September 2011 55
GO FAST and turn left is a phrase you will hear every
once in a while, especially if you hang around Pylon racers.
Have you ever watched a Pylon race and thought, “That
looks like a lot of fun?” Well the new E-flite Shoestring
might be the airplane that lets you see how fun it can be.
In 2009, discussions began to start an electric-powered
scale racing class: Electric Formula One (EF1). It was
developed as an inexpensive, entry-level event that uses
readily available ARFs. The hope is that it will appeal to
pilots at a grass-roots level.
The airplanes are designed so that they can be flown for
sport during the week and raced on the weekend. The goal
is to bring in new racers ranging from new to experienced
pilots.
The aircraft are based on Scale Formula 1 racers with
375 square inches of wing area. The target speed is in the
110-120 mph range using components available at the local
hobby store. With a few power equipment changes, you
could easily push the speeds to 135-140 mph. These
changes are not allowed under the current EF1 rules, but I
could see, assuming the class takes off as hoped, a second
“professional” EF1 class being created to allow them.
Construction: In typical E-flite fashion, the Shoestring
ARF is a very complete kit. Short
of a little epoxy, CA, a few tools,
and some very minor
miscellaneous items, you’ll find
everything needed in the box.
When you first open the box
you see the care E-flite has taken
with this kit. Each part is
wrapped and packed in its own
spot in the box, sectioned off
with cardboard. Upon inspecting the parts that were
included, I discovered a very complete hardware kit which
included two different length engine standoffs, precut and
prebent aileron pushrods, all bolts (metric) and screws
needed, and control horns.
As is typical with most sport airplanes of this size, CAtype
hinges are used to attach the control surfaces. They
were all installed (but not glued) in precut slots. All of the
pushrods have been cut to length and have the Z-bends
completed.
The elevator and rudder pushrods have even been
installed into the fuselage. E-flite has predrilled all the
control horn holes into the control surfaces. The wheel
pants have been precut and drilled, too. They are also
formed with an indention for the landing gear to sit in,
making them very secure. The fiberglass cowling is wellconstructed
and follows the contours of the airframe nicely.
As of the date of my review, the instruction manual was
still being written, but if you have any ARF assembly
experience at all, it really isn’t necessary. E-flite has done g
The E-flite Shoestring ARF 15e EF1 is a versatile aircraft,
designed to be flown for sport or Pylon racing.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:09 AM Page 55
E-flite installed a slot in the fuselage for the
speed control. Its position allows the cooling
air to be directed over the speed control.
Although it’s considered a “smaller”
model, there is plenty of room inside
for your radio equipment and battery.
The motor box is quite long, but it is sturdy
and resists twisting from the torque of the
motor.
everything possible to make the building process as simple
and as quick as possible.
The first step I took was to epoxy on the horizontal and
vertical stabilizer. I measured to find the center of the
horizontal stabilizer and fuselage and used these marks as
my initial reference to set the stabilizer.
Once I had the marks lined up, I double-checked that it
was centered from side to side. I also measured from the tip
of the stabilizer to the tip of the tail to ensure that it was
installed square with the fuselage. When I was happy with
the fit, I marked and cut away the covering so that I would
have a good wood-to-wood joint.
Make sure the stabilizer is as far forward in the slot as
possible, because the elevators are attached to one another
with a prebent piece of piano wire that needs to fit down in
the cut-out part of the fuselage. After that had set up for a
little bit (I used 5-minute epoxy), I attached the vertical
stabilizer. This was simple because the stabilizer and filler
block are all one piece. All I had to do was line it up and
glue it down.
Don’t forget to cut the covering away on the horizontal
stabilizer to make sure you have a good joint. Don’t
forget to put the elevator connecting rod in before you
glue it down; I almost got caught on this.
Use a little tape to hold everything down and tight while
the epoxy cures. While waiting for the epoxy to cure, I
started working on the wings. This kit uses an aileron servo
in each wing, which is recessed into the wing under
preconstructed hatches; even the blocks to attach the servos
to are preinstalled. I did have to do a little trimming on these
tabs because they are designed around the JR 368 servo
which is a smaller servo than the JR Sport MN48 servos that
I used.
The airfoil is fairly thin so I shifted the servos toward the
LE to ensure that I would have room for the servo. After I
had the servos installed and centered, and the servo arms
installed, I fed the wire through the wing with the prerun
string and screwed the hatches down.
Depending on the length of the servo lead, you may need
to add an extension to get the wire all the way out of the
wing (I used a 6-inch extension in each wing).
As I stated earlier, CA-type hinges are used and all of the
slots are precut. I did have to cut the covering away for the
bottom hinge on the rudder. During this process, I had to
laugh. Thanks to the predrilled control horn holes, I
discovered that I had installed the horizontal stabilizer
56 MODEL AVIATION
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:10 AM Page 56
Elevators are held on with three CA hinges and connected
to each other with a prebent piece of piano wire.
+
• Level of completeness out of the box
• Can be raced or flown as a sport flyer
• Easy wing attachment
• Secure hatch provides quick battery
access -•
E-flite Power 25 provides a lot
of torque
Pluses and Min uses
Test Model Details
Power: E-flite Power 25 (1,250kV)
outrunner motor, 60 amp ESC
Battery: E-flite four-cell, 2,500 mAh
Li-Poly
Propeller: APC 10 x 7E or APC 8 x 8E
for racing
Radio system: JR X9303 transmitter,
Spektrum AR6210 DSM2 receiver,
four JR Sport MN-48 servos, two
6-inch servo extensions
Ready-to-fly weight: 3.25 pounds
Flight duration: 7-10 minutes,
4 minutes for racing
Specifications
Model type: RC Sport
Skill level: Beginner builder;
intermediate pilot
Wingspan: 48 inches
Wing area: 378 square inches
Length: 33 inches
Weight: 3.25 pounds
Wing loading: 19.81 ounces/square
foot
Power system: 600-850 watts
Radio: Four channels with four servos
Construction: Balsa and light plywood
Price: $149.99
upside down. Fortunately, this is a flat surface so it had no ill effect on
the airplane.
To complete the installation of the control surfaces, only two more
steps are necessary. You need to mount the control horns, which is made
easy by the predrilled holes. The next step is to hook up the pushrods,
again simplified because they are precut and installed for you.
The only things I added that weren’t included in the kit were small
pieces of fuel tubing to prevent the clevis from opening during flight. I
put the tail servos in the precut spot, centered them, and hooked up the
pushrods.
At this point, all of the control surfaces have been installed and
hooked up to the radio gear, so I moved on to the power plant and speed
control installation. This was incredibly simple because E-flite had the
forethought to install a slot in the fuselage for the speed control. The
only difficult part of this was getting the Velcro strap around it and
tight enough to keep it in place.
I then bolted on the motor, routed the wiring, and hooked it up to the
speed control.
Tip: for the E-flite Power 25 motor, you will want to use the short
stand-offs included in the kit. I also added a washer to give myself a
little more clearance between the cowling and spinner. Finally, I
installed the AR6210 receiver in front of the tail surface servos and the
satellite receiver toward the front of the airplane on the left side with
some Velcro.
The last step was the installation of the landing gear, wheels, and
wheel pants. The hardest part was cutting out the landing gear cuffs
from the vacuum-formed plastic; however, there are indentions molded
in to show you where to cut.
I installed the landing gear, slid the cuffs over them, and taped them
down with clear tape. This essentially completed the fuselage around
the landing gear. The wheels and wheel pants were again made easy
thanks to the forethought of E-flite.
E-flite provides a complete kit including
an extensive hardware package.
September 2011 57
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:11 AM Page 57
58 MODEL AVIATION
Flying: As I stated at the beginning of the article, the
Shoestring was designed to be a nice, easy sport flyer that can
be turned into a Pylon racer by simply adjusting the rates on
the control surfaces and putting on a different propeller. Eflite
has done an exceptional job of completing this objective.
Since I began Pylon racing approximately two years ago,
it is the only type of flying I do. Because of this I decided to
test that side of the model first.
As I mentioned earlier, EF1 is a new class of Pylon racing
that is being developed to entice additional pilots into the
racing world. It is designed to be an entry-level class that any
and all can enjoy. It’s flown on a 375-foot, three-pylon course
or a 400-foot, two-pylon course, which allows it to be flown
almost anywhere, including at some of the tightest fields.
Additionally, the model type, motor, and batteries are
going to be limited and must go through an approval process
to keep the playing field level. You can get more details of
the rules at RCGroups in a forum titled “Electric Formula
One: List of Recommended and Approved Components,”
and, of course, on the National Miniature Pylon Racing
Association (NMPRA) website.
The original design of the full-scale Shoestring was for air
racing, and this can be seen in the model’s speed and flight
characteristics. Although it was only flying slightly more than
100 mph, it felt much faster because of the shorter course. It
tracked straight and true through the corners with no need for
rudder input.
As it exited the turn and I let off of the elevator, it would
stop turning and track straight ahead toward the next turn,
waiting anxiously for me to tell it what to do next. I typically
like to keep my racer at roughly a 45° knife-edge as I’m
heading to the next pylon because it requires less aileron
input to get ready for the turn. However, I had to “flatten”
the Shoestring out slightly more because it felt like it was
slipping out of the sky toward the end of the straightaway.
Another characteristic of a good racer is minimal speed
loss in the turns, and the Shoestring appeared to possess this
quality. I was told to expect approximately 4 minutes of
flight time at full throttle so I set my timer at 3 minutes.
When it beeped I began my landing approach.
To my surprise, the airplane had no slow-flight bad
habits. It does take a longer approach, and because it’s
designed for racing, the airframe doesn’t create much drag.
As such, it takes some time to bleed off speed.
I had two batteries left so I took it up for two more flights
to make sure my initial assessment was accurate. I’m happy
to report that the Shoestring performed well flight after
flight.
The Shoestring flies so well it is relaxing to fly it. Opposite
aileron and down-elevator were needed to track straight in
knife-edge flight.
Photos by the author
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:12 AM Page 58
September 2011 59
Sport Flying: Since I had used up all the batteries I had on
the pylon flights, I had to come home and charge them and
test the airplane’s sport-flying ability on another day.
Unfortunately, the day I chose had wind speeds of
approximately 10-15 mph. To my surprise the Shoestring
took the wind and asked, “What else you got?”
It got bumped around, but it was easy to keep on track and
I felt comfortable having it a few feet off the deck, even
inverted. With the control rates turned up, it handled all of the
scale aerobatics with ease. Although I didn’t try it before to
writing the review, I have confidence that the control surfaces
are large enough to do some basic 3-D aerobatics.
Conclusion: If you have thought to yourself, “I’d like to get
into Pylon racing but I don’t want to buy an airplane just for
that,” then the Shoestring and the new EF1 class are for you.
Although the Shoestring was designed for racing, E-flite has
done a great job of making it a sport model that can be raced,
or if you prefer, a racing airplane that can be sport flown. MA
Manufacturer/Distributor:
E-flite/Horizon Hobby
4105 Fieldstone Rd.
Champaign, IL 61822
(800) 338-4639
www.e-fliterc.com
www.horizonhobby.com
Sources:
JR Radio
(877) 504-0233
www.jrradios.com
Spektrum RC
(800) 338-4639
www.spektrumrc.com
APC Propellers
(530) 661-0399
www.apcprop.com
RCGroups
www.rcgroups.com
NMPRA
www.NMPRA.org
On Saturday morning, July 9, the 2011
AMA Nationals Pylon Racing event wrapped
up with an Electric Formula One (EF1)
contest. The 43 airplanes entered in the event
were primarily E-flite LR-1A Pogos and
Shoestrings, along with a few other
prototypes and kit-built models to round out
the field.
Horizon Hobby/E-flite sponsored the
event and gave every entrant a nice pilot’s
package. Pete Bergstrom announced that Eflite
was going to release the Shoestring 15e
EF1 Racer in roughly mid-October.
I was able to get some practice time on
Thursday and Friday which allowed me to
fine-tune my throws and trim on the airplane.
The Shoestring was flying well because of the
flight characteristics of the airplane, and I was
feeling reasonably confident.
I managed to place first and third in my
first two rounds of competition. In my third
round, I was trying to get the jump on Travis
Flynn and ended up running into Pylon Two,
putting an early end to the Shoestring’s racing
career. This unfortunate occurrence happens
in racing.
The Shoestring 15e EF1 Racer was a very
competitive airplane that was easy to fly and
take off, even with downwind takeoffs. It
didn’t take nearly the amount of controls
some of the other pilots mentioned their
models needed. It simply took the commands
I gave it and asked, “What’s next?”
The Shoestring fits the intent of this class
perfectly. It is a great weekday sport flyer that
can be turned into a competitive race airplane
with some simple control surface-rate
changes and installing the APC 8 x 8E
propeller.
I plan to get a new one in October when
they come out. MA
—Lonnie Finch
Horizon Hobby/E-flite sponsored
the Electric Formula One (EF1) contest
The E-flite Shoestring ARF is
designed to be flown for sport or
Pylon racing. It looks anxious to
fly just sitting on the runway.
Although easy enough to operate
one-handed, the hatch is very secure.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:14 AM Page 59
Edition: Model Aviation - 2011/09
Page Numbers: 54,55,56,57,58,59
Edition: Model Aviation - 2011/09
Page Numbers: 54,55,56,57,58,59
September 2011 55
GO FAST and turn left is a phrase you will hear every
once in a while, especially if you hang around Pylon racers.
Have you ever watched a Pylon race and thought, “That
looks like a lot of fun?” Well the new E-flite Shoestring
might be the airplane that lets you see how fun it can be.
In 2009, discussions began to start an electric-powered
scale racing class: Electric Formula One (EF1). It was
developed as an inexpensive, entry-level event that uses
readily available ARFs. The hope is that it will appeal to
pilots at a grass-roots level.
The airplanes are designed so that they can be flown for
sport during the week and raced on the weekend. The goal
is to bring in new racers ranging from new to experienced
pilots.
The aircraft are based on Scale Formula 1 racers with
375 square inches of wing area. The target speed is in the
110-120 mph range using components available at the local
hobby store. With a few power equipment changes, you
could easily push the speeds to 135-140 mph. These
changes are not allowed under the current EF1 rules, but I
could see, assuming the class takes off as hoped, a second
“professional” EF1 class being created to allow them.
Construction: In typical E-flite fashion, the Shoestring
ARF is a very complete kit. Short
of a little epoxy, CA, a few tools,
and some very minor
miscellaneous items, you’ll find
everything needed in the box.
When you first open the box
you see the care E-flite has taken
with this kit. Each part is
wrapped and packed in its own
spot in the box, sectioned off
with cardboard. Upon inspecting the parts that were
included, I discovered a very complete hardware kit which
included two different length engine standoffs, precut and
prebent aileron pushrods, all bolts (metric) and screws
needed, and control horns.
As is typical with most sport airplanes of this size, CAtype
hinges are used to attach the control surfaces. They
were all installed (but not glued) in precut slots. All of the
pushrods have been cut to length and have the Z-bends
completed.
The elevator and rudder pushrods have even been
installed into the fuselage. E-flite has predrilled all the
control horn holes into the control surfaces. The wheel
pants have been precut and drilled, too. They are also
formed with an indention for the landing gear to sit in,
making them very secure. The fiberglass cowling is wellconstructed
and follows the contours of the airframe nicely.
As of the date of my review, the instruction manual was
still being written, but if you have any ARF assembly
experience at all, it really isn’t necessary. E-flite has done g
The E-flite Shoestring ARF 15e EF1 is a versatile aircraft,
designed to be flown for sport or Pylon racing.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:09 AM Page 55
E-flite installed a slot in the fuselage for the
speed control. Its position allows the cooling
air to be directed over the speed control.
Although it’s considered a “smaller”
model, there is plenty of room inside
for your radio equipment and battery.
The motor box is quite long, but it is sturdy
and resists twisting from the torque of the
motor.
everything possible to make the building process as simple
and as quick as possible.
The first step I took was to epoxy on the horizontal and
vertical stabilizer. I measured to find the center of the
horizontal stabilizer and fuselage and used these marks as
my initial reference to set the stabilizer.
Once I had the marks lined up, I double-checked that it
was centered from side to side. I also measured from the tip
of the stabilizer to the tip of the tail to ensure that it was
installed square with the fuselage. When I was happy with
the fit, I marked and cut away the covering so that I would
have a good wood-to-wood joint.
Make sure the stabilizer is as far forward in the slot as
possible, because the elevators are attached to one another
with a prebent piece of piano wire that needs to fit down in
the cut-out part of the fuselage. After that had set up for a
little bit (I used 5-minute epoxy), I attached the vertical
stabilizer. This was simple because the stabilizer and filler
block are all one piece. All I had to do was line it up and
glue it down.
Don’t forget to cut the covering away on the horizontal
stabilizer to make sure you have a good joint. Don’t
forget to put the elevator connecting rod in before you
glue it down; I almost got caught on this.
Use a little tape to hold everything down and tight while
the epoxy cures. While waiting for the epoxy to cure, I
started working on the wings. This kit uses an aileron servo
in each wing, which is recessed into the wing under
preconstructed hatches; even the blocks to attach the servos
to are preinstalled. I did have to do a little trimming on these
tabs because they are designed around the JR 368 servo
which is a smaller servo than the JR Sport MN48 servos that
I used.
The airfoil is fairly thin so I shifted the servos toward the
LE to ensure that I would have room for the servo. After I
had the servos installed and centered, and the servo arms
installed, I fed the wire through the wing with the prerun
string and screwed the hatches down.
Depending on the length of the servo lead, you may need
to add an extension to get the wire all the way out of the
wing (I used a 6-inch extension in each wing).
As I stated earlier, CA-type hinges are used and all of the
slots are precut. I did have to cut the covering away for the
bottom hinge on the rudder. During this process, I had to
laugh. Thanks to the predrilled control horn holes, I
discovered that I had installed the horizontal stabilizer
56 MODEL AVIATION
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:10 AM Page 56
Elevators are held on with three CA hinges and connected
to each other with a prebent piece of piano wire.
+
• Level of completeness out of the box
• Can be raced or flown as a sport flyer
• Easy wing attachment
• Secure hatch provides quick battery
access -•
E-flite Power 25 provides a lot
of torque
Pluses and Min uses
Test Model Details
Power: E-flite Power 25 (1,250kV)
outrunner motor, 60 amp ESC
Battery: E-flite four-cell, 2,500 mAh
Li-Poly
Propeller: APC 10 x 7E or APC 8 x 8E
for racing
Radio system: JR X9303 transmitter,
Spektrum AR6210 DSM2 receiver,
four JR Sport MN-48 servos, two
6-inch servo extensions
Ready-to-fly weight: 3.25 pounds
Flight duration: 7-10 minutes,
4 minutes for racing
Specifications
Model type: RC Sport
Skill level: Beginner builder;
intermediate pilot
Wingspan: 48 inches
Wing area: 378 square inches
Length: 33 inches
Weight: 3.25 pounds
Wing loading: 19.81 ounces/square
foot
Power system: 600-850 watts
Radio: Four channels with four servos
Construction: Balsa and light plywood
Price: $149.99
upside down. Fortunately, this is a flat surface so it had no ill effect on
the airplane.
To complete the installation of the control surfaces, only two more
steps are necessary. You need to mount the control horns, which is made
easy by the predrilled holes. The next step is to hook up the pushrods,
again simplified because they are precut and installed for you.
The only things I added that weren’t included in the kit were small
pieces of fuel tubing to prevent the clevis from opening during flight. I
put the tail servos in the precut spot, centered them, and hooked up the
pushrods.
At this point, all of the control surfaces have been installed and
hooked up to the radio gear, so I moved on to the power plant and speed
control installation. This was incredibly simple because E-flite had the
forethought to install a slot in the fuselage for the speed control. The
only difficult part of this was getting the Velcro strap around it and
tight enough to keep it in place.
I then bolted on the motor, routed the wiring, and hooked it up to the
speed control.
Tip: for the E-flite Power 25 motor, you will want to use the short
stand-offs included in the kit. I also added a washer to give myself a
little more clearance between the cowling and spinner. Finally, I
installed the AR6210 receiver in front of the tail surface servos and the
satellite receiver toward the front of the airplane on the left side with
some Velcro.
The last step was the installation of the landing gear, wheels, and
wheel pants. The hardest part was cutting out the landing gear cuffs
from the vacuum-formed plastic; however, there are indentions molded
in to show you where to cut.
I installed the landing gear, slid the cuffs over them, and taped them
down with clear tape. This essentially completed the fuselage around
the landing gear. The wheels and wheel pants were again made easy
thanks to the forethought of E-flite.
E-flite provides a complete kit including
an extensive hardware package.
September 2011 57
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:11 AM Page 57
58 MODEL AVIATION
Flying: As I stated at the beginning of the article, the
Shoestring was designed to be a nice, easy sport flyer that can
be turned into a Pylon racer by simply adjusting the rates on
the control surfaces and putting on a different propeller. Eflite
has done an exceptional job of completing this objective.
Since I began Pylon racing approximately two years ago,
it is the only type of flying I do. Because of this I decided to
test that side of the model first.
As I mentioned earlier, EF1 is a new class of Pylon racing
that is being developed to entice additional pilots into the
racing world. It is designed to be an entry-level class that any
and all can enjoy. It’s flown on a 375-foot, three-pylon course
or a 400-foot, two-pylon course, which allows it to be flown
almost anywhere, including at some of the tightest fields.
Additionally, the model type, motor, and batteries are
going to be limited and must go through an approval process
to keep the playing field level. You can get more details of
the rules at RCGroups in a forum titled “Electric Formula
One: List of Recommended and Approved Components,”
and, of course, on the National Miniature Pylon Racing
Association (NMPRA) website.
The original design of the full-scale Shoestring was for air
racing, and this can be seen in the model’s speed and flight
characteristics. Although it was only flying slightly more than
100 mph, it felt much faster because of the shorter course. It
tracked straight and true through the corners with no need for
rudder input.
As it exited the turn and I let off of the elevator, it would
stop turning and track straight ahead toward the next turn,
waiting anxiously for me to tell it what to do next. I typically
like to keep my racer at roughly a 45° knife-edge as I’m
heading to the next pylon because it requires less aileron
input to get ready for the turn. However, I had to “flatten”
the Shoestring out slightly more because it felt like it was
slipping out of the sky toward the end of the straightaway.
Another characteristic of a good racer is minimal speed
loss in the turns, and the Shoestring appeared to possess this
quality. I was told to expect approximately 4 minutes of
flight time at full throttle so I set my timer at 3 minutes.
When it beeped I began my landing approach.
To my surprise, the airplane had no slow-flight bad
habits. It does take a longer approach, and because it’s
designed for racing, the airframe doesn’t create much drag.
As such, it takes some time to bleed off speed.
I had two batteries left so I took it up for two more flights
to make sure my initial assessment was accurate. I’m happy
to report that the Shoestring performed well flight after
flight.
The Shoestring flies so well it is relaxing to fly it. Opposite
aileron and down-elevator were needed to track straight in
knife-edge flight.
Photos by the author
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:12 AM Page 58
September 2011 59
Sport Flying: Since I had used up all the batteries I had on
the pylon flights, I had to come home and charge them and
test the airplane’s sport-flying ability on another day.
Unfortunately, the day I chose had wind speeds of
approximately 10-15 mph. To my surprise the Shoestring
took the wind and asked, “What else you got?”
It got bumped around, but it was easy to keep on track and
I felt comfortable having it a few feet off the deck, even
inverted. With the control rates turned up, it handled all of the
scale aerobatics with ease. Although I didn’t try it before to
writing the review, I have confidence that the control surfaces
are large enough to do some basic 3-D aerobatics.
Conclusion: If you have thought to yourself, “I’d like to get
into Pylon racing but I don’t want to buy an airplane just for
that,” then the Shoestring and the new EF1 class are for you.
Although the Shoestring was designed for racing, E-flite has
done a great job of making it a sport model that can be raced,
or if you prefer, a racing airplane that can be sport flown. MA
Manufacturer/Distributor:
E-flite/Horizon Hobby
4105 Fieldstone Rd.
Champaign, IL 61822
(800) 338-4639
www.e-fliterc.com
www.horizonhobby.com
Sources:
JR Radio
(877) 504-0233
www.jrradios.com
Spektrum RC
(800) 338-4639
www.spektrumrc.com
APC Propellers
(530) 661-0399
www.apcprop.com
RCGroups
www.rcgroups.com
NMPRA
www.NMPRA.org
On Saturday morning, July 9, the 2011
AMA Nationals Pylon Racing event wrapped
up with an Electric Formula One (EF1)
contest. The 43 airplanes entered in the event
were primarily E-flite LR-1A Pogos and
Shoestrings, along with a few other
prototypes and kit-built models to round out
the field.
Horizon Hobby/E-flite sponsored the
event and gave every entrant a nice pilot’s
package. Pete Bergstrom announced that Eflite
was going to release the Shoestring 15e
EF1 Racer in roughly mid-October.
I was able to get some practice time on
Thursday and Friday which allowed me to
fine-tune my throws and trim on the airplane.
The Shoestring was flying well because of the
flight characteristics of the airplane, and I was
feeling reasonably confident.
I managed to place first and third in my
first two rounds of competition. In my third
round, I was trying to get the jump on Travis
Flynn and ended up running into Pylon Two,
putting an early end to the Shoestring’s racing
career. This unfortunate occurrence happens
in racing.
The Shoestring 15e EF1 Racer was a very
competitive airplane that was easy to fly and
take off, even with downwind takeoffs. It
didn’t take nearly the amount of controls
some of the other pilots mentioned their
models needed. It simply took the commands
I gave it and asked, “What’s next?”
The Shoestring fits the intent of this class
perfectly. It is a great weekday sport flyer that
can be turned into a competitive race airplane
with some simple control surface-rate
changes and installing the APC 8 x 8E
propeller.
I plan to get a new one in October when
they come out. MA
—Lonnie Finch
Horizon Hobby/E-flite sponsored
the Electric Formula One (EF1) contest
The E-flite Shoestring ARF is
designed to be flown for sport or
Pylon racing. It looks anxious to
fly just sitting on the runway.
Although easy enough to operate
one-handed, the hatch is very secure.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:14 AM Page 59
Edition: Model Aviation - 2011/09
Page Numbers: 54,55,56,57,58,59
September 2011 55
GO FAST and turn left is a phrase you will hear every
once in a while, especially if you hang around Pylon racers.
Have you ever watched a Pylon race and thought, “That
looks like a lot of fun?” Well the new E-flite Shoestring
might be the airplane that lets you see how fun it can be.
In 2009, discussions began to start an electric-powered
scale racing class: Electric Formula One (EF1). It was
developed as an inexpensive, entry-level event that uses
readily available ARFs. The hope is that it will appeal to
pilots at a grass-roots level.
The airplanes are designed so that they can be flown for
sport during the week and raced on the weekend. The goal
is to bring in new racers ranging from new to experienced
pilots.
The aircraft are based on Scale Formula 1 racers with
375 square inches of wing area. The target speed is in the
110-120 mph range using components available at the local
hobby store. With a few power equipment changes, you
could easily push the speeds to 135-140 mph. These
changes are not allowed under the current EF1 rules, but I
could see, assuming the class takes off as hoped, a second
“professional” EF1 class being created to allow them.
Construction: In typical E-flite fashion, the Shoestring
ARF is a very complete kit. Short
of a little epoxy, CA, a few tools,
and some very minor
miscellaneous items, you’ll find
everything needed in the box.
When you first open the box
you see the care E-flite has taken
with this kit. Each part is
wrapped and packed in its own
spot in the box, sectioned off
with cardboard. Upon inspecting the parts that were
included, I discovered a very complete hardware kit which
included two different length engine standoffs, precut and
prebent aileron pushrods, all bolts (metric) and screws
needed, and control horns.
As is typical with most sport airplanes of this size, CAtype
hinges are used to attach the control surfaces. They
were all installed (but not glued) in precut slots. All of the
pushrods have been cut to length and have the Z-bends
completed.
The elevator and rudder pushrods have even been
installed into the fuselage. E-flite has predrilled all the
control horn holes into the control surfaces. The wheel
pants have been precut and drilled, too. They are also
formed with an indention for the landing gear to sit in,
making them very secure. The fiberglass cowling is wellconstructed
and follows the contours of the airframe nicely.
As of the date of my review, the instruction manual was
still being written, but if you have any ARF assembly
experience at all, it really isn’t necessary. E-flite has done g
The E-flite Shoestring ARF 15e EF1 is a versatile aircraft,
designed to be flown for sport or Pylon racing.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:09 AM Page 55
E-flite installed a slot in the fuselage for the
speed control. Its position allows the cooling
air to be directed over the speed control.
Although it’s considered a “smaller”
model, there is plenty of room inside
for your radio equipment and battery.
The motor box is quite long, but it is sturdy
and resists twisting from the torque of the
motor.
everything possible to make the building process as simple
and as quick as possible.
The first step I took was to epoxy on the horizontal and
vertical stabilizer. I measured to find the center of the
horizontal stabilizer and fuselage and used these marks as
my initial reference to set the stabilizer.
Once I had the marks lined up, I double-checked that it
was centered from side to side. I also measured from the tip
of the stabilizer to the tip of the tail to ensure that it was
installed square with the fuselage. When I was happy with
the fit, I marked and cut away the covering so that I would
have a good wood-to-wood joint.
Make sure the stabilizer is as far forward in the slot as
possible, because the elevators are attached to one another
with a prebent piece of piano wire that needs to fit down in
the cut-out part of the fuselage. After that had set up for a
little bit (I used 5-minute epoxy), I attached the vertical
stabilizer. This was simple because the stabilizer and filler
block are all one piece. All I had to do was line it up and
glue it down.
Don’t forget to cut the covering away on the horizontal
stabilizer to make sure you have a good joint. Don’t
forget to put the elevator connecting rod in before you
glue it down; I almost got caught on this.
Use a little tape to hold everything down and tight while
the epoxy cures. While waiting for the epoxy to cure, I
started working on the wings. This kit uses an aileron servo
in each wing, which is recessed into the wing under
preconstructed hatches; even the blocks to attach the servos
to are preinstalled. I did have to do a little trimming on these
tabs because they are designed around the JR 368 servo
which is a smaller servo than the JR Sport MN48 servos that
I used.
The airfoil is fairly thin so I shifted the servos toward the
LE to ensure that I would have room for the servo. After I
had the servos installed and centered, and the servo arms
installed, I fed the wire through the wing with the prerun
string and screwed the hatches down.
Depending on the length of the servo lead, you may need
to add an extension to get the wire all the way out of the
wing (I used a 6-inch extension in each wing).
As I stated earlier, CA-type hinges are used and all of the
slots are precut. I did have to cut the covering away for the
bottom hinge on the rudder. During this process, I had to
laugh. Thanks to the predrilled control horn holes, I
discovered that I had installed the horizontal stabilizer
56 MODEL AVIATION
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:10 AM Page 56
Elevators are held on with three CA hinges and connected
to each other with a prebent piece of piano wire.
+
• Level of completeness out of the box
• Can be raced or flown as a sport flyer
• Easy wing attachment
• Secure hatch provides quick battery
access -•
E-flite Power 25 provides a lot
of torque
Pluses and Min uses
Test Model Details
Power: E-flite Power 25 (1,250kV)
outrunner motor, 60 amp ESC
Battery: E-flite four-cell, 2,500 mAh
Li-Poly
Propeller: APC 10 x 7E or APC 8 x 8E
for racing
Radio system: JR X9303 transmitter,
Spektrum AR6210 DSM2 receiver,
four JR Sport MN-48 servos, two
6-inch servo extensions
Ready-to-fly weight: 3.25 pounds
Flight duration: 7-10 minutes,
4 minutes for racing
Specifications
Model type: RC Sport
Skill level: Beginner builder;
intermediate pilot
Wingspan: 48 inches
Wing area: 378 square inches
Length: 33 inches
Weight: 3.25 pounds
Wing loading: 19.81 ounces/square
foot
Power system: 600-850 watts
Radio: Four channels with four servos
Construction: Balsa and light plywood
Price: $149.99
upside down. Fortunately, this is a flat surface so it had no ill effect on
the airplane.
To complete the installation of the control surfaces, only two more
steps are necessary. You need to mount the control horns, which is made
easy by the predrilled holes. The next step is to hook up the pushrods,
again simplified because they are precut and installed for you.
The only things I added that weren’t included in the kit were small
pieces of fuel tubing to prevent the clevis from opening during flight. I
put the tail servos in the precut spot, centered them, and hooked up the
pushrods.
At this point, all of the control surfaces have been installed and
hooked up to the radio gear, so I moved on to the power plant and speed
control installation. This was incredibly simple because E-flite had the
forethought to install a slot in the fuselage for the speed control. The
only difficult part of this was getting the Velcro strap around it and
tight enough to keep it in place.
I then bolted on the motor, routed the wiring, and hooked it up to the
speed control.
Tip: for the E-flite Power 25 motor, you will want to use the short
stand-offs included in the kit. I also added a washer to give myself a
little more clearance between the cowling and spinner. Finally, I
installed the AR6210 receiver in front of the tail surface servos and the
satellite receiver toward the front of the airplane on the left side with
some Velcro.
The last step was the installation of the landing gear, wheels, and
wheel pants. The hardest part was cutting out the landing gear cuffs
from the vacuum-formed plastic; however, there are indentions molded
in to show you where to cut.
I installed the landing gear, slid the cuffs over them, and taped them
down with clear tape. This essentially completed the fuselage around
the landing gear. The wheels and wheel pants were again made easy
thanks to the forethought of E-flite.
E-flite provides a complete kit including
an extensive hardware package.
September 2011 57
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:11 AM Page 57
58 MODEL AVIATION
Flying: As I stated at the beginning of the article, the
Shoestring was designed to be a nice, easy sport flyer that can
be turned into a Pylon racer by simply adjusting the rates on
the control surfaces and putting on a different propeller. Eflite
has done an exceptional job of completing this objective.
Since I began Pylon racing approximately two years ago,
it is the only type of flying I do. Because of this I decided to
test that side of the model first.
As I mentioned earlier, EF1 is a new class of Pylon racing
that is being developed to entice additional pilots into the
racing world. It is designed to be an entry-level class that any
and all can enjoy. It’s flown on a 375-foot, three-pylon course
or a 400-foot, two-pylon course, which allows it to be flown
almost anywhere, including at some of the tightest fields.
Additionally, the model type, motor, and batteries are
going to be limited and must go through an approval process
to keep the playing field level. You can get more details of
the rules at RCGroups in a forum titled “Electric Formula
One: List of Recommended and Approved Components,”
and, of course, on the National Miniature Pylon Racing
Association (NMPRA) website.
The original design of the full-scale Shoestring was for air
racing, and this can be seen in the model’s speed and flight
characteristics. Although it was only flying slightly more than
100 mph, it felt much faster because of the shorter course. It
tracked straight and true through the corners with no need for
rudder input.
As it exited the turn and I let off of the elevator, it would
stop turning and track straight ahead toward the next turn,
waiting anxiously for me to tell it what to do next. I typically
like to keep my racer at roughly a 45° knife-edge as I’m
heading to the next pylon because it requires less aileron
input to get ready for the turn. However, I had to “flatten”
the Shoestring out slightly more because it felt like it was
slipping out of the sky toward the end of the straightaway.
Another characteristic of a good racer is minimal speed
loss in the turns, and the Shoestring appeared to possess this
quality. I was told to expect approximately 4 minutes of
flight time at full throttle so I set my timer at 3 minutes.
When it beeped I began my landing approach.
To my surprise, the airplane had no slow-flight bad
habits. It does take a longer approach, and because it’s
designed for racing, the airframe doesn’t create much drag.
As such, it takes some time to bleed off speed.
I had two batteries left so I took it up for two more flights
to make sure my initial assessment was accurate. I’m happy
to report that the Shoestring performed well flight after
flight.
The Shoestring flies so well it is relaxing to fly it. Opposite
aileron and down-elevator were needed to track straight in
knife-edge flight.
Photos by the author
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:12 AM Page 58
September 2011 59
Sport Flying: Since I had used up all the batteries I had on
the pylon flights, I had to come home and charge them and
test the airplane’s sport-flying ability on another day.
Unfortunately, the day I chose had wind speeds of
approximately 10-15 mph. To my surprise the Shoestring
took the wind and asked, “What else you got?”
It got bumped around, but it was easy to keep on track and
I felt comfortable having it a few feet off the deck, even
inverted. With the control rates turned up, it handled all of the
scale aerobatics with ease. Although I didn’t try it before to
writing the review, I have confidence that the control surfaces
are large enough to do some basic 3-D aerobatics.
Conclusion: If you have thought to yourself, “I’d like to get
into Pylon racing but I don’t want to buy an airplane just for
that,” then the Shoestring and the new EF1 class are for you.
Although the Shoestring was designed for racing, E-flite has
done a great job of making it a sport model that can be raced,
or if you prefer, a racing airplane that can be sport flown. MA
Manufacturer/Distributor:
E-flite/Horizon Hobby
4105 Fieldstone Rd.
Champaign, IL 61822
(800) 338-4639
www.e-fliterc.com
www.horizonhobby.com
Sources:
JR Radio
(877) 504-0233
www.jrradios.com
Spektrum RC
(800) 338-4639
www.spektrumrc.com
APC Propellers
(530) 661-0399
www.apcprop.com
RCGroups
www.rcgroups.com
NMPRA
www.NMPRA.org
On Saturday morning, July 9, the 2011
AMA Nationals Pylon Racing event wrapped
up with an Electric Formula One (EF1)
contest. The 43 airplanes entered in the event
were primarily E-flite LR-1A Pogos and
Shoestrings, along with a few other
prototypes and kit-built models to round out
the field.
Horizon Hobby/E-flite sponsored the
event and gave every entrant a nice pilot’s
package. Pete Bergstrom announced that Eflite
was going to release the Shoestring 15e
EF1 Racer in roughly mid-October.
I was able to get some practice time on
Thursday and Friday which allowed me to
fine-tune my throws and trim on the airplane.
The Shoestring was flying well because of the
flight characteristics of the airplane, and I was
feeling reasonably confident.
I managed to place first and third in my
first two rounds of competition. In my third
round, I was trying to get the jump on Travis
Flynn and ended up running into Pylon Two,
putting an early end to the Shoestring’s racing
career. This unfortunate occurrence happens
in racing.
The Shoestring 15e EF1 Racer was a very
competitive airplane that was easy to fly and
take off, even with downwind takeoffs. It
didn’t take nearly the amount of controls
some of the other pilots mentioned their
models needed. It simply took the commands
I gave it and asked, “What’s next?”
The Shoestring fits the intent of this class
perfectly. It is a great weekday sport flyer that
can be turned into a competitive race airplane
with some simple control surface-rate
changes and installing the APC 8 x 8E
propeller.
I plan to get a new one in October when
they come out. MA
—Lonnie Finch
Horizon Hobby/E-flite sponsored
the Electric Formula One (EF1) contest
The E-flite Shoestring ARF is
designed to be flown for sport or
Pylon racing. It looks anxious to
fly just sitting on the runway.
Although easy enough to operate
one-handed, the hatch is very secure.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:14 AM Page 59
Edition: Model Aviation - 2011/09
Page Numbers: 54,55,56,57,58,59
September 2011 55
GO FAST and turn left is a phrase you will hear every
once in a while, especially if you hang around Pylon racers.
Have you ever watched a Pylon race and thought, “That
looks like a lot of fun?” Well the new E-flite Shoestring
might be the airplane that lets you see how fun it can be.
In 2009, discussions began to start an electric-powered
scale racing class: Electric Formula One (EF1). It was
developed as an inexpensive, entry-level event that uses
readily available ARFs. The hope is that it will appeal to
pilots at a grass-roots level.
The airplanes are designed so that they can be flown for
sport during the week and raced on the weekend. The goal
is to bring in new racers ranging from new to experienced
pilots.
The aircraft are based on Scale Formula 1 racers with
375 square inches of wing area. The target speed is in the
110-120 mph range using components available at the local
hobby store. With a few power equipment changes, you
could easily push the speeds to 135-140 mph. These
changes are not allowed under the current EF1 rules, but I
could see, assuming the class takes off as hoped, a second
“professional” EF1 class being created to allow them.
Construction: In typical E-flite fashion, the Shoestring
ARF is a very complete kit. Short
of a little epoxy, CA, a few tools,
and some very minor
miscellaneous items, you’ll find
everything needed in the box.
When you first open the box
you see the care E-flite has taken
with this kit. Each part is
wrapped and packed in its own
spot in the box, sectioned off
with cardboard. Upon inspecting the parts that were
included, I discovered a very complete hardware kit which
included two different length engine standoffs, precut and
prebent aileron pushrods, all bolts (metric) and screws
needed, and control horns.
As is typical with most sport airplanes of this size, CAtype
hinges are used to attach the control surfaces. They
were all installed (but not glued) in precut slots. All of the
pushrods have been cut to length and have the Z-bends
completed.
The elevator and rudder pushrods have even been
installed into the fuselage. E-flite has predrilled all the
control horn holes into the control surfaces. The wheel
pants have been precut and drilled, too. They are also
formed with an indention for the landing gear to sit in,
making them very secure. The fiberglass cowling is wellconstructed
and follows the contours of the airframe nicely.
As of the date of my review, the instruction manual was
still being written, but if you have any ARF assembly
experience at all, it really isn’t necessary. E-flite has done g
The E-flite Shoestring ARF 15e EF1 is a versatile aircraft,
designed to be flown for sport or Pylon racing.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:09 AM Page 55
E-flite installed a slot in the fuselage for the
speed control. Its position allows the cooling
air to be directed over the speed control.
Although it’s considered a “smaller”
model, there is plenty of room inside
for your radio equipment and battery.
The motor box is quite long, but it is sturdy
and resists twisting from the torque of the
motor.
everything possible to make the building process as simple
and as quick as possible.
The first step I took was to epoxy on the horizontal and
vertical stabilizer. I measured to find the center of the
horizontal stabilizer and fuselage and used these marks as
my initial reference to set the stabilizer.
Once I had the marks lined up, I double-checked that it
was centered from side to side. I also measured from the tip
of the stabilizer to the tip of the tail to ensure that it was
installed square with the fuselage. When I was happy with
the fit, I marked and cut away the covering so that I would
have a good wood-to-wood joint.
Make sure the stabilizer is as far forward in the slot as
possible, because the elevators are attached to one another
with a prebent piece of piano wire that needs to fit down in
the cut-out part of the fuselage. After that had set up for a
little bit (I used 5-minute epoxy), I attached the vertical
stabilizer. This was simple because the stabilizer and filler
block are all one piece. All I had to do was line it up and
glue it down.
Don’t forget to cut the covering away on the horizontal
stabilizer to make sure you have a good joint. Don’t
forget to put the elevator connecting rod in before you
glue it down; I almost got caught on this.
Use a little tape to hold everything down and tight while
the epoxy cures. While waiting for the epoxy to cure, I
started working on the wings. This kit uses an aileron servo
in each wing, which is recessed into the wing under
preconstructed hatches; even the blocks to attach the servos
to are preinstalled. I did have to do a little trimming on these
tabs because they are designed around the JR 368 servo
which is a smaller servo than the JR Sport MN48 servos that
I used.
The airfoil is fairly thin so I shifted the servos toward the
LE to ensure that I would have room for the servo. After I
had the servos installed and centered, and the servo arms
installed, I fed the wire through the wing with the prerun
string and screwed the hatches down.
Depending on the length of the servo lead, you may need
to add an extension to get the wire all the way out of the
wing (I used a 6-inch extension in each wing).
As I stated earlier, CA-type hinges are used and all of the
slots are precut. I did have to cut the covering away for the
bottom hinge on the rudder. During this process, I had to
laugh. Thanks to the predrilled control horn holes, I
discovered that I had installed the horizontal stabilizer
56 MODEL AVIATION
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:10 AM Page 56
Elevators are held on with three CA hinges and connected
to each other with a prebent piece of piano wire.
+
• Level of completeness out of the box
• Can be raced or flown as a sport flyer
• Easy wing attachment
• Secure hatch provides quick battery
access -•
E-flite Power 25 provides a lot
of torque
Pluses and Min uses
Test Model Details
Power: E-flite Power 25 (1,250kV)
outrunner motor, 60 amp ESC
Battery: E-flite four-cell, 2,500 mAh
Li-Poly
Propeller: APC 10 x 7E or APC 8 x 8E
for racing
Radio system: JR X9303 transmitter,
Spektrum AR6210 DSM2 receiver,
four JR Sport MN-48 servos, two
6-inch servo extensions
Ready-to-fly weight: 3.25 pounds
Flight duration: 7-10 minutes,
4 minutes for racing
Specifications
Model type: RC Sport
Skill level: Beginner builder;
intermediate pilot
Wingspan: 48 inches
Wing area: 378 square inches
Length: 33 inches
Weight: 3.25 pounds
Wing loading: 19.81 ounces/square
foot
Power system: 600-850 watts
Radio: Four channels with four servos
Construction: Balsa and light plywood
Price: $149.99
upside down. Fortunately, this is a flat surface so it had no ill effect on
the airplane.
To complete the installation of the control surfaces, only two more
steps are necessary. You need to mount the control horns, which is made
easy by the predrilled holes. The next step is to hook up the pushrods,
again simplified because they are precut and installed for you.
The only things I added that weren’t included in the kit were small
pieces of fuel tubing to prevent the clevis from opening during flight. I
put the tail servos in the precut spot, centered them, and hooked up the
pushrods.
At this point, all of the control surfaces have been installed and
hooked up to the radio gear, so I moved on to the power plant and speed
control installation. This was incredibly simple because E-flite had the
forethought to install a slot in the fuselage for the speed control. The
only difficult part of this was getting the Velcro strap around it and
tight enough to keep it in place.
I then bolted on the motor, routed the wiring, and hooked it up to the
speed control.
Tip: for the E-flite Power 25 motor, you will want to use the short
stand-offs included in the kit. I also added a washer to give myself a
little more clearance between the cowling and spinner. Finally, I
installed the AR6210 receiver in front of the tail surface servos and the
satellite receiver toward the front of the airplane on the left side with
some Velcro.
The last step was the installation of the landing gear, wheels, and
wheel pants. The hardest part was cutting out the landing gear cuffs
from the vacuum-formed plastic; however, there are indentions molded
in to show you where to cut.
I installed the landing gear, slid the cuffs over them, and taped them
down with clear tape. This essentially completed the fuselage around
the landing gear. The wheels and wheel pants were again made easy
thanks to the forethought of E-flite.
E-flite provides a complete kit including
an extensive hardware package.
September 2011 57
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:11 AM Page 57
58 MODEL AVIATION
Flying: As I stated at the beginning of the article, the
Shoestring was designed to be a nice, easy sport flyer that can
be turned into a Pylon racer by simply adjusting the rates on
the control surfaces and putting on a different propeller. Eflite
has done an exceptional job of completing this objective.
Since I began Pylon racing approximately two years ago,
it is the only type of flying I do. Because of this I decided to
test that side of the model first.
As I mentioned earlier, EF1 is a new class of Pylon racing
that is being developed to entice additional pilots into the
racing world. It is designed to be an entry-level class that any
and all can enjoy. It’s flown on a 375-foot, three-pylon course
or a 400-foot, two-pylon course, which allows it to be flown
almost anywhere, including at some of the tightest fields.
Additionally, the model type, motor, and batteries are
going to be limited and must go through an approval process
to keep the playing field level. You can get more details of
the rules at RCGroups in a forum titled “Electric Formula
One: List of Recommended and Approved Components,”
and, of course, on the National Miniature Pylon Racing
Association (NMPRA) website.
The original design of the full-scale Shoestring was for air
racing, and this can be seen in the model’s speed and flight
characteristics. Although it was only flying slightly more than
100 mph, it felt much faster because of the shorter course. It
tracked straight and true through the corners with no need for
rudder input.
As it exited the turn and I let off of the elevator, it would
stop turning and track straight ahead toward the next turn,
waiting anxiously for me to tell it what to do next. I typically
like to keep my racer at roughly a 45° knife-edge as I’m
heading to the next pylon because it requires less aileron
input to get ready for the turn. However, I had to “flatten”
the Shoestring out slightly more because it felt like it was
slipping out of the sky toward the end of the straightaway.
Another characteristic of a good racer is minimal speed
loss in the turns, and the Shoestring appeared to possess this
quality. I was told to expect approximately 4 minutes of
flight time at full throttle so I set my timer at 3 minutes.
When it beeped I began my landing approach.
To my surprise, the airplane had no slow-flight bad
habits. It does take a longer approach, and because it’s
designed for racing, the airframe doesn’t create much drag.
As such, it takes some time to bleed off speed.
I had two batteries left so I took it up for two more flights
to make sure my initial assessment was accurate. I’m happy
to report that the Shoestring performed well flight after
flight.
The Shoestring flies so well it is relaxing to fly it. Opposite
aileron and down-elevator were needed to track straight in
knife-edge flight.
