146 MODEL AVIATION
THIS MONTH I will write about the
inaugural Hamster Dash at the 2004
Nats, the effect of model weight, and a
few methods of building a lightweight
Speedster.
Following the demise of .40-powered
Rat Racers, the racing community has
been looking for an event to replace it.
In 2002, the participants tried a .21-
powered racer. This size of power plant
is not a displacement that CL racers
have in their engine sheds. Not many
models powered with .21s were built.
The next size tried was a .15-
powered Rat Racer. This size caught on
because it is a displacement used in
other racing events. Racers
affectionately refer to the models used in
.15 Rat as “Hamsters.”
The North American Speed Society
(NASS) will hold the first Hamster Dash
on Tuesday, July 13, 2004, during the
Nats. It will be at the Speed site at the
CONTROL LINE SPEED
Dave Mark, Box 371, Fenton MI 48430; E-mail: [email protected]
Bill Hughes is holding his 1⁄2A Proto aircraft and his soon-to-bekitted
1⁄2A Speed model.
Ron Salo flies in the pylon at the 2002 Control Line World
Championships held in Sebnitz, Germany.
Len Waltemath, center, is the Jet record holder at 204.93 mph. Pilot Joey Mathison (L)
and pit crew Arlyn Valentine are shown with him.
07sig5.QXD 4/23/04 10:08 am Page 146
International Aeromodeling Center in
Muncie, Indiana, and will begin
following the completion of the day’s
scheduled events.
This unofficial event is the result of
much discussion on the Delphi Speed
Forum. Racers were asking if it would be
possible to use the Speed circles and
pylons to test their models. NASS then
made an offer to host the festivities and
supply awards for the fastest airplanes.
All models will be timed from a
standing start and for seven laps on the
fly. Awards suitable for framing will be
presented for both methods. The survey
on the Speed forum showed 18 for Proto
time and 15 for standard, so we will do
both. NASS will supply watches, contest
equipment, and awards. The contestants
will supply timers.
The regulations are as follows:
1) Models with .15 size engines max
(.1525).
2) Models must use two (2) lines sized
.014- x 60-feet plus all you want, minus 6
inches.
3) Times of models flown on 59-foot
6-inch lines will be adjusted to 60 feet
with a correction factor.
4) All models must have at least one
(1) wheel.
5) No asymmetric models allowed.
6) Models may be whipped for takeoff
only. When the wheel leaves the
ground the arm stops!
7) Hamsters, Goodyear racers, and
any model with a .15 on the nose
including purpose-built are welcome to
compete as long as they meet the above
criteria.
8) One-and-a-half laps are allowed to
enter the pylon.
9) Open-face exhaust or mini pipe
allowed. No tuned pipes.
10) Fuel of 10% nitro will be supplied
by contest management.
11) No one-blade propellers allowed.
The rules are subject to change until
the day of the contest with the intent of
obtaining maximum participation.
A few of the rules created a high level
of discussion. Rule 2 reflects the practice
of making lines 6 inches shorter than 60
feet, as is allowed by the rules for racing
and is used by all of the racers. They time
the flight based on 60-foot lines and
ignore the fact that the lines are shorter
than that. I don’t know how or why this
practice developed in the racing
community.
This practice of using short lines is the
reason for Rule 3: the correction factor to
bring the times back to a full 60-foot
length. This did generate a few offers by
Speed fliers to hold classes on the use of
measuring tapes and line construction!
The next item to cause discussion was
Rule 7, which specifically allows the use
July 2004 147
SG Model Engines
P.O. Box 280303
Northridge, CA 91328
Tel. (818) 472-8460
Engines, Accessories & Parts
Dealers
Welcome
Web Site: Shop.vendio.com/RossiEnginesUSA
WWW.PSPEC.COM
Complete engine and muffler packages are available.
VISIT US AT WWW.PSPEC.COM.
DEALER INQUIRIES WELCOME!
TWISTER 4-STROKE MUFFLERS & ELBOWS
PISTON/CYLINDER ASSEMBLIES
ULTRATHRUST MUFFLERS
PERFORMANCE SPECIALTIES
PO Box 3146 • Gardnerville, NV 89410
Phone: 775-265-7523 • Fax: 775-265-7522
of purpose-built models. This was
included in an attempt to invite Speed
fliers to put together a model for the
Hamster Dash.
The rule caused a few of the racers to
state that they would not stand a chance
against models designed for the event.
They felt that the 2-ounce tanks and
shutoff units would add weight that would
hold their speeds down. Some felt that the
larger wing and stabilizer area would
work against them.
