Reveiw Super Pearl 202-E - 2012/07

At  rst glance, Don DeLoach’s
new E-36 electric FF design,
the Super Pearl 202-E, recalls
the small FF power models of the
past: constant-chord wing planform,
high pylon, and all-balsa wing and tail
construction. But it is not a rehash of
40-year-old plans. Designed speci cally
for the new E-36 rules that went into
effect in 2011, the model combines
proven construction techniques with
some new twists.
What is E-36? Like the popular P-30
Rubber event, E-36 was developed to
provide a high level of performance
with a minimum investment in
building time or  nancial outlay.
The new rules keep the 36-inch
span limit of the earlier E-36 rules,
but allow more modern motor and
battery technology. (The old rules
were restricted to brushed motors and
nickel-based cells; this offered lessthan-
exciting performance and had
limited participation.)
The new rules allow any type of
electric motor and either a two-cell
lithium battery or a six-cell nickel
battery. Gearing and folding propellers
are permitted, but auto surfaces are not.
The minimum weight is 120 grams
(roughly 41/4 ounces). As with P-30,
the E-36  ight maximum is two
minutes, making it a good small- eld
event. For the  rst three  ights, the
motor run is limited to 15 seconds. If
the  rst three  ights are maxes, then
the fourth  ight motor run is limited to
10 seconds. If that one is maxed, then
the motor run for the  fth and any
subsequent  ights is cut to 5 seconds.
These sensible rules keep models on
the  eld and prevent marathon  yoffs.
“The E-36 models are easy to max on
a 15-second motor run, marginal on
10 seconds, and not even close on 5
seconds,” said Don. “The 202-E gets
about 150 feet high on 5 seconds and
will do 70 seconds in neutral air. You
need good air to max the  fth round.”
Limiting the wingspan to 36 inches
eliminates the need for carbon-
 ber D-boxes and other advanced
construction techniques needed with
the high-aspect-ratio wings found in
events that limit wing area instead of
wingspan. A traditional balsa structure
will work  ne.
The typical E-36 design features a
wing chord of 51/2 to 6 inches and an
overall length of roughly 30 inches. The
 at-bottomed wing airfoils are typically
thick, allowing quick construction and
suf cient stiffness. Because no auto
surfaces (such as auto stabilizer or
auto rudder) are allowed, E-36 models
follow traditional gas model trim: a
spiral climb to the right controlled
by left thrust and washin on the right
main wing. The glide is usually to the
right, determined by stabilizer tilt.
Although Don designed the Super
Pearl 202-E late last summer, it has
already racked an impressive contest
record. Don and Dan Berry placed  rst
and second at the Southwest Regionals
in Eloy, Arizona, and Don and Randy
Reynolds placed  rst and second at the
Isaacson Winter Classic in Lost Hills,
California.
You can order the Super Pearl 202-
E directly from Don. It is available as
plans only or the plans and a short kit
of laser-cut ribs and other parts. As
with any short kit, you provide the
strip wood, sheet balsa for pylon sides
and rudder, covering, and hardware.
Strip wood and balsa sheet are
available at your local hobby shop, but
you will need to order the carbon-
 ber kite spar used for the fuselage.
Two are suggested on the plans: the
AVIA G-Force Skinny UL, available
from online kite suppliers such as
Goodwinds, or Stan Buddenbohm’s
tip-launch glider boom, available
directly from Stan. However, any 32-
inch or longer tapered carbon- ber kite
spar would work if it is in the 7-gram
weight range. Expect to pay roughly
$12, plus shipping.
You will also need to order the
motor, propeller, and additional
electronic equipment needed for
electric-powered FF.
First Impressions
The plans come as a single rolled
sheet measuring 24 x 40 inches. The
CAD-drawn plans are accurate and
include full-size drawings of all the
ribs. You could scratch-build the model
from the plans, but having laser-cut
parts is easier.
