Seagull Decathlon EP

Seagull Decathlon EP

Although Seagull kits are made in China, J. Perkins (UK distributor for the range) tell me that theyve worked very closely with the factory on this new EP series, which is why they’re especially pleased with it. We’ve chosen to test the 50 Decathlon first and I plan to tell you all about it very shortly, but not before Ive told you the price – £59.99. Not many pennies for a Solarfilm covered, laser-cut, ARTF model, is it? Anyway, park this for a moment and well return to the thought at the end.

HERITAGE YOU CAN TRUST
The old adage of not fixing something unless its broken applies to the EP range, which is based on the Seagull i.c. line-up. Accordingly, the Decathlon is joined by electric versions of the Extra 300, Spacewalker and PC-9, the only new design being the X-Ray 3D aerobat. All are of about 50 wingspan and retail for that magic £59.99.

Perkins were happy for us to review any of the models in the line-up so we picked the Extra 300 and the Decathlon. The Extra 300 review will be along soon but I was keen to fly the Decathlon simply because it made a pleasant change from the stacks and stacks of lightweight 3D Yaks, Edges and Extras, all desperately trying to attract our hobby budget. With a semi-symetrical wing section, low weight and punchy powertrain I figured there shouldn’t be any reason why I couldn’t throw the Decathlon around the sky whilst enjoying a little relaxing slow flight when the mood took me.

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BITS AND BOBS
You’ll forgive me resorting to the time-honoured reviewer’s cliché when I say that the package is typical ARTF well-made and nicely presented because it simply is. The fuselage structure is a work of art, a work of laser cut art in fact; supremely light, very strong and beautifully built. As you might expect, the wings and tail feathers follow the trend.

The Decathlon has been designed for 600 size electric motors or brushless equivalents. It’s obvious that the model has also been planned around the weight and size of a typical 3s Li-Po battery and, as such, squeezing in an 8 – 10 cell pack of NiMHs would undoubtedly add too much weight and compromise the performance. I really wouldn’t suggest doing this.

Micro servos pulling 1 – 2kg are the order of the day for this one (Hitec 55s or equivalent will do nicely), whilst any size and shape of receiver unit will sit happily in the cavernous fuselage space. Mind you, as is always the case, the lighter it is the better! 

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Seagull Decathlon
Seagull’s
instructions take the form of a photo-step booklet which, generally
speaking, is perfectly adequate, although a little more explanatory
text wouldnt have gone amiss at certain stages. Plug-in wings and
screw-on tail feathers suggest that the model has been designed to be
taken apart for storage or transportation, the useful travel carry-box
suggestion at the back of the manual being a more obvious pointer.

NUMBER TIME
I fitted the motor suggested by Perkins, i.e. one of their EnErG-Pro
3514/14 brushless outrunner units from the range that was tested by
Nigel Hawes in his October 2006 Fly Electric column. These super little
motors are supplied complete with a mount, nuts, bolts, and a prop
drive unit. A scan of the Perkins website revealed that the 3514/14
should pull around 35 amps on 11 x 7 or 9 x 6 props, so my Jeti 40 amp
controller looked just the job. Moreover, since the anticipated flying
weight would be around 32 – 44oz, and with the web figures suggesting
340 – 400 watts from the motor (depending on the prop used), I
calculated an acceptable ballpark figure eclipsing the 100 watts per lb
minimum margin thats often suggested for electric models.

CONSTRUCTION
The Decathlon doesnt take long to put together, in fact the relative
ease and speed of construction are a genuine reflection of the thought
and development that’s clearly gone into the model. A few squirts with
the cyano, a dab of epoxy, and she’s pretty much complete. In truth I
guess I should expand on that a little more, but really theres little
to comment on. The moving surfaces use cyano hinges whilst the wings
plug together with an aluminium tube. Wing bolt holes are pre-drilled
and the captive nuts pre-installed in the fuselage. Oh, and if you
can’t stand sticking in windows, you’ll be pleased to hear that the
canopy glazing is pre-fitted.

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Moving on, the spat and wheel section is a quick cyano job using wooden
wheel collets along with a plastic spat retainer, and the motor drops
into place with complete ease. Incidentally, motor installation uses a
mount which you won’t be surprised to learn is a precise fit with the
pre-drilled holes in the ply stand-off.

I encountered a tricky moment with the motor in that I found I couldnt
screw the outrunner to the mount as the shaft was protruding from the
wrong end. The motor had been supplied with a view to attaching the
mount to the front of the unit and not the rear, as is required for the
Decathlon. Clearly I would have to push the shaft through to the other
end… somehow! In the absence of motor instructions I chatted to
Perkins who guided me through the process which entailed removing the
shaft collet and shaft grub-screws, pulling the casing apart, then
tapping the shaft through to the other side with gentle-ish taps from a
wooden mallet. Anyway, the process proceeded smoothly and my
re-assembled motor was very soon ready to run.

Tail feather servos are housed just under the horizontal stabiliser and
with an aileron servo in each wing, some direct, slop-free control
response looked promising. The horns are laser-cut plastic pieces that
just require some help with cyano to fix ’em in place. As an aside,
although I religiously check these after every flight, theyve been
just fine so far. I did, however, discard the servo arm screw-lock
connectors which I really don’t like using in this application. Swing
clip retainers are far better although they do demand accurate wire
bending without a v-shaped adjuster mid-length.

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As a final flourish, to make me feel like Id engaged in some creative
modelling, I added some Solartrim covered, balsa wheel leg fairings.
These make the u/c legs look far better and the spats seem less like
two yellow eggs flying in close formation!

 

Seagull Decathlon
Right,
I was almost ready to hit the skies. My clamp ammeter showed the wooden
11 x 7 prop pulling 40 amps at full throttle, the plastic 11 x 7
reading a little less. As such I decided to prop-down to 9 x 6 just to
make life a little more comfortable for the 40 amp ESC.

The battery is strapped to a removable tray which slides into place
from the underside, just behind the nose. Since this area is exposed to
plenty of cooling air, I strapped the ESC just behind the motor.
Control throws were set to the test flight rates suggