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Specifications
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Wingspan
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42"
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Wing Chord
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11" at root, tapering to 6" at the tips
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Wing Airfoil
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Under Cambered 'Coffee Can' airfoil
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Weight
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5.9 oz. plus battery
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Radio
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GWS R-4P receiver, Hitec Eclipse 7 transmitter
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Servos
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2 GWS Naro-HP BB (included)
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Speed Control
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Castle Creations Pixie-7p
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Motor/Prop
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GWS-A/10x4.7 or GWS-S1/8x6
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Available From
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Ace Sim R/C
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Introduction
When I first saw the Carbon Falcon announced here on the E-zone I thought it looked very
interesting. After reading about it on the Ace Sim R/C website I considered it firmly entrenched
on my want list. A couple of months after first learning about this plane I was lucky enough to
see one that a clubmate of mine had purchased. He had not set it up yet, but it looked even
better in person then it did on-line. At this point I knew this was a model I wanted to get
quickly. Fortunately for me only a few days after seeing the Carbon Falcon in person, the
opportunity to review it for the E-zone presented itself, and I couldn't respond quick enough.
Kit Contents
The kit arrived in less than a week shipped priority US mail. The packaging was sufficent to
prevent any shipping damage and my plane arrived with no damage.
To call the Carbon Falcon an ARF is really selling it short. The level of prefabrication in this
kit really deserves to have it labeled as an RTF model. My kit was sent with the servos
installed. This is done to insure that the correct servos are used and the linkages are set up
correctly. If the cost of the included servos is considered when you look at the price of the
plane, the airframe is reasonably priced. The servos that are installed are GWS Naro-HP BB
servos which have torque rating of 31 ounces which is very high considering the weight and size
of the servos. I have had good luck with these servos in a 2-meter sailplane before so I was
happy to see them come with the Carbon Falcon.
The remaining sub-assemblies of the airframe came completely assembled and are shipped as you
would store them when transporting the plane. Since there is so little assembly to be done, the
accessory package, while complete including spare hardware, contains very few parts aside from
the extra servo horns and screws from the included servos. You do get a nice piece of clear
adhesive backed repair fabric, and a colored accent strip which comes in a color of your own
choosing. My main wing came in yellow with a red accent strip, but many color combinations are
available.
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Main Parts
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Accessories
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For electronics I chose a GWS R-4P single conversion receiver and Castle Creations Pixie 7-P
ESC. For motors I installed a GWS IPS-A (Lite-Stik motor) with a 10x4.7" propeller. I also have
used a 9x7" prop on this gearbox, and a 8x6" prop on the GWS IPS-S1 gearbox. Batteries used for
testing included 7- and 8-cell 280 NiMh, 2x830 Li-Ion "Qualcom" and several different Lithium
Polymer 2-cell series packs. Lithium Polymer packs required far forward placement to balance the
model but worked fine, especially the 2x1020 Kokam packs.
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Equipment
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Assembly
How long did it take you to build your last ARF? Four hours? Ten? More? The total time for me
from opening the box to having the Carbon Falcon ready to maiden was 90 minutes--and that
included taking notes and more than 30 photographs of the process. If I had to do it without
photographing, I could have easily finished in 45 minutes or less. The entire assembly
can be done at your flying field since the only tools used are a pair of scissors to cut the
accent strip. The manual is excellent and loaded with photographs describing each step in
detail. I am showing the general procedure I followed since I added a couple of my own personal
touches to the build.
First the manual recommends to hooking up all of your electronics and checking the centering of
the installed servos. Although the warperons are unusual in design, they use the normal flying
wing elevon mix. My servo arms seemed fine at zero trim on my transmitter. I double checked the
torque on all the servo mounting screws to make sure that nothing loosened during shipping.