Let’s look at these concerns beginning
with the wing-area issue. The average
Hamster has a wingspan between 22 and
24 inches and has a working elevator
across the full length of the stabilizer. The
large elevator is used to shake off speed
to make landings happen quicker in the
racing environment.
This should not present a problem in a
Speed run. Racing pilots are able to
groove these models in the traffic of a
race, so they will surely not find it
difficult to groove during a Speed run of
14 laps.
The wingspan is comparable to that
used in the Formula 40 event. Many
Speed models flown today use wing areas
much larger than those used in the past.
The increased wing area produces a
model that flies more smoothly, and it is
07sig5.QXD 4/23/04 10:08 am Page 147
much easier to land than the small models
of the past which simply dropped out of
the air when the engine quit.
The issue of model weight caused the
highest level of concern among the racers.
It was often stated that the lighter weight
of purpose-built models would give them
such a significant edge that it would make
the Rat Racers noncompetitive. After
reviewing last year’s Nats results, I
disagree.
The Hamster Dash will have two
timing components: the standing-start
mile and the on-the-fly 1⁄2 mile; in effect,
we have two separate events in one.
The standing-start one-mile timing will
probably go to a purpose-built model, or
as we will call it, a Formula 15. This
statement is based on reviewing the model
weights of the first three places in
Formula 40 and 1⁄2A Proto.
In Formula 40, first, second, and third
places went to models that weighed 23-28
ounces including fuel. One other model
fell within this range but didn’t place. The
rest entered in the event were heavier.
In 1⁄2A Proto, the first five places went to
models that ranged from 4.9 to 6.3 ounces
including fuel. There are two anomalies in
this group. The 6.3-ounce model came in
second and the 4.9-ounce model came in
fifth. The other three placing models
weighed 5.5, 5.1, and 5.6 ounces. I
conclude that lighter is much better in an
event where acceleration is a component.
Weight does not appear to be as
important in the events timed on-the-fly
that are not piped. In .21, sport models
ranged from 18.5 to 25 ounces. First place
went to a 22-ounce unit and second
through fifth places went to models
ranging between 22 and 25 ounces.
In D Speed, first- through fifth-place
entries weighed 43, 46, 40, 38, and 42
ounces respectively. I see no clear-cut
pattern here indicating that lighter is
totally necessary to place in a Speed
event, but Paul Gibeault, a NASS member
from Alberta, Canada, summed the issue
up with the statement, “A heavy-flying
Speed model is far superior to the lightest
Speed model that never sees a contest!”
Lighter is better in Speed models, but
this can be carried to extremes. I have
seen a few airplanes that were constructed
so light that they did not last one flight.
One thing that helps reduce weight is
to use a little magnesium Speed pan. It is
common on Formula 40 models to use a
DARP ([734] 266-7290) B Pan cut to 101⁄2
inches. This should be replaced with a
DARP Proto Pan cut to 51⁄4 inches long.
The width is narrowed to the same as the
B Pan. The Proto Pan allows the use of all
six hold-down screws on the Nelson .40.
The area that was pan is replaced with
a piece of 1⁄16 basswood that has been
soaked in water and wrapped over the end
of the pan that was cut off and left to dry.
This item is much lighter than a hollowedout
balsa block and much stronger.
The pan is hollowed out and thinned to
a thickness of .080 inch. It can be difficult
to measure the thickness of the pan. If you
have a drill press, set a small drill so that
it stops at roughly .080 inch to .100 inch
above the table. Drill the pan in the areas
that you plan to thin. Install a rotary file in
the chuck, and work the pan down to the
drill points and stop.
This method gives you a target area of
how far to take the thinning. The fins on
the Nelson should be milled down to 11⁄2
inches diameter. The propeller nut is
replaced with a nut made from 7075
aluminum.
The landing-gear strut should be
titanium, which can be obtained from
Glenn Lee ([630] 879-2558). Order a set
of Glenn’s 1-inch-diameter wheels. The
wheels come with brass hubs which
should be replaced with ones made from
aluminum.
This attention to detail should be
applied to every item in the model. The
result is a Formula 40 with a weight—
including fuel—of 21.5 ounces. The
results of the test flights will be in the next
column.
I am out of space for this time. I’ll be
back in three months. MA
148 MODEL AVIATION
07sig5.QXD 4/23/04 10:08 am Page 148
Edition: Model Aviation - 2004/07
Page Numbers: 146,147,148
Edition: Model Aviation - 2004/07
Page Numbers: 146,147,148
146 MODEL AVIATION
THIS MONTH I will write about the
inaugural Hamster Dash at the 2004
Nats, the effect of model weight, and a
few methods of building a lightweight
Speedster.
Following the demise of .40-powered
Rat Racers, the racing community has
been looking for an event to replace it.
In 2002, the participants tried a .21-
powered racer. This size of power plant
is not a displacement that CL racers
have in their engine sheds. Not many
models powered with .21s were built.
The next size tried was a .15-
powered Rat Racer. This size caught on
because it is a displacement used in
other racing events. Racers
affectionately refer to the models used in
.15 Rat as “Hamsters.”
The North American Speed Society
(NASS) will hold the first Hamster Dash
on Tuesday, July 13, 2004, during the
Nats. It will be at the Speed site at the
CONTROL LINE SPEED
Dave Mark, Box 371, Fenton MI 48430; E-mail: [email protected]
Bill Hughes is holding his 1⁄2A Proto aircraft and his soon-to-bekitted
1⁄2A Speed model.
Ron Salo flies in the pylon at the 2002 Control Line World
Championships held in Sebnitz, Germany.
Len Waltemath, center, is the Jet record holder at 204.93 mph. Pilot Joey Mathison (L)
and pit crew Arlyn Valentine are shown with him.
07sig5.QXD 4/23/04 10:08 am Page 146
International Aeromodeling Center in
Muncie, Indiana, and will begin
following the completion of the day’s
scheduled events.
This unofficial event is the result of
much discussion on the Delphi Speed
Forum. Racers were asking if it would be
possible to use the Speed circles and
pylons to test their models. NASS then
made an offer to host the festivities and
supply awards for the fastest airplanes.
All models will be timed from a
standing start and for seven laps on the
fly. Awards suitable for framing will be
presented for both methods. The survey
on the Speed forum showed 18 for Proto
time and 15 for standard, so we will do
both. NASS will supply watches, contest
equipment, and awards. The contestants
will supply timers.
The regulations are as follows:
1) Models with .15 size engines max
(.1525).
2) Models must use two (2) lines sized
.014- x 60-feet plus all you want, minus 6
inches.
3) Times of models flown on 59-foot
6-inch lines will be adjusted to 60 feet
with a correction factor.
4) All models must have at least one
(1) wheel.
5) No asymmetric models allowed.
6) Models may be whipped for takeoff
only. When the wheel leaves the
ground the arm stops!
7) Hamsters, Goodyear racers, and
any model with a .15 on the nose
including purpose-built are welcome to
compete as long as they meet the above
criteria.
8) One-and-a-half laps are allowed to
enter the pylon.
9) Open-face exhaust or mini pipe
allowed. No tuned pipes.
10) Fuel of 10% nitro will be supplied
by contest management.
11) No one-blade propellers allowed.
The rules are subject to change until
the day of the contest with the intent of
obtaining maximum participation.
A few of the rules created a high level
of discussion. Rule 2 reflects the practice
of making lines 6 inches shorter than 60
feet, as is allowed by the rules for racing
and is used by all of the racers. They time
the flight based on 60-foot lines and
ignore the fact that the lines are shorter
than that. I don’t know how or why this
practice developed in the racing
community.
This practice of using short lines is the
reason for Rule 3: the correction factor to
bring the times back to a full 60-foot
length. This did generate a few offers by
Speed fliers to hold classes on the use of
measuring tapes and line construction!
The next item to cause discussion was
Rule 7, which specifically allows the use
July 2004 147
SG Model Engines
P.O. Box 280303
Northridge, CA 91328
Tel. (818) 472-8460
Engines, Accessories & Parts
Dealers
Welcome
Web Site: Shop.vendio.com/RossiEnginesUSA
WWW.PSPEC.COM
Complete engine and muffler packages are available.
VISIT US AT WWW.PSPEC.COM.
DEALER INQUIRIES WELCOME!
TWISTER 4-STROKE MUFFLERS & ELBOWS
PISTON/CYLINDER ASSEMBLIES
ULTRATHRUST MUFFLERS
PERFORMANCE SPECIALTIES
PO Box 3146 • Gardnerville, NV 89410
Phone: 775-265-7523 • Fax: 775-265-7522
of purpose-built models. This was
included in an attempt to invite Speed
fliers to put together a model for the
Hamster Dash.
The rule caused a few of the racers to
state that they would not stand a chance
against models designed for the event.
