The
fuselage and parts were very well secured in the box using plastic
bags, custom compartments, and tape. There were no loose parts
to get damaged. Two manuals were included, one for the HyperFlow
fan assembly and the other for the model assembly. One of the
decal sheets provided was for scale markings and the other for
promotional branding.
The
control surfaces were pre-assembled including the horns and
quick links. All the control horns were additionally protected
by custom foam pockets that could easily be removed after shipping.
I
was surprised to see servo extensions and a motor included in
the kit. This was a nice added touch by Great Planes!
A
closer look at the fuselage revealed several design details.
The AeroCell foam made the fuselage very light but not delicate.
The surface did not appear prone to dents or rash. The detailed
canopy was magnetically secured for easy access to the F-20's
battery compartment. Likewise, the aft hatch that secures the
HyperFlow DF could be easily removed by sliding it back and
then lifting out.
Strings
were pre-placed inside the fuselage to allow easy routing of
the servo control wire extensions.
The
air intake ducts and exhaust area were optimized to provide
maximum speed and efficiency to the F-20.
I
used the following components to complete my F-20 Tigershark.
-
Great
Planes Silver Series 45A
Brushless ESC
-
-
Futaba
R617FS
2.4GHz FASST 7-Channel Receiver
-
Three
Futaba S3114
Micro High-Torque Servos
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Assembly:
The
Tigershark assembly begins with gluing a carbon rod into a channel
on the bottom side, followed by the wing halves and a foam filler
piece. Since Aerocell foam loves CA and kicker, this is a quick
assembly.
Likewise,
the horizontal tail piece is glued to the bottom of the fuselage
into a custom channel. The piece is held forward in the channel
to allow for proper operation of the pre-assembled elevator joiner.
Before
you know it, the model looks like an F-20 Tigershark!
Power
System:
Assembling
the HyperFlow fan unit was fairly straightforward. The unit allows
for several size motors so I needed to trim away the alignment
guides for my AMMO 24mm motor. This job was made much easier with
a Dremel tool sanding barrel.
The
spinner is left off for this model and the stator extension is
pressed into place onto the back of the ducted fan housing. The
extension is secured with a few drops of medium CA. Locktite thread
locker was applied to all screws on this part of the assembly.
The
instructions recommend testing the fan unit prior to gluing it
into the fuselage. Initially, I was disappointed when the pre-installed
bullet connectors on the AMMO motor did not fit properly on the
Silver Series 45A ESC connectors. I then discovered that Great
Planes had indeed supplied adapter cables to extend the motor
wires and properly convert the different sized bullet connectors.
The
rotor had a slight area of rubbing onto the fan unit but I knew
that a few seconds of running this soft plastic would correct
the issue. When I ran the system up on my bench, I was happy with
the excellent amount of air getting pushed through the fan. This
power system should work very nicely with the F-20 Tigershark.
DF
Mounting:
Note
that I extended the battery wires on my ESC before I found the
motor wire extensions in the kit so this step is not needed. Great
Planes has provided extensions for the three motor wires that
also act as size converters for the different bullet connectors
on the ESC and AMMO motor. Three pieces of shrink tubing are also
supplied to cover the connectors at the joint.
The
tested ducted fan unit is secured in the fuselage using glue or
servo tape. I used a small amount of 5-minute epoxy.
Note
that I color-coded my black wires on the ESC with paint so that
I did not need to re-test the power system for proper rotor rotation.
I also added two small cable ties to secure the motor and ESC
wires from vibrating during flight.
The
intake ducting looked like it was designed very well and should
be quite efficient. Even the combiner area of the two intake ducts
formed into a round foam rod that actually plugged into the rotor
center. Since the foam is soft, the first second or so of the
motor running will seat the rotor properly if there was any rubbing.
I cut about 1/4" of the foam rod off for a proper fit without
excessive rubbing on the rotor.
Servo
Mounting:
The
Futaba S3114 servos mounted in the custom pockets using a small
amount of medium CA. The servo leads are tied to the strings and
then routed back towards the DF unit. The leads are then connected
to the supplied extension and Y-harness before their final routing
through the fuselage to the battery bay.
I
used a small amount of medium CA to attach the plastic extension
connector to the foam side and neatly routed the wires. Although
heat shrink tubing is supplied to secure the servo leads in the
extensions, I used some green 3M masking tape. I prefer not to
use a heat gun near a foam model. Before fitting the motor hatch
to the fuselage, I removed the 72MHz antenna tube since it was
not needed. The hatch has plywood hooks and strong magnets to
secure it in place.
Control
Rods:
The
control rods were any easy install since they were pre-bent and
cut to length. The Z-bend went in the center servo hole and the
straight end into the pre-installed quick link. I added some Locktite
to keep the screws secure.
The
aileron control surfaces were aligned to meet the fuselage flat
bottom and the elevator to center in the stabilizer. The main
wing appears to be flat on the bottom and the stabilizers are
symmetrical airfoils. Once the rods are installed, the servo covers
simply press into place after peeling the paper off the pre-applied
double-sided tape.
Tail:
The
vertical stab presses into place after applying some medium CA
to the base. The tail cone can either be taped in place or held
by a few drops of CA. I used some CA for a cleaner look.
CG:
The
CG lines were marked at the recommended setting of 3-3/4"
back from the leading edge (LE) of the wing at the fuselage. Don't
use the air intake duct as it is 1/4" forward.
The
battery position was determined, as shown, after the first few
flights.
Test
Stand:
The
supplied display stand assembled easily with 5-minute epoxy. You
can also use white glue buy not CA. Another nice touch by Great
Planes!
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F-20
Tigershark 
