1
Positive Snap at Bottom: Model pulls
down into a loop. At the bottom it executes
one positive snap roll, recovers to
complete the loop, and finishes at top to
level inverted flight.
• 6) 45 Degree Pyramid Loop with Half
Rolls on Up and Down: Model passes
through center and pulls 135 degrees,
climbs, hesitates, executes one-half (1⁄2)
roll, hesitates, then pushes through 90
degree loop, hesitates, then executes onehalf
(1⁄2) roll, hesitates, then pulls through
135 degrees to level flight.
• 10) Vertical Square Eight from the
Middle, Pilot’s Option: Model passes
through center and pulls or pushes to
commence a square loop. When first
square loop is complete the model passes
through center again and performs a
second square loop exactly below or
above, opposite to the first loop.
• 11) Mid-Entry Figure Nine—Pull 3⁄4
Loop First, Half Roll Down: Model pulls
3⁄4 loop, hesitates, performs 1⁄2 roll on
down-line, hesitates, Pulls 1⁄4 loop. (Note
loop entry point does not have to dissect
down-line.)
• 14) Square Loop with 2/4 Point Rolls on
All Sides. First 2/4 on Up-Line: Model
passes through center and pulls through
one-quarter (1⁄4) loop and executes square
loop with corner segments of equal radius.
In each leg, model hesitates, performs a 2
of 4 point roll, hesitates again before
performing the next loop segment.
• 16) Inside-Outside Diamond Eight with
1/1, Full Rolls, on Center 45s: Model
passes through center and pulls one eighth
(1⁄8) loop to 45 degree up-line, draws
another straight line then pulls quarter (1⁄4)
loop, draws straight line, and pulls one
quarter loop (1⁄4). Model hesitates and
performs one roll (1/1), hesitates and
pushes one quarter loop (1⁄4) to 45 degree
up-line, draws line and then pushes one
quarter loop (1⁄4), draws straight line,
pushes one quarter loop (1⁄4), hesitates and
performs one roll (1/1), hesitates and pulls
one-eighth loop (1⁄8) to level flight.
I expect that 4—the Reverse
Avalanche—will initially catch the
Masters pilots’ attention. It has the snap at
the bottom of the loop. When you look
closer, you will see that the maneuver is
designed so that your model will be almost
level and upright just before for the snap
component. The snap will be a single snap
and will be performed into the wind. All of
these design decisions were calculated to
make the maneuver more executable.
What would our sport be without
something to debate? In this rules-change
cycle, the AMA Contest Board did not
pass all of the National Society of Radio
Controlled Aerobatics (NSRCA)
proposals. A total of 12 NSRCA proposals
were submitted; six passed and six were
turned down.
The AMA Contest Board chairman also
submitted five proposals. All of those
passed, and unfortunately some
contradicted the NSRCA 2004 survey
vote. The most controversial change will
probably be the Contest Board’s removal
of scoring landings and takeoffs for
accuracy and execution.
All of the NSRCA survey results
showed that the pilots wanted those two
maneuvers to remain scored, as they are
today. It is possible to conclude that the
Contest Board members appear to be out
of touch with the NSRCA membership.
The counter to that claim is that the
NSRCA does not represent all Aerobatics
pilots in the AMA. That is probably what
needs to be fixed rather than who submits
what proposal.
The NSRCA is dedicated to the
promotion of precision Aerobatics, and the
organization’s US membership is
approximately 600. (Only US/AMA
members are eligible to vote on AMA
rules changes.) When not all AMA
members in the USA are included in ruleschange
surveys, it really does cause a
problem for AMA Contest Board
members. They can’t be sure that the
NSRCA voting data are representative of
the AMA Pattern fliers in their AMA
districts.
Aviastar 2.0 cubic inch engine shown
Specifications:
Displacement: 2.0 cubic inches
Bore: 1.42 inches
Stroke: 1.26 inches
Weight: 45.2 ounces
RPM Range: 1,800 to 10,000 rpm
Power: 4.3 hp @ 10,000 rpm
Only $309.99 at participating dealers
“In the Mandarin Chinese language,
if something is very good or done
very well, it is termed “Ding Hao”.
We found the Aviastar 150 to be one
Ding Hao engine.”
Clarence Lee, R/C Modeler Magazine, January 2000
• Powerful
• Quality Workmanship
• Superior Metallurgy
• Now available in 4 popular large sizes
• 1.20 cubic inch
• 1.50 cubic inch
• 1.80 cubic inch
• 2.0 cubic inch
• Available at leading hobby shops
Exclusively distributed in North America by:
SIG Manufacturing Company, Inc. • P.O. Box 520 • Montezuma, IA 50171-0520 • Phone: 641-623-5154
Visit our web site: www.sigmfg.com
10sig4.QXD 7/23/04 10:50 am Page 121
In several instances, AMA Contest
Board members have actually taken some
responsible steps and polled their AMA
district members who were known to fly
Pattern. That was because the NSRCA
survey neither went to all of the Pattern
pilots nor were the results grouped by
AMA districts.