They felt that the 2-ounce tanks and
shutoff units would add weight that would
hold their speeds down. Some felt that the
larger wing and stabilizer area would
work against them.
Let’s look at these concerns beginning
with the wing-area issue. The average
Hamster has a wingspan between 22 and
24 inches and has a working elevator
across the full length of the stabilizer. The
large elevator is used to shake off speed
to make landings happen quicker in the
racing environment.
This should not present a problem in a
Speed run. Racing pilots are able to
groove these models in the traffic of a
race, so they will surely not find it
difficult to groove during a Speed run of
14 laps.
The wingspan is comparable to that
used in the Formula 40 event. Many
Speed models flown today use wing areas
much larger than those used in the past.
The increased wing area produces a
model that flies more smoothly, and it is
07sig5.QXD 4/23/04 10:08 am Page 147
much easier to land than the small models
of the past which simply dropped out of
the air when the engine quit.
The issue of model weight caused the
highest level of concern among the racers.
It was often stated that the lighter weight
of purpose-built models would give them
such a significant edge that it would make
the Rat Racers noncompetitive. After
reviewing last year’s Nats results, I
disagree.
The Hamster Dash will have two
timing components: the standing-start
mile and the on-the-fly 1⁄2 mile; in effect,
we have two separate events in one.
The standing-start one-mile timing will
probably go to a purpose-built model, or
as we will call it, a Formula 15. This
statement is based on reviewing the model
weights of the first three places in
Formula 40 and 1⁄2A Proto.
In Formula 40, first, second, and third
places went to models that weighed 23-28
ounces including fuel. One other model
fell within this range but didn’t place. The
rest entered in the event were heavier.
In 1⁄2A Proto, the first five places went to
models that ranged from 4.9 to 6.3 ounces
including fuel. There are two anomalies in
this group. The 6.3-ounce model came in
second and the 4.9-ounce model came in
fifth. The other three placing models
weighed 5.5, 5.1, and 5.6 ounces. I
conclude that lighter is much better in an
event where acceleration is a component.
Weight does not appear to be as
important in the events timed on-the-fly
that are not piped. In .21, sport models
ranged from 18.5 to 25 ounces. First place
went to a 22-ounce unit and second
through fifth places went to models
ranging between 22 and 25 ounces.
In D Speed, first- through fifth-place
entries weighed 43, 46, 40, 38, and 42
ounces respectively. I see no clear-cut
pattern here indicating that lighter is
totally necessary to place in a Speed
event, but Paul Gibeault, a NASS member
from Alberta, Canada, summed the issue
up with the statement, “A heavy-flying
Speed model is far superior to the lightest
Speed model that never sees a contest!”
Lighter is better in Speed models, but
this can be carried to extremes. I have
seen a few airplanes that were constructed
so light that they did not last one flight.
One thing that helps reduce weight is
to use a little magnesium Speed pan. It is
common on Formula 40 models to use a
DARP ([734] 266-7290) B Pan cut to 101⁄2
inches. This should be replaced with a
DARP Proto Pan cut to 51⁄4 inches long.
The width is narrowed to the same as the
B Pan. The Proto Pan allows the use of all
six hold-down screws on the Nelson .40.
The area that was pan is replaced with
a piece of 1⁄16 basswood that has been
soaked in water and wrapped over the end
of the pan that was cut off and left to dry.
This item is much lighter than a hollowedout
balsa block and much stronger.
The pan is hollowed out and thinned to
a thickness of .080 inch. It can be difficult
to measure the thickness of the pan. If you
have a drill press, set a small drill so that
it stops at roughly .080 inch to .100 inch
above the table. Drill the pan in the areas
that you plan to thin. Install a rotary file in
the chuck, and work the pan down to the
drill points and stop.
This method gives you a target area of
how far to take the thinning. The fins on
the Nelson should be milled down to 11⁄2
inches diameter. The propeller nut is
replaced with a nut made from 7075
aluminum.
The landing-gear strut should be
titanium, which can be obtained from
Glenn Lee ([630] 879-2558). Order a set
of Glenn’s 1-inch-diameter wheels. The
wheels come with brass hubs which
should be replaced with ones made from
aluminum.
This attention to detail should be
applied to every item in the model. The
result is a Formula 40 with a weight—
including fuel—of 21.5 ounces. The
results of the test flights will be in the next
column.