Photos by the author
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:12 AM Page 58
September 2011 59
Sport Flying: Since I had used up all the batteries I had on
the pylon flights, I had to come home and charge them and
test the airplane’s sport-flying ability on another day.
Unfortunately, the day I chose had wind speeds of
approximately 10-15 mph. To my surprise the Shoestring
took the wind and asked, “What else you got?”
It got bumped around, but it was easy to keep on track and
I felt comfortable having it a few feet off the deck, even
inverted. With the control rates turned up, it handled all of the
scale aerobatics with ease. Although I didn’t try it before to
writing the review, I have confidence that the control surfaces
are large enough to do some basic 3-D aerobatics.
Conclusion: If you have thought to yourself, “I’d like to get
into Pylon racing but I don’t want to buy an airplane just for
that,” then the Shoestring and the new EF1 class are for you.
Although the Shoestring was designed for racing, E-flite has
done a great job of making it a sport model that can be raced,
or if you prefer, a racing airplane that can be sport flown. MA
Manufacturer/Distributor:
E-flite/Horizon Hobby
4105 Fieldstone Rd.
Champaign, IL 61822
(800) 338-4639
www.e-fliterc.com
www.horizonhobby.com
Sources:
JR Radio
(877) 504-0233
www.jrradios.com
Spektrum RC
(800) 338-4639
www.spektrumrc.com
APC Propellers
(530) 661-0399
www.apcprop.com
RCGroups
www.rcgroups.com
NMPRA
www.NMPRA.org
On Saturday morning, July 9, the 2011
AMA Nationals Pylon Racing event wrapped
up with an Electric Formula One (EF1)
contest. The 43 airplanes entered in the event
were primarily E-flite LR-1A Pogos and
Shoestrings, along with a few other
prototypes and kit-built models to round out
the field.
Horizon Hobby/E-flite sponsored the
event and gave every entrant a nice pilot’s
package. Pete Bergstrom announced that Eflite
was going to release the Shoestring 15e
EF1 Racer in roughly mid-October.
I was able to get some practice time on
Thursday and Friday which allowed me to
fine-tune my throws and trim on the airplane.
The Shoestring was flying well because of the
flight characteristics of the airplane, and I was
feeling reasonably confident.
I managed to place first and third in my
first two rounds of competition. In my third
round, I was trying to get the jump on Travis
Flynn and ended up running into Pylon Two,
putting an early end to the Shoestring’s racing
career. This unfortunate occurrence happens
in racing.
The Shoestring 15e EF1 Racer was a very
competitive airplane that was easy to fly and
take off, even with downwind takeoffs. It
didn’t take nearly the amount of controls
some of the other pilots mentioned their
models needed. It simply took the commands
I gave it and asked, “What’s next?”
The Shoestring fits the intent of this class
perfectly. It is a great weekday sport flyer that
can be turned into a competitive race airplane
with some simple control surface-rate
changes and installing the APC 8 x 8E
propeller.
I plan to get a new one in October when
they come out. MA
—Lonnie Finch
Horizon Hobby/E-flite sponsored
the Electric Formula One (EF1) contest
The E-flite Shoestring ARF is
designed to be flown for sport or
Pylon racing. It looks anxious to
fly just sitting on the runway.
Although easy enough to operate
one-handed, the hatch is very secure.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:14 AM Page 59
Edition: Model Aviation - 2011/09
Page Numbers: 54,55,56,57,58,59
September 2011 55
GO FAST and turn left is a phrase you will hear every
once in a while, especially if you hang around Pylon racers.
Have you ever watched a Pylon race and thought, “That
looks like a lot of fun?” Well the new E-flite Shoestring
might be the airplane that lets you see how fun it can be.
In 2009, discussions began to start an electric-powered
scale racing class: Electric Formula One (EF1). It was
developed as an inexpensive, entry-level event that uses
readily available ARFs. The hope is that it will appeal to
pilots at a grass-roots level.
The airplanes are designed so that they can be flown for
sport during the week and raced on the weekend. The goal
is to bring in new racers ranging from new to experienced
pilots.
The aircraft are based on Scale Formula 1 racers with
375 square inches of wing area. The target speed is in the
110-120 mph range using components available at the local
hobby store. With a few power equipment changes, you
could easily push the speeds to 135-140 mph. These
changes are not allowed under the current EF1 rules, but I
could see, assuming the class takes off as hoped, a second
“professional” EF1 class being created to allow them.
Construction: In typical E-flite fashion, the Shoestring
ARF is a very complete kit. Short
of a little epoxy, CA, a few tools,
and some very minor
miscellaneous items, you’ll find
everything needed in the box.
When you first open the box
you see the care E-flite has taken
with this kit. Each part is
wrapped and packed in its own
spot in the box, sectioned off
with cardboard. Upon inspecting the parts that were
included, I discovered a very complete hardware kit which
included two different length engine standoffs, precut and
prebent aileron pushrods, all bolts (metric) and screws
needed, and control horns.
As is typical with most sport airplanes of this size, CAtype
hinges are used to attach the control surfaces. They
were all installed (but not glued) in precut slots. All of the
pushrods have been cut to length and have the Z-bends
completed.
The elevator and rudder pushrods have even been
installed into the fuselage. E-flite has predrilled all the
control horn holes into the control surfaces. The wheel
pants have been precut and drilled, too. They are also
formed with an indention for the landing gear to sit in,
making them very secure. The fiberglass cowling is wellconstructed
and follows the contours of the airframe nicely.
As of the date of my review, the instruction manual was
still being written, but if you have any ARF assembly
experience at all, it really isn’t necessary. E-flite has done g
The E-flite Shoestring ARF 15e EF1 is a versatile aircraft,
designed to be flown for sport or Pylon racing.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:09 AM Page 55
E-flite installed a slot in the fuselage for the
speed control. Its position allows the cooling
air to be directed over the speed control.
Although it’s considered a “smaller”
model, there is plenty of room inside
for your radio equipment and battery.
The motor box is quite long, but it is sturdy
and resists twisting from the torque of the
motor.
everything possible to make the building process as simple
and as quick as possible.
The first step I took was to epoxy on the horizontal and
vertical stabilizer. I measured to find the center of the
horizontal stabilizer and fuselage and used these marks as
my initial reference to set the stabilizer.
Once I had the marks lined up, I double-checked that it
was centered from side to side. I also measured from the tip
of the stabilizer to the tip of the tail to ensure that it was
installed square with the fuselage. When I was happy with
the fit, I marked and cut away the covering so that I would
have a good wood-to-wood joint.
Make sure the stabilizer is as far forward in the slot as
possible, because the elevators are attached to one another
with a prebent piece of piano wire that needs to fit down in
the cut-out part of the fuselage. After that had set up for a
little bit (I used 5-minute epoxy), I attached the vertical
stabilizer. This was simple because the stabilizer and filler
block are all one piece. All I had to do was line it up and
glue it down.
Don’t forget to cut the covering away on the horizontal
stabilizer to make sure you have a good joint. Don’t
forget to put the elevator connecting rod in before you
glue it down; I almost got caught on this.
Use a little tape to hold everything down and tight while
the epoxy cures. While waiting for the epoxy to cure, I
started working on the wings. This kit uses an aileron servo
in each wing, which is recessed into the wing under
preconstructed hatches; even the blocks to attach the servos
to are preinstalled. I did have to do a little trimming on these
tabs because they are designed around the JR 368 servo
which is a smaller servo than the JR Sport MN48 servos that
I used.
The airfoil is fairly thin so I shifted the servos toward the
LE to ensure that I would have room for the servo. After I
had the servos installed and centered, and the servo arms
installed, I fed the wire through the wing with the prerun
string and screwed the hatches down.
Depending on the length of the servo lead, you may need
to add an extension to get the wire all the way out of the
wing (I used a 6-inch extension in each wing).
As I stated earlier, CA-type hinges are used and all of the
slots are precut. I did have to cut the covering away for the
bottom hinge on the rudder. During this process, I had to
laugh. Thanks to the predrilled control horn holes, I
discovered that I had installed the horizontal stabilizer
56 MODEL AVIATION
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:10 AM Page 56
Elevators are held on with three CA hinges and connected
to each other with a prebent piece of piano wire.
+
• Level of completeness out of the box
• Can be raced or flown as a sport flyer
• Easy wing attachment
• Secure hatch provides quick battery
access -•
E-flite Power 25 provides a lot
of torque
Pluses and Min uses
Test Model Details
Power: E-flite Power 25 (1,250kV)
outrunner motor, 60 amp ESC
Battery: E-flite four-cell, 2,500 mAh
Li-Poly
Propeller: APC 10 x 7E or APC 8 x 8E
for racing
Radio system: JR X9303 transmitter,
Spektrum AR6210 DSM2 receiver,
four JR Sport MN-48 servos, two
6-inch servo extensions
Ready-to-fly weight: 3.25 pounds
Flight duration: 7-10 minutes,
4 minutes for racing
Specifications
Model type: RC Sport
Skill level: Beginner builder;
intermediate pilot
Wingspan: 48 inches
Wing area: 378 square inches
Length: 33 inches
Weight: 3.25 pounds
Wing loading: 19.81 ounces/square
foot
Power system: 600-850 watts
Radio: Four channels with four servos
Construction: Balsa and light plywood
Price: $149.99
upside down. Fortunately, this is a flat surface so it had no ill effect on
the airplane.
To complete the installation of the control surfaces, only two more
steps are necessary. You need to mount the control horns, which is made
easy by the predrilled holes. The next step is to hook up the pushrods,
again simplified because they are precut and installed for you.
The only things I added that weren’t included in the kit were small
pieces of fuel tubing to prevent the clevis from opening during flight. I
put the tail servos in the precut spot, centered them, and hooked up the
pushrods.
At this point, all of the control surfaces have been installed and
hooked up to the radio gear, so I moved on to the power plant and speed
control installation. This was incredibly simple because E-flite had the
forethought to install a slot in the fuselage for the speed control. The
only difficult part of this was getting the Velcro strap around it and
tight enough to keep it in place.