In step two I attached my receiver to the center section with the provided elastic bands. It is
recommended to wrap your receiver in foam rubber. It took me a while to find a solution for this
step. Most foam rubber will be bulky where it overlaps, so I took a mini paint roller, and
stripped the foam from it. This gave me a perfect tube with one open end in which to stuff my
receiver and as a nice coincidence the color also matched my wing's fabric. Once the foam tube
was removed from the roller I inserted my receiver, trimmed the foam to length and strapped the
foam-coated receiver to the center fuselage section. This resulted in a clean installation that
provides excellent protection for my receiver.
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Next up was to mount the speed control. The manual suggests mounting the ESC on top of the
servos. Since the fuselage stick is upside down, this will be the underside in flight. To keep
airflow to the ESC, I attached it to the servos with another elastic band. Velcro or servo tape
also would work well here. For good measure I also used a miniature zip-tie to secure the motor
lead from the ESC to the rear of the center section. This makes motor swaps trivial, which is
important for a plane that will be disassembled when traveling or when stored. The motor
installation is saved for a later step, after the wing is attached.
Before the wing is attached to the carbon fiber center section the manual suggests applying the
colored trim strip. I would have preferred to have a larger piece of contrasting color to allow
for more creative markings, but I also think that keeping the trim strip a modest size helps
keep the weight down, which is always beneficial for a parkflyer. After playing with several
ideas, I fell back to the color scheme shown in the manual which was better than anything I
could come up with on my own. The center markings do help considerably with orientation of the
plane in flight.
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After I applied the markings to the wing, I was ready to assemble the plane. This step took
about two minutes and was easier to do than to describe. I attached the center section at the
rear of the wing with an elastic that wrapped around the motor mounting stick and attached to
the cloth at two clips on either side of the center. This rear elastic band should be quite
loose so the wing can warp properly. Originally I had this too tight, and the servos bound when
I tried to test the wing warping. The nose of the center section has two ears that slip into
pockets in the wing's leading edge. These ears, which are made up of a soft, rubber tubing, will
accept the leading edge carbon fiber tubes. From this point on the center section stays attached
to the wing, even when the plane is broken down for storage.
Once the center was secured, each of the arm frames was inserted into the wing from the wingtip
through the pocket in the leading edge. The arm frames start out completely folded up, but part
of each frame is unfolded as it passes through an opening in the wing's leading edge pocket.
This allows the frame to unfold and attach to both the servo and the wingtip's trailing edge.
Getting all of the carbon fiber rods inserted into the center section was tricky at first, but
after doing it a few times it has became quite routine. Once each side was attached, I connected
the servo arms with the snap-on hardware installed by the manufacturer. The motor slid on the
mount and was connected to the ESC lead.
Radio Setup, Balance and Trimming
As I mentioned before, the warperons on this plane use normal flying wing elevon mixing. Since
the warperon concept is so unusual, I took this video of the warperons:
Balance is very important on flying wings, and even more so on for under cambered ones. The
Carbon Falcon's leading edge is marked indicating where to hold it to balance it. These marked
points work well, but I have found that the wing flies best when the nose is pointed up 15-20
degrees, and the rear, reflexed portion of the warperons are parallel to the ground. This is a
little different from what modelers are used to when balancing a plane's CG. The photo below
shows the plane in a nose heavy situation, but illustrates the proper way to hold the plane and
use the provided marks. To achieve the proper balance point the battery is moved forward and
backward along the center section. This is relatively easy to do since the battery is held in
place with only a couple of elastic bands.
Once I balanced the plane, I folded it back up in preparation for my next trip to the flying
field. With a couple of batteries and the plane in one hand and my transmitter in the other
there's not much of a load to carry. The whole setup fit easily in the front seat of my car.
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Testing CG
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Ready to go!
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Flying
I finished the build just about dusk so I didn't have time to make it to the field for my maiden
flight. Luckily for me, the front yard of my house is a good sized area, about the same size as
a baseball infield. I decided to flip on the floodlights and get the plane trimmed out. I didn't
expect to do much flying in the small area, but I figured I could at least get the CG dialed in.