An advantage of CAD-drawn plans is
that they can easily be updated. In fact,
I noticed a few minor changes between
the plans dated August 2011, shown
in my February 2012 “FF Duration”
column, and the updated plans I
received in January of 2012.
The short kit includes three sheets
of 1/16-inch balsa containing the wing
and stabilizer ribs, triangular gussets,
and vertical webbing for the wing and
stabilizer main spars. A small sheet
of 1/16-inch plywood includes the
stabilizer mount, two discs for the
motor mount, and dihedral braces.
The laser cutting for both balsa and
plywood was clean and accurate; the
balsa parts came out easily with only
an occasional need for the knife, but it
took a little work to cut through the
small sections connecting the plywood
pieces to the sheet.
Setup
With any type of FF model, the most
important step is making sure that the
components are accurately aligned,
the CG is correct, and that all systems
work perfectly.
I began by installing the motor and
propeller, and fitting the ESC, timer,
and servo in the pylon. I temporarily
taped the pylon and battery in place,
and attached the wing and stabilizer.
By moving the pylon and battery
back and forth along the fuselage, I was
able to get the CG exactly as shown on
the plans. Then I epoxied the pylon to
the fuselage, making sure the pylon and
vertical stabilizer were aligned. Setting
the pylon upside down made this easy.
Next, I strapped the wing in
place and checked the alignment by
measuring from the rear of the fuselage
to both wingtips, making adjustments
until both measurements were equal.
On Dan Berry’s recommendation, I
added 1/16 x 1/4-inch basswood keys to
the underside of the LE and TE tight
against the wing mount. The keys will
ensure that the wing is on straight for
each flight.
The tightly stretched wing holddown
rubber bands slightly pulled
the TE down. I fixed this by adding
3/32-inch thick balsa strips to the top of
the wing saddle in the front and rear.
I sanded them to match the underside
center of the wing, giving full support.
At the back end, I cut out the
rudder tab, and then attached it with
two pieces of copper wire to allow
adjustment. The 14-gauge wire was too
thick to adjust easily, and impossible to
remove without breaking the tab.
After patching the vertical stabilizer,
I cut a piece of 1/16-inch balsa the same
size as the tab, sanded it to a wedge
shape, and glued it to the right rear of
the vertical stabilizer. Movable rudder
tabs are too easily knocked out of
position and too tempting to tweak.
For DT, I added a wire and brass tube
lever on the side of the pylon behind
the timer. The long arm runs forward,
where it is trapped underneath the
servo lever. The other end holds a
rubber band attached to the front end
of the monofilament DT line that runs
back to the stabilizer.
I practiced setting the timer, checking
motor run and DT times, and ensuring
that everything worked.
Flying
If you have experience flying a gas
model, the process of testing and flying
the Super Pearl 202-E will be familiar.
As with any locked-up, pylon-type
power model (gas or electric), adjusting
the model to fly safely and to its
maximum potential involves carefully
balancing controls so it flies itself, free
of any control from the ground.
Some adjustments, such as side- or
downthrust, CG location, and stabilizer
tilt, are more effective at low speed and
become less effective at higher speeds.
Rudder offset, wing wash, and decalage
are more effective at high speeds and
less effective at low speeds.
On the Super Pearl 202-E, the left
thrust offset helps prevent the model
from hooking to the right on launch.
Once airspeed builds, the right rudder
tab produces right turn in the climb,
while the washin on the right main
wing panel produces the left roll
needed to balance the right turn, giving
the desired corkscrew climb.
Decalage controls the climb angle.
Too much decalage and the model
will loop; too little and the climb will
be flat. For a model without an auto
stabilizer, such as the 202-E, the climb
angle must be optimized by changing
the decalage. This is easy on this model
thanks to the adjustment screw on the
stabilizer.
Short motor run flights with the DT
set a few seconds after the motor stops
allow climb adjustments to be made
safely. Gradually lengthen the motor
run with repeated test flights until the
climb and recovery are right, then the
glide can be optimized.
In the glide, the right stabilizer tilt
becomes more effective and is used to
adjust the diameter of the glide circle.
Slight CG adjustments are used to
fine-tune the glide angle. The external
battery makes this easy, but be sure to
mark the final location on the fuselage.
Hand-gliding my Super Pearl 202-E
showed it needed much more stabilizer
tilt then I had built in. It ended up with
a 3/64-inch shim on the right side of the
stabilizer mount to get a reasonable
amount of glide turn.
Because increasing the tilt raised the
stabilizer’s LE, effectively decreasing
decalage, I had to raise the stabilizer’s
TE by half the amount of the shim
thickness. Instead of gluing in a shim
that would leave the center of the
stabilizer unsupported, I added a
basswood wedge the full width of the
stabilizer mount.
The purpose of hand gliding a
locked-up power model is not to get
the glide perfect, but to make sure that
the glide is safe enough to begin power
testing. The model should have a
definite right glide turn without a hint
of a stall or dive.
Power testing my 202-E was delayed
because of weather and the lack of a
nearby flying site; however, Dan Berry
and Randy Reynolds offered their
experiences with trimming.
“In the desert, I removed the prop
for glide tests; with the CG as drawn,
I got it gliding,” said Dan. For the first
power flight, Dan set the motor run
for five seconds, started the timer, and
counted two seconds before launching.
“It went up and right safely. For the
second flight I moved the battery back
and lowered the stab. Steeper climb
with less right turn was the result. I
lowered the stab some more, moved
the battery further back and flew
again—nice steep pattern that wanted a
bit of right tab. I added some right tab
and that’s what it has now. It’s a Pearl.
It shouldn’t need a lot of trim flights
if warps are reasonable and it gets
assembled sort of square,” said Dan.
Randy echoed the need to keep
the motor run at approximately three
seconds during early trimming. “The
five-second motor run is a bit long,” said
Randy. “These little guys can move just
as well as a hot TeeDee 1/2A ship and
they can misbehave in five seconds.”
Launch angle is also important. “I
always launch too shallow and have
been coached to go up to 70° plus,”
Randy said. “I would suggest you
practice a bit in the shop because it is
a lot steeper than you might think. You
also want to hold the model in a slight
right bank at launch. In other words, it
is at the attitude that the ship will be in
the helical climb.”
Dan cautioned, “When flying electric
with an ESC, you must let the motor
run for at least one second before
launching. If you have a low or bad
battery, the ESC will shut down the
motor. Like any gas plane, when the
motor quits 10 to 20 feet up, things
are ugly.”
Conclusion
The Super Pearl 202-E provides a
FF modeler some building experience
with this easy-to-build electricpowered
aircraft. The modified Union
Jack construction, coupled with the
9%-thick airfoil, produces a stiff wing
that should withstand the rigors of
flying. Using a tapered carbon-fiber
tube made fuselage construction faster,
and probably lighter, than that of a
conventional balsa box.
The builder must supply strip wood,
sheet balsa, hardware, and, in this case,
the carbon-fiber boom. I had most of
the balsa on hand and only needed to
pick up a few pieces of strip wood at
the local hobby shop. The laser-cut ribs
and other parts were provided.
Although the model went together
in a few days, the process of tracking
down, ordering, and receiving some of
the electronic gear took several weeks.
If something is out of stock, the wait
can be even longer, so it pays to plan
ahead. If you are new to electric, allow
yourself time to become familiar with
setting and operating the timer and
charging the battery.
The Super Pearl 202-E kit is
popular and there is a growing body of
information about building and flying
this design available on the Internet. The
E-36 event is also becoming increasingly
popular, offering the fast climb of gas
without the mess and the challenge of
rubber, and without the large amount of
ground-support equipment.
“I think you’ll like E-36, as there is a
lot of flying and a minimum of fuss at
the field,” said Randy. “Not that there
isn’t a lot to learn, but other than a
Gollywock, it’s the most fun you can
have at the flying field.”

At  rst glance, Don DeLoach’s
new E-36 electric FF design,
the Super Pearl 202-E, recalls
the small FF power models of the
past: constant-chord wing planform,
high pylon, and all-balsa wing and tail
construction. But it is not a rehash of
40-year-old plans. Designed speci cally
for the new E-36 rules that went into
effect in 2011, the model combines
proven construction techniques with
some new twists.
What is E-36? Like the popular P-30
Rubber event, E-36 was developed to
provide a high level of performance
with a minimum investment in
building time or  nancial outlay.
The new rules keep the 36-inch
span limit of the earlier E-36 rules,
but allow more modern motor and
battery technology. (The old rules
were restricted to brushed motors and
nickel-based cells; this offered lessthan-
exciting performance and had
limited participation.)
The new rules allow any type of
electric motor and either a two-cell
lithium battery or a six-cell nickel
battery. Gearing and folding propellers
are permitted, but auto surfaces are not.
The minimum weight is 120 grams
(roughly 41/4 ounces). As with P-30,
the E-36  ight maximum is two
minutes, making it a good small- eld
event. For the  rst three  ights, the
motor run is limited to 15 seconds. If
the  rst three  ights are maxes, then
the fourth  ight motor run is limited to
10 seconds. If that one is maxed, then
the motor run for the  fth and any
subsequent  ights is cut to 5 seconds.
These sensible rules keep models on
the  eld and prevent marathon  yoffs.
“The E-36 models are easy to max on
a 15-second motor run, marginal on
10 seconds, and not even close on 5
seconds,” said Don. “The 202-E gets
about 150 feet high on 5 seconds and
will do 70 seconds in neutral air. You
need good air to max the  fth round.”
Limiting the wingspan to 36 inches
eliminates the need for carbon-
 ber D-boxes and other advanced
construction techniques needed with
the high-aspect-ratio wings found in
events that limit wing area instead of
wingspan. A traditional balsa structure
will work  ne.
The typical E-36 design features a
wing chord of 51/2 to 6 inches and an
overall length of roughly 30 inches. The
 at-bottomed wing airfoils are typically
thick, allowing quick construction and
suf cient stiffness. Because no auto
surfaces (such as auto stabilizer or
auto rudder) are allowed, E-36 models
follow traditional gas model trim: a
spiral climb to the right controlled
by left thrust and washin on the right
main wing. The glide is usually to the
right, determined by stabilizer tilt.
Although Don designed the Super
Pearl 202-E late last summer, it has
already racked an impressive contest
record. Don and Dan Berry placed  rst
and second at the Southwest Regionals
in Eloy, Arizona, and Don and Randy
Reynolds placed  rst and second at the
Isaacson Winter Classic in Lost Hills,
California.
You can order the Super Pearl 202-
E directly from Don. It is available as
plans only or the plans and a short kit
of laser-cut ribs and other parts. As
with any short kit, you provide the
strip wood, sheet balsa for pylon sides
and rudder, covering, and hardware.
Strip wood and balsa sheet are
available at your local hobby shop, but
you will need to order the carbon-
 ber kite spar used for the fuselage.
Two are suggested on the plans: the
AVIA G-Force Skinny UL, available
from online kite suppliers such as
Goodwinds, or Stan Buddenbohm’s
tip-launch glider boom, available
directly from Stan. However, any 32-
inch or longer tapered carbon- ber kite
spar would work if it is in the 7-gram
weight range. Expect to pay roughly
$12, plus shipping.
You will also need to order the
motor, propeller, and additional
electronic equipment needed for
electric-powered FF.
First Impressions
The plans come as a single rolled
sheet measuring 24 x 40 inches. The
CAD-drawn plans are accurate and
include full-size drawings of all the
ribs. You could scratch-build the model
from the plans, but having laser-cut
parts is easier.
An advantage of CAD-drawn plans is
that they can easily be updated. In fact,
I noticed a few minor changes between
the plans dated August 2011, shown
in my February 2012 “FF Duration”
column, and the updated plans I
received in January of 2012.
The short kit includes three sheets
of 1/16-inch balsa containing the wing
and stabilizer ribs, triangular gussets,
and vertical webbing for the wing and
stabilizer main spars. A small sheet
of 1/16-inch plywood includes the
stabilizer mount, two discs for the
motor mount, and dihedral braces.
The laser cutting for both balsa and
plywood was clean and accurate; the
balsa parts came out easily with only
an occasional need for the knife, but it
took a little work to cut through the
small sections connecting the plywood
pieces to the sheet.
Setup
With any type of FF model, the most
important step is making sure that the
components are accurately aligned,
the CG is correct, and that all systems
work perfectly.
I began by installing the motor and
propeller, and fitting the ESC, timer,
and servo in the pylon. I temporarily
taped the pylon and battery in place,
and attached the wing and stabilizer.
By moving the pylon and battery
back and forth along the fuselage, I was
able to get the CG exactly as shown on
the plans. Then I epoxied the pylon to
the fuselage, making sure the pylon and
vertical stabilizer were aligned. Setting
the pylon upside down made this easy.
Next, I strapped the wing in
place and checked the alignment by
measuring from the rear of the fuselage
to both wingtips, making adjustments
until both measurements were equal.
On Dan Berry’s recommendation, I
added 1/16 x 1/4-inch basswood keys to
the underside of the LE and TE tight
against the wing mount. The keys will
ensure that the wing is on straight for
each flight.
The tightly stretched wing holddown
rubber bands slightly pulled
the TE down. I fixed this by adding
3/32-inch thick balsa strips to the top of
the wing saddle in the front and rear.
I sanded them to match the underside
center of the wing, giving full support.
At the back end, I cut out the
rudder tab, and then attached it with
two pieces of copper wire to allow
adjustment. The 14-gauge wire was too
thick to adjust easily, and impossible to
remove without breaking the tab.
After patching the vertical stabilizer,
I cut a piece of 1/16-inch balsa the same
size as the tab, sanded it to a wedge
shape, and glued it to the right rear of
the vertical stabilizer. Movable rudder
tabs are too easily knocked out of
position and too tempting to tweak.
For DT, I added a wire and brass tube
lever on the side of the pylon behind
the timer. The long arm runs forward,
where it is trapped underneath the
servo lever. The other end holds a
rubber band attached to the front end
of the monofilament DT line that runs
back to the stabilizer.
I practiced setting the timer, checking
motor run and DT times, and ensuring
that everything worked.
Flying
If you have experience flying a gas
model, the process of testing and flying
the Super Pearl 202-E will be familiar.
As with any locked-up, pylon-type
power model (gas or electric), adjusting
the model to fly safely and to its
maximum potential involves carefully
balancing controls so it flies itself, free
of any control from the ground.
Some adjustments, such as side- or
downthrust, CG location, and stabilizer
tilt, are more effective at low speed and
become less effective at higher speeds.
Rudder offset, wing wash, and decalage
are more effective at high speeds and
less effective at low speeds.
On the Super Pearl 202-E, the left
thrust offset helps prevent the model
from hooking to the right on launch.
Once airspeed builds, the right rudder
tab produces right turn in the climb,
while the washin on the right main
wing panel produces the left roll
needed to balance the right turn, giving
the desired corkscrew climb.
Decalage controls the climb angle.
Too much decalage and the model
will loop; too little and the climb will
be flat. For a model without an auto
stabilizer, such as the 202-E, the climb
angle must be optimized by changing
the decalage. This is easy on this model
thanks to the adjustment screw on the
stabilizer.
Short motor run flights with the DT
set a few seconds after the motor stops
allow climb adjustments to be made
safely. Gradually lengthen the motor
run with repeated test flights until the
climb and recovery are right, then the
glide can be optimized.