I then bolted on the motor, routed the wiring, and hooked it up to the
speed control.
Tip: for the E-flite Power 25 motor, you will want to use the short
stand-offs included in the kit. I also added a washer to give myself a
little more clearance between the cowling and spinner. Finally, I
installed the AR6210 receiver in front of the tail surface servos and the
satellite receiver toward the front of the airplane on the left side with
some Velcro.
The last step was the installation of the landing gear, wheels, and
wheel pants. The hardest part was cutting out the landing gear cuffs
from the vacuum-formed plastic; however, there are indentions molded
in to show you where to cut.
I installed the landing gear, slid the cuffs over them, and taped them
down with clear tape. This essentially completed the fuselage around
the landing gear. The wheels and wheel pants were again made easy
thanks to the forethought of E-flite.
E-flite provides a complete kit including
an extensive hardware package.
September 2011 57
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:11 AM Page 57
58 MODEL AVIATION
Flying: As I stated at the beginning of the article, the
Shoestring was designed to be a nice, easy sport flyer that can
be turned into a Pylon racer by simply adjusting the rates on
the control surfaces and putting on a different propeller. Eflite
has done an exceptional job of completing this objective.
Since I began Pylon racing approximately two years ago,
it is the only type of flying I do. Because of this I decided to
test that side of the model first.
As I mentioned earlier, EF1 is a new class of Pylon racing
that is being developed to entice additional pilots into the
racing world. It is designed to be an entry-level class that any
and all can enjoy. It’s flown on a 375-foot, three-pylon course
or a 400-foot, two-pylon course, which allows it to be flown
almost anywhere, including at some of the tightest fields.
Additionally, the model type, motor, and batteries are
going to be limited and must go through an approval process
to keep the playing field level. You can get more details of
the rules at RCGroups in a forum titled “Electric Formula
One: List of Recommended and Approved Components,”
and, of course, on the National Miniature Pylon Racing
Association (NMPRA) website.
The original design of the full-scale Shoestring was for air
racing, and this can be seen in the model’s speed and flight
characteristics. Although it was only flying slightly more than
100 mph, it felt much faster because of the shorter course. It
tracked straight and true through the corners with no need for
rudder input.
As it exited the turn and I let off of the elevator, it would
stop turning and track straight ahead toward the next turn,
waiting anxiously for me to tell it what to do next. I typically
like to keep my racer at roughly a 45° knife-edge as I’m
heading to the next pylon because it requires less aileron
input to get ready for the turn. However, I had to “flatten”
the Shoestring out slightly more because it felt like it was
slipping out of the sky toward the end of the straightaway.
Another characteristic of a good racer is minimal speed
loss in the turns, and the Shoestring appeared to possess this
quality. I was told to expect approximately 4 minutes of
flight time at full throttle so I set my timer at 3 minutes.
When it beeped I began my landing approach.
To my surprise, the airplane had no slow-flight bad
habits. It does take a longer approach, and because it’s
designed for racing, the airframe doesn’t create much drag.
As such, it takes some time to bleed off speed.
I had two batteries left so I took it up for two more flights
to make sure my initial assessment was accurate. I’m happy
to report that the Shoestring performed well flight after
flight.
The Shoestring flies so well it is relaxing to fly it. Opposite
aileron and down-elevator were needed to track straight in
knife-edge flight.
Photos by the author
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:12 AM Page 58
September 2011 59
Sport Flying: Since I had used up all the batteries I had on
the pylon flights, I had to come home and charge them and
test the airplane’s sport-flying ability on another day.
Unfortunately, the day I chose had wind speeds of
approximately 10-15 mph. To my surprise the Shoestring
took the wind and asked, “What else you got?”
It got bumped around, but it was easy to keep on track and
I felt comfortable having it a few feet off the deck, even
inverted. With the control rates turned up, it handled all of the
scale aerobatics with ease. Although I didn’t try it before to
writing the review, I have confidence that the control surfaces
are large enough to do some basic 3-D aerobatics.
Conclusion: If you have thought to yourself, “I’d like to get
into Pylon racing but I don’t want to buy an airplane just for
that,” then the Shoestring and the new EF1 class are for you.
Although the Shoestring was designed for racing, E-flite has
done a great job of making it a sport model that can be raced,
or if you prefer, a racing airplane that can be sport flown. MA
Manufacturer/Distributor:
E-flite/Horizon Hobby
4105 Fieldstone Rd.
Champaign, IL 61822
(800) 338-4639
www.e-fliterc.com
www.horizonhobby.com
Sources:
JR Radio
(877) 504-0233
www.jrradios.com
Spektrum RC
(800) 338-4639
www.spektrumrc.com
APC Propellers
(530) 661-0399
www.apcprop.com
RCGroups
www.rcgroups.com
NMPRA
www.NMPRA.org
On Saturday morning, July 9, the 2011
AMA Nationals Pylon Racing event wrapped
up with an Electric Formula One (EF1)
contest. The 43 airplanes entered in the event
were primarily E-flite LR-1A Pogos and
Shoestrings, along with a few other
prototypes and kit-built models to round out
the field.
Horizon Hobby/E-flite sponsored the
event and gave every entrant a nice pilot’s
package. Pete Bergstrom announced that Eflite
was going to release the Shoestring 15e
EF1 Racer in roughly mid-October.
I was able to get some practice time on
Thursday and Friday which allowed me to
fine-tune my throws and trim on the airplane.
The Shoestring was flying well because of the
flight characteristics of the airplane, and I was
feeling reasonably confident.
I managed to place first and third in my
first two rounds of competition. In my third
round, I was trying to get the jump on Travis
Flynn and ended up running into Pylon Two,
putting an early end to the Shoestring’s racing
career. This unfortunate occurrence happens
in racing.
The Shoestring 15e EF1 Racer was a very
competitive airplane that was easy to fly and
take off, even with downwind takeoffs. It
didn’t take nearly the amount of controls
some of the other pilots mentioned their
models needed. It simply took the commands
I gave it and asked, “What’s next?”
The Shoestring fits the intent of this class
perfectly. It is a great weekday sport flyer that
can be turned into a competitive race airplane
with some simple control surface-rate
changes and installing the APC 8 x 8E
propeller.
I plan to get a new one in October when
they come out. MA
—Lonnie Finch
Horizon Hobby/E-flite sponsored
the Electric Formula One (EF1) contest
The E-flite Shoestring ARF is
designed to be flown for sport or
Pylon racing. It looks anxious to
fly just sitting on the runway.
Although easy enough to operate
one-handed, the hatch is very secure.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:14 AM Page 59
Edition: Model Aviation - 2011/09
Page Numbers: 54,55,56,57,58,59
September 2011 55
GO FAST and turn left is a phrase you will hear every
once in a while, especially if you hang around Pylon racers.
Have you ever watched a Pylon race and thought, “That
looks like a lot of fun?” Well the new E-flite Shoestring
might be the airplane that lets you see how fun it can be.
In 2009, discussions began to start an electric-powered
scale racing class: Electric Formula One (EF1). It was
developed as an inexpensive, entry-level event that uses
readily available ARFs. The hope is that it will appeal to
pilots at a grass-roots level.
The airplanes are designed so that they can be flown for
sport during the week and raced on the weekend. The goal
is to bring in new racers ranging from new to experienced
pilots.
The aircraft are based on Scale Formula 1 racers with
375 square inches of wing area. The target speed is in the
110-120 mph range using components available at the local
hobby store. With a few power equipment changes, you
could easily push the speeds to 135-140 mph. These
changes are not allowed under the current EF1 rules, but I
could see, assuming the class takes off as hoped, a second
“professional” EF1 class being created to allow them.
Construction: In typical E-flite fashion, the Shoestring
ARF is a very complete kit. Short
of a little epoxy, CA, a few tools,
and some very minor
miscellaneous items, you’ll find
everything needed in the box.
When you first open the box
you see the care E-flite has taken
with this kit. Each part is
wrapped and packed in its own
spot in the box, sectioned off
with cardboard. Upon inspecting the parts that were
included, I discovered a very complete hardware kit which
included two different length engine standoffs, precut and
prebent aileron pushrods, all bolts (metric) and screws
needed, and control horns.
As is typical with most sport airplanes of this size, CAtype
hinges are used to attach the control surfaces. They
were all installed (but not glued) in precut slots. All of the
pushrods have been cut to length and have the Z-bends
completed.
The elevator and rudder pushrods have even been
installed into the fuselage. E-flite has predrilled all the
control horn holes into the control surfaces. The wheel
pants have been precut and drilled, too. They are also
formed with an indention for the landing gear to sit in,
making them very secure. The fiberglass cowling is wellconstructed
and follows the contours of the airframe nicely.
As of the date of my review, the instruction manual was
still being written, but if you have any ARF assembly
experience at all, it really isn’t necessary. E-flite has done g
The E-flite Shoestring ARF 15e EF1 is a versatile aircraft,
designed to be flown for sport or Pylon racing.
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:09 AM Page 55
E-flite installed a slot in the fuselage for the
speed control. Its position allows the cooling
air to be directed over the speed control.
Although it’s considered a “smaller”
model, there is plenty of room inside
for your radio equipment and battery.
The motor box is quite long, but it is sturdy
and resists twisting from the torque of the
motor.
everything possible to make the building process as simple
and as quick as possible.
The first step I took was to epoxy on the horizontal and
vertical stabilizer. I measured to find the center of the
horizontal stabilizer and fuselage and used these marks as
my initial reference to set the stabilizer.
Once I had the marks lined up, I double-checked that it
was centered from side to side. I also measured from the tip
of the stabilizer to the tip of the tail to ensure that it was
installed square with the fuselage. When I was happy with
the fit, I marked and cut away the covering so that I would
have a good wood-to-wood joint.