My first couple of hand launches resulted in gentle glides to the ground even under nearly full
throttle. This was because I had started way too nose-heavy, as shown in the photos above. I
gradually moved the battery back until I was getting good control authority and an acceptable
climb rate.
The first thing that I noticed is that the Carbon Falcon was able to fly much faster than I
expected. Since I hadn't become comfortable with the slow-flying performance of the plane, I
sped about my front yard at nearly full throttle for the first couple of flights. Even at speed
I found that the wing was plenty maneuverable to keep me out of the trees even in my front yard.
My biggest problem was flying out of the lighted area. Satisfied with the trim, I landed the
plane and folded it up until I could do some proper daylight flying.
The next chance I got to fly was a few days later in some light wind, about 5-10 mph. I started
out with a 10"x4.7" prop on the GWS IPS-A powerplant. While that was acceptable, switching to
the 9"x7" prop provided the additional speed I needed to fly in the wind. In a large area with
plenty of light, flying the Carbon Falcon was actually quite easy. The best thing was flying low
passes right in front of me, but I was also got couple of loops out of the wing with an
appropriate dive. After only a couple of flights I was comfortable enough with the flying
characteristics of the plane to get this movie. It's important to note that hand catching the
wing is risk-free since the prop is in the back and the leading edges are strong enough to not
break even, with the most ham-fisted of catches like the one in the video:
After a couple more sessions outdoors, I also successfully tried a Dymond plastic folding
parkflyer prop, which I estimate at about 8"x6" as well as a GWS 8"x6" fixed prop. Both of these
were used on a GWS IPS-S1 motor/gearbox. Both flew the Carbon Falcon well, but I prefer the
fixed prop, which seems to perform slightly better. The folding prop does increase the Falcon's
glide, but with the under cambered wing, exposed wires and carbon fiber supports, the Falcon
doesn't really truly thermal. I got some extended glides with the help of some lift, but it
would take a very strong 'hat sucker' thermal to soar this plane. Then again, that's really not
what the plane's designed for. Here is a short video which should give you an idea of the glide
path of the plane. This video was taken at dusk and ends with a hand catch:
Since I am a member of the Boston Micronauts I
get the chance to fly indoors each month, year round. The next meeting after I had the Carbon
Falcon built, I brought it to our indoor fly for 'show and tell'. It didn't take much
encouragement from the other members before I was convinced to give a demo of the plane indoors.
Our flying location is small -- a standard basketball court with very little additional space.
Our flight line is actually the court's boundary line. I went ahead and put a light pack on the
plane and the 10"x4.7" prop and IPS-A powerplant. I gave the Carbon Falcon a hand launch,
expecting to have to be quick on the sticks. However, by flying with a slightly nose-up attitude
I was able to slow the plane down nicely and fly both circuits and figure-eight patterns in the
tiny gymnasium. In an indoor soccer arena or similar larger facility, the Carbon Falcon would be
an excellent choice for indoor flying. It's durability for the occasional unexpected collision
is very good. So far I have crashed the plane into the walls of our gym about a dozen times
without a need for any repairs. As a side note, the meeting after this one, I helped four fellow
Micronauts set up or trim their Falcons. Many people who have seen or flown my Falcon have
expressed a strong interest in owning one and several of those have gone ahead and purchased
them.
Conclusion
The Carbon Falcon is a durable and highly portable parkflyer ARF that can be set up in well
under an hour. It flies well with a variety of powerplants in a variety of conditions, including
indoors and outdoors in moderate wind. This plane is my primary parkflyer due to it's
reliability and transportability. I highly recommend it to anyone looking for a durable and
convenient parkflyer or a plane to take on vacations or trips.
The only improvement I would recommend would be to affix a Velcro battery mount once you have a
good idea of where you like your battery packs mounted. This prevents the battery pack from
sliding around in flight on on the occasional rough landing.
Aug 29, 2003, 08:02 AM
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