I am out of space for this time. I’ll be
back in three months. MA
148 MODEL AVIATION
07sig5.QXD 4/23/04 10:08 am Page 148
Edition: Model Aviation - 2004/07
Page Numbers: 146,147,148
146 MODEL AVIATION
THIS MONTH I will write about the
inaugural Hamster Dash at the 2004
Nats, the effect of model weight, and a
few methods of building a lightweight
Speedster.
Following the demise of .40-powered
Rat Racers, the racing community has
been looking for an event to replace it.
In 2002, the participants tried a .21-
powered racer. This size of power plant
is not a displacement that CL racers
have in their engine sheds. Not many
models powered with .21s were built.
The next size tried was a .15-
powered Rat Racer. This size caught on
because it is a displacement used in
other racing events. Racers
affectionately refer to the models used in
.15 Rat as “Hamsters.”
The North American Speed Society
(NASS) will hold the first Hamster Dash
on Tuesday, July 13, 2004, during the
Nats. It will be at the Speed site at the
CONTROL LINE SPEED
Dave Mark, Box 371, Fenton MI 48430; E-mail: [email protected]
Bill Hughes is holding his 1⁄2A Proto aircraft and his soon-to-bekitted
1⁄2A Speed model.
Ron Salo flies in the pylon at the 2002 Control Line World
Championships held in Sebnitz, Germany.
Len Waltemath, center, is the Jet record holder at 204.93 mph. Pilot Joey Mathison (L)
and pit crew Arlyn Valentine are shown with him.
07sig5.QXD 4/23/04 10:08 am Page 146
International Aeromodeling Center in
Muncie, Indiana, and will begin
following the completion of the day’s
scheduled events.
This unofficial event is the result of
much discussion on the Delphi Speed
Forum. Racers were asking if it would be
possible to use the Speed circles and
pylons to test their models. NASS then
made an offer to host the festivities and
supply awards for the fastest airplanes.
All models will be timed from a
standing start and for seven laps on the
fly. Awards suitable for framing will be
presented for both methods. The survey
on the Speed forum showed 18 for Proto
time and 15 for standard, so we will do
both. NASS will supply watches, contest
equipment, and awards. The contestants
will supply timers.
The regulations are as follows:
1) Models with .15 size engines max
(.1525).
2) Models must use two (2) lines sized
.014- x 60-feet plus all you want, minus 6
inches.
3) Times of models flown on 59-foot
6-inch lines will be adjusted to 60 feet
with a correction factor.
4) All models must have at least one
(1) wheel.
5) No asymmetric models allowed.
6) Models may be whipped for takeoff
only. When the wheel leaves the
ground the arm stops!
7) Hamsters, Goodyear racers, and
any model with a .15 on the nose
including purpose-built are welcome to
compete as long as they meet the above
criteria.
8) One-and-a-half laps are allowed to
enter the pylon.
9) Open-face exhaust or mini pipe
allowed. No tuned pipes.
10) Fuel of 10% nitro will be supplied
by contest management.
11) No one-blade propellers allowed.
The rules are subject to change until
the day of the contest with the intent of
obtaining maximum participation.
A few of the rules created a high level
of discussion. Rule 2 reflects the practice
of making lines 6 inches shorter than 60
feet, as is allowed by the rules for racing
and is used by all of the racers. They time
the flight based on 60-foot lines and
ignore the fact that the lines are shorter
than that. I don’t know how or why this
practice developed in the racing
community.
This practice of using short lines is the
reason for Rule 3: the correction factor to
bring the times back to a full 60-foot
length. This did generate a few offers by
Speed fliers to hold classes on the use of
measuring tapes and line construction!
The next item to cause discussion was
Rule 7, which specifically allows the use
July 2004 147
SG Model Engines
P.O. Box 280303
Northridge, CA 91328
Tel. (818) 472-8460
Engines, Accessories & Parts
Dealers
Welcome
Web Site: Shop.vendio.com/RossiEnginesUSA
WWW.PSPEC.COM
Complete engine and muffler packages are available.
VISIT US AT WWW.PSPEC.COM.
DEALER INQUIRIES WELCOME!
TWISTER 4-STROKE MUFFLERS & ELBOWS
PISTON/CYLINDER ASSEMBLIES
ULTRATHRUST MUFFLERS
PERFORMANCE SPECIALTIES
PO Box 3146 • Gardnerville, NV 89410
Phone: 775-265-7523 • Fax: 775-265-7522
of purpose-built models. This was
included in an attempt to invite Speed
fliers to put together a model for the
Hamster Dash.
The rule caused a few of the racers to
state that they would not stand a chance
against models designed for the event.