To represent the Pattern community as
a whole, the NSRCA needs to reach out to
all Pattern pilots and “register” them in the
NSRCA database. This information could
easily be captured at the local contests.
Then, when an AMA rules cycle is upon
us, the NSRCA could send its latest survey
to all of the AMA members in the
database—not just fee-paying NSRCA
members.
The voting results could then be
tabulated by the AMA district while being
totaled. This would provide each AMA
Contest Board member a fully
representative picture of what the Pattern
pilots in the district would like him or her
to approve or not approve, as the case may
be.
One NSRCA proposal that has failed
two times in a row was to have a Snap
Roll in the Intermediate class (AMA event
402). It continues to be the conflicting
opinion of the AMA Contest Board that a
Snap Roll is too much for this class to
perform in contest conditions. This leaves
the class with a downwind exit and still
short of two maneuvers. This is a case in
which an AMA district vote tally could
well have changed the vote of the board
members.
The new Focus II is proving to be an
excellent-flying airplane. In most cases it
requires no roll couple mixing or any other
transmitter tricks. The accompanying
picture is of my Focus II powered by an
O.S. 1.60 engine with an ES 140 long
pipe. This setup gives outstanding vertical
performance with quiet sub-90-decibel
readings.
The airplane uses a mixture carburetor
that lets you dial exact fuel/air mixture
settings at multiple points on your throttle
travel. This gives smooth transition with
tuned-pipe configurations. The mixture
carburetor uses two servos: one to operate
the throttle air valve and one to
independently operate the fuel-mixture
valve. To illustrate the concepts and
operation of a mixture carburetor,
following is a sample coding of a JR 10X
radio.
The mixture lever/arm on a mixture
carburetor tracks, but not at the same rates,
with the throttle arm so that you can
optimize the fuel mixture at seven points
in the throttle range. A third channel is
used to allow a run-time override of the
settings. Most people are setting this up on
“AUX4” and using the rotary knob to lean
out or richen the mixture during setup or
even later flights.
The drawback of using a servo channel
like this is that you can influence the
mixture way too much with accidental
motion of the rotary knob. It is easy to go
way outside the operating parameters of
the carburetor’s virtual needle settings.
(There is no external needle valve on these
carburetors.)
A more ideal setup would be to limit
the effectiveness of the master mixture
override knob without reducing the
endpoints of the mixture channel. The
popular and current method is to plug the
mixture servo into AUX4 and mix throttle
(“Ch-1”) with AUX4 normal operation.
Then use AUX4 as a rotary channel with
full throws.
An alternative to doing this is to turn
122 MODEL AVIATION
OWN A MACHINE SHOP
1-800-476-4849
O r V i s i t u s a t w w w.smithy.com
GUARANTEED To pay for itself! FREE!
Info Kit
FREE!
Info Kit
Call
Today!
“I can fix ‘most anything. I don’t know how I lived
without my Smithy. It paid for itself in no time.”
• Easy to use – No
experience
required.
• Versatile – Fix or
make almost anything.
• Affordalbe-- 6
models starting
at $995.
• CNC Compatible
Do It Yourself on a Smithy Lathe•Mill•Drill!
off AUX4 as a channel and use it only as a
rotary control. Then you plug the mixture
servo into “AUX3,” and mix AUX4 and
throttle into AUX3. This allows you to
have the necessary big throws on the
throttle-to-mixture servo but small throws
from the master mixture-override knob.
It’s sort of like having a range limiter on
your needle valve of a trainer.
The actual coding is as follows:
1) Plug servos into Ch-1 (Throttle) and
AUX (mixture control).
2) Use code 17 to set AUX3 and AUX4
to INH.
3) Choose a mix from 56 to 58 for Ch-1
to AUX3. Select Curve and EXPO
and set mix to NORMAL.
4) Preset all the point mixes to
approximately 50% for subsequent
adjustment when running the engine.
5) Choose a mix from 51 to 55 for
AUX4 to AUX3.
6) Set mix type to ORIG. (This makes
AUX4 knob the throws of the
endpoint settings.)
7) Set roughly 20% mix each way on
the AUX4 to AUX3 mixes. It is
normally set up as turn clockwise to
go leaner and counterclockwise to
richen. You should be able to set it
up so that it has the effect of
approximately three clicks of a
conventional needle either way.
Then if you are operating it in the
air, you can’t set the mixture
override too far away from its
original setting.
A common use of the override
knob is to predial in a lean setting.
Then if the engine “loads up” on
takeoff, the mix can be selected for a
few seconds to clear the engine.
8) You can put the override mix on a
switch so that it can be disabled if
you are happy with the MC
performance and don’t want
accidental override to occur.
If you would like a Word-file copy of
these mixture settings on a JR 10X or
XP8103, please E-mail me. MA
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