Make sure the stabilizer is as far forward in the slot as
possible, because the elevators are attached to one another
with a prebent piece of piano wire that needs to fit down in
the cut-out part of the fuselage. After that had set up for a
little bit (I used 5-minute epoxy), I attached the vertical
stabilizer. This was simple because the stabilizer and filler
block are all one piece. All I had to do was line it up and
glue it down.
Don’t forget to cut the covering away on the horizontal
stabilizer to make sure you have a good joint. Don’t
forget to put the elevator connecting rod in before you
glue it down; I almost got caught on this.
Use a little tape to hold everything down and tight while
the epoxy cures. While waiting for the epoxy to cure, I
started working on the wings. This kit uses an aileron servo
in each wing, which is recessed into the wing under
preconstructed hatches; even the blocks to attach the servos
to are preinstalled. I did have to do a little trimming on these
tabs because they are designed around the JR 368 servo
which is a smaller servo than the JR Sport MN48 servos that
I used.
The airfoil is fairly thin so I shifted the servos toward the
LE to ensure that I would have room for the servo. After I
had the servos installed and centered, and the servo arms
installed, I fed the wire through the wing with the prerun
string and screwed the hatches down.
Depending on the length of the servo lead, you may need
to add an extension to get the wire all the way out of the
wing (I used a 6-inch extension in each wing).
As I stated earlier, CA-type hinges are used and all of the
slots are precut. I did have to cut the covering away for the
bottom hinge on the rudder. During this process, I had to
laugh. Thanks to the predrilled control horn holes, I
discovered that I had installed the horizontal stabilizer
56 MODEL AVIATION
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:10 AM Page 56
Elevators are held on with three CA hinges and connected
to each other with a prebent piece of piano wire.
+
• Level of completeness out of the box
• Can be raced or flown as a sport flyer
• Easy wing attachment
• Secure hatch provides quick battery
access -•
E-flite Power 25 provides a lot
of torque
Pluses and Min uses
Test Model Details
Power: E-flite Power 25 (1,250kV)
outrunner motor, 60 amp ESC
Battery: E-flite four-cell, 2,500 mAh
Li-Poly
Propeller: APC 10 x 7E or APC 8 x 8E
for racing
Radio system: JR X9303 transmitter,
Spektrum AR6210 DSM2 receiver,
four JR Sport MN-48 servos, two
6-inch servo extensions
Ready-to-fly weight: 3.25 pounds
Flight duration: 7-10 minutes,
4 minutes for racing
Specifications
Model type: RC Sport
Skill level: Beginner builder;
intermediate pilot
Wingspan: 48 inches
Wing area: 378 square inches
Length: 33 inches
Weight: 3.25 pounds
Wing loading: 19.81 ounces/square
foot
Power system: 600-850 watts
Radio: Four channels with four servos
Construction: Balsa and light plywood
Price: $149.99
upside down. Fortunately, this is a flat surface so it had no ill effect on
the airplane.
To complete the installation of the control surfaces, only two more
steps are necessary. You need to mount the control horns, which is made
easy by the predrilled holes. The next step is to hook up the pushrods,
again simplified because they are precut and installed for you.
The only things I added that weren’t included in the kit were small
pieces of fuel tubing to prevent the clevis from opening during flight. I
put the tail servos in the precut spot, centered them, and hooked up the
pushrods.
At this point, all of the control surfaces have been installed and
hooked up to the radio gear, so I moved on to the power plant and speed
control installation. This was incredibly simple because E-flite had the
forethought to install a slot in the fuselage for the speed control. The
only difficult part of this was getting the Velcro strap around it and
tight enough to keep it in place.
I then bolted on the motor, routed the wiring, and hooked it up to the
speed control.
Tip: for the E-flite Power 25 motor, you will want to use the short
stand-offs included in the kit. I also added a washer to give myself a
little more clearance between the cowling and spinner. Finally, I
installed the AR6210 receiver in front of the tail surface servos and the
satellite receiver toward the front of the airplane on the left side with
some Velcro.
The last step was the installation of the landing gear, wheels, and
wheel pants. The hardest part was cutting out the landing gear cuffs
from the vacuum-formed plastic; however, there are indentions molded
in to show you where to cut.
I installed the landing gear, slid the cuffs over them, and taped them
down with clear tape. This essentially completed the fuselage around
the landing gear. The wheels and wheel pants were again made easy
thanks to the forethought of E-flite.
E-flite provides a complete kit including
an extensive hardware package.
September 2011 57
09sig2.QXD_00MSTRPG.QXD 7/22/11 10:11 AM Page 57
58 MODEL AVIATION
Flying: As I stated at the beginning of the article, the
Shoestring was designed to be a nice, easy sport flyer that can
be turned into a Pylon racer by simply adjusting the rates on
the control surfaces and putting on a different propeller. Eflite
has done an exceptional job of completing this objective.
Since I began Pylon racing approximately two years ago,
it is the only type of flying I do. Because of this I decided to
test that side of the model first.
As I mentioned earlier, EF1 is a new class of Pylon racing
that is being developed to entice additional pilots into the
racing world. It is designed to be an entry-level class that any
and all can enjoy. It’s flown on a 375-foot, three-pylon course
or a 400-foot, two-pylon course, which allows it to be flown
almost anywhere, including at some of the tightest fields.
Additionally, the model type, motor, and batteries are
going to be limited and must go through an approval process
to keep the playing field level. You can get more details of
the rules at RCGroups in a forum titled “Electric Formula
One: List of Recommended and Approved Components,”
and, of course, on the National Miniature Pylon Racing
Association (NMPRA) website.
The original design of the full-scale Shoestring was for air
racing, and this can be seen in the model’s speed and flight
characteristics. Although it was only flying slightly more than
100 mph, it felt much faster because of the shorter course. It
tracked straight and true through the corners with no need for
rudder input.
As it exited the turn and I let off of the elevator, it would
stop turning and track straight ahead toward the next turn,
waiting anxiously for me to tell it what to do next. I typically
like to keep my racer at roughly a 45° knife-edge as I’m
heading to the next pylon because it requires less aileron
input to get ready for the turn. However, I had to “flatten”
the Shoestring out slightly more because it felt like it was
slipping out of the sky toward the end of the straightaway.
Another characteristic of a good racer is minimal speed
loss in the turns, and the Shoestring appeared to possess this
quality. I was told to expect approximately 4 minutes of
flight time at full throttle so I set my timer at 3 minutes.
When it beeped I began my landing approach.
To my surprise, the airplane had no slow-flight bad
habits. It does take a longer approach, and because it’s
designed for racing, the airframe doesn’t create much drag.
As such, it takes some time to bleed off speed.
I had two batteries left so I took it up for two more flights
to make sure my initial assessment was accurate. I’m happy
to report that the Shoestring performed well flight after
flight.
The Shoestring flies so well it is relaxing to fly it. Opposite
aileron and down-elevator were needed to track straight in
knife-edge flight.
Photos by the author
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Sport Flying: Since I had used up all the batteries I had on
the pylon flights, I had to come home and charge them and
test the airplane’s sport-flying ability on another day.
Unfortunately, the day I chose had wind speeds of
approximately 10-15 mph. To my surprise the Shoestring
took the wind and asked, “What else you got?”
It got bumped around, but it was easy to keep on track and
I felt comfortable having it a few feet off the deck, even
inverted. With the control rates turned up, it handled all of the
scale aerobatics with ease. Although I didn’t try it before to
writing the review, I have confidence that the control surfaces
are large enough to do some basic 3-D aerobatics.
Conclusion: If you have thought to yourself, “I’d like to get
into Pylon racing but I don’t want to buy an airplane just for
that,” then the Shoestring and the new EF1 class are for you.
Although the Shoestring was designed for racing, E-flite has
done a great job of making it a sport model that can be raced,
or if you prefer, a racing airplane that can be sport flown. MA
Manufacturer/Distributor:
E-flite/Horizon Hobby
4105 Fieldstone Rd.
Champaign, IL 61822
(800) 338-4639
www.e-fliterc.com
www.horizonhobby.com
Sources:
JR Radio
(877) 504-0233
www.jrradios.com
Spektrum RC
(800) 338-4639
www.spektrumrc.com
APC Propellers
(530) 661-0399
www.apcprop.com
RCGroups
www.rcgroups.com
NMPRA
www.NMPRA.org
On Saturday morning, July 9, the 2011
AMA Nationals Pylon Racing event wrapped
up with an Electric Formula One (EF1)
contest. The 43 airplanes entered in the event
were primarily E-flite LR-1A Pogos and
Shoestrings, along with a few other
prototypes and kit-built models to round out
the field.
Horizon Hobby/E-flite sponsored the
event and gave every entrant a nice pilot’s
package. Pete Bergstrom announced that Eflite
was going to release the Shoestring 15e
EF1 Racer in roughly mid-October.
I was able to get some practice time on
Thursday and Friday which allowed me to
fine-tune my throws and trim on the airplane.
The Shoestring was flying well because of the
flight characteristics of the airplane, and I was
feeling reasonably confident.
I managed to place first and third in my
first two rounds of competition. In my third
round, I was trying to get the jump on Travis
Flynn and ended up running into Pylon Two,
putting an early end to the Shoestring’s racing
career. This unfortunate occurrence happens
in racing.
The Shoestring 15e EF1 Racer was a very
competitive airplane that was easy to fly and
take off, even with downwind takeoffs. It
didn’t take nearly the amount of controls
some of the other pilots mentioned their
models needed. It simply took the commands
I gave it and asked, “What’s next?”
The Shoestring fits the intent of this class
perfectly. It is a great weekday sport flyer that
can be turned into a competitive race airplane
with some simple control surface-rate
changes and installing the APC 8 x 8E
propeller.
I plan to get a new one in October when
they come out. MA
—Lonnie Finch
Horizon Hobby/E-flite sponsored
the Electric Formula One (EF1) contest
The E-flite Shoestring ARF is
designed to be flown for sport or
Pylon racing. It looks anxious to
fly just sitting on the runway.
Although easy enough to operate
one-handed, the hatch is very secure.
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