In the glide, the right stabilizer tilt
becomes more effective and is used to
adjust the diameter of the glide circle.
Slight CG adjustments are used to
fine-tune the glide angle. The external
battery makes this easy, but be sure to
mark the final location on the fuselage.
Hand-gliding my Super Pearl 202-E
showed it needed much more stabilizer
tilt then I had built in. It ended up with
a 3/64-inch shim on the right side of the
stabilizer mount to get a reasonable
amount of glide turn.
Because increasing the tilt raised the
stabilizer’s LE, effectively decreasing
decalage, I had to raise the stabilizer’s
TE by half the amount of the shim
thickness. Instead of gluing in a shim
that would leave the center of the
stabilizer unsupported, I added a
basswood wedge the full width of the
stabilizer mount.
The purpose of hand gliding a
locked-up power model is not to get
the glide perfect, but to make sure that
the glide is safe enough to begin power
testing. The model should have a
definite right glide turn without a hint
of a stall or dive.
Power testing my 202-E was delayed
because of weather and the lack of a
nearby flying site; however, Dan Berry
and Randy Reynolds offered their
experiences with trimming.
“In the desert, I removed the prop
for glide tests; with the CG as drawn,
I got it gliding,” said Dan. For the first
power flight, Dan set the motor run
for five seconds, started the timer, and
counted two seconds before launching.
“It went up and right safely. For the
second flight I moved the battery back
and lowered the stab. Steeper climb
with less right turn was the result. I
lowered the stab some more, moved
the battery further back and flew
again—nice steep pattern that wanted a
bit of right tab. I added some right tab
and that’s what it has now. It’s a Pearl.
It shouldn’t need a lot of trim flights
if warps are reasonable and it gets
assembled sort of square,” said Dan.
Randy echoed the need to keep
the motor run at approximately three
seconds during early trimming. “The
five-second motor run is a bit long,” said
Randy. “These little guys can move just
as well as a hot TeeDee 1/2A ship and
they can misbehave in five seconds.”
Launch angle is also important. “I
always launch too shallow and have
been coached to go up to 70° plus,”
Randy said. “I would suggest you
practice a bit in the shop because it is
a lot steeper than you might think. You
also want to hold the model in a slight
right bank at launch. In other words, it
is at the attitude that the ship will be in
the helical climb.”
Dan cautioned, “When flying electric
with an ESC, you must let the motor
run for at least one second before
launching. If you have a low or bad
battery, the ESC will shut down the
motor. Like any gas plane, when the
motor quits 10 to 20 feet up, things
are ugly.”
Conclusion
The Super Pearl 202-E provides a
FF modeler some building experience
with this easy-to-build electricpowered
aircraft. The modified Union
Jack construction, coupled with the
9%-thick airfoil, produces a stiff wing
that should withstand the rigors of
flying. Using a tapered carbon-fiber
tube made fuselage construction faster,
and probably lighter, than that of a
conventional balsa box.
The builder must supply strip wood,
sheet balsa, hardware, and, in this case,
the carbon-fiber boom. I had most of
the balsa on hand and only needed to
pick up a few pieces of strip wood at
the local hobby shop. The laser-cut ribs
and other parts were provided.
Although the model went together
in a few days, the process of tracking
down, ordering, and receiving some of
the electronic gear took several weeks.
If something is out of stock, the wait
can be even longer, so it pays to plan
ahead. If you are new to electric, allow
yourself time to become familiar with
setting and operating the timer and
charging the battery.
The Super Pearl 202-E kit is
popular and there is a growing body of
information about building and flying
this design available on the Internet. The
E-36 event is also becoming increasingly
popular, offering the fast climb of gas
without the mess and the challenge of
rubber, and without the large amount of
ground-support equipment.
“I think you’ll like E-36, as there is a
lot of flying and a minimum of fuss at
the field,” said Randy. “Not that there
isn’t a lot to learn, but other than a
Gollywock, it’s the most fun you can
have at the flying field.”