They felt that the 2-ounce tanks and
shutoff units would add weight that would
hold their speeds down. Some felt that the
larger wing and stabilizer area would
work against them.
Let’s look at these concerns beginning
with the wing-area issue. The average
Hamster has a wingspan between 22 and
24 inches and has a working elevator
across the full length of the stabilizer. The
large elevator is used to shake off speed
to make landings happen quicker in the
racing environment.
This should not present a problem in a
Speed run. Racing pilots are able to
groove these models in the traffic of a
race, so they will surely not find it
difficult to groove during a Speed run of
14 laps.
The wingspan is comparable to that
used in the Formula 40 event. Many
Speed models flown today use wing areas
much larger than those used in the past.
The increased wing area produces a
model that flies more smoothly, and it is
07sig5.QXD 4/23/04 10:08 am Page 147
much easier to land than the small models
of the past which simply dropped out of
the air when the engine quit.
The issue of model weight caused the
highest level of concern among the racers.
It was often stated that the lighter weight
of purpose-built models would give them
such a significant edge that it would make
the Rat Racers noncompetitive. After
reviewing last year’s Nats results, I
disagree.
The Hamster Dash will have two
timing components: the standing-start
mile and the on-the-fly 1⁄2 mile; in effect,
we have two separate events in one.
The standing-start one-mile timing will
probably go to a purpose-built model, or
as we will call it, a Formula 15. This
statement is based on reviewing the model
weights of the first three places in
Formula 40 and 1⁄2A Proto.
In Formula 40, first, second, and third
places went to models that weighed 23-28
ounces including fuel. One other model
fell within this range but didn’t place. The
rest entered in the event were heavier.
In 1⁄2A Proto, the first five places went to
models that ranged from 4.9 to 6.3 ounces
including fuel. There are two anomalies in
this group. The 6.3-ounce model came in
second and the 4.9-ounce model came in
fifth. The other three placing models
weighed 5.5, 5.1, and 5.6 ounces. I
conclude that lighter is much better in an
event where acceleration is a component.
Weight does not appear to be as
important in the events timed on-the-fly
that are not piped. In .21, sport models
ranged from 18.5 to 25 ounces. First place
went to a 22-ounce unit and second
through fifth places went to models
ranging between 22 and 25 ounces.
In D Speed, first- through fifth-place
entries weighed 43, 46, 40, 38, and 42
ounces respectively. I see no clear-cut
pattern here indicating that lighter is
totally necessary to place in a Speed
event, but Paul Gibeault, a NASS member
from Alberta, Canada, summed the issue
up with the statement, “A heavy-flying
Speed model is far superior to the lightest
Speed model that never sees a contest!”
Lighter is better in Speed models, but
this can be carried to extremes. I have
seen a few airplanes that were constructed
so light that they did not last one flight.
One thing that helps reduce weight is
to use a little magnesium Speed pan. It is
common on Formula 40 models to use a
DARP ([734] 266-7290) B Pan cut to 101⁄2
inches. This should be replaced with a
DARP Proto Pan cut to 51⁄4 inches long.
The width is narrowed to the same as the
B Pan. The Proto Pan allows the use of all
six hold-down screws on the Nelson .40.
The area that was pan is replaced with
a piece of 1⁄16 basswood that has been
soaked in water and wrapped over the end
of the pan that was cut off and left to dry.
This item is much lighter than a hollowedout
balsa block and much stronger.
The pan is hollowed out and thinned to
a thickness of .080 inch. It can be difficult
to measure the thickness of the pan. If you
have a drill press, set a small drill so that
it stops at roughly .080 inch to .100 inch
above the table. Drill the pan in the areas
that you plan to thin. Install a rotary file in
the chuck, and work the pan down to the
drill points and stop.
This method gives you a target area of
how far to take the thinning. The fins on
the Nelson should be milled down to 11⁄2
inches diameter. The propeller nut is
replaced with a nut made from 7075
aluminum.
The landing-gear strut should be
titanium, which can be obtained from
Glenn Lee ([630] 879-2558). Order a set
of Glenn’s 1-inch-diameter wheels. The
wheels come with brass hubs which
should be replaced with ones made from
aluminum.
This attention to detail should be
applied to every item in the model. The
result is a Formula 40 with a weight—
including fuel—of 21.5 ounces. The
results of the test flights will be in the next
column.
I am out of space for this time. I’ll be
back in three months. MA
148 MODEL AVIATION
07sig5.QXD 4/23/04 10:08 am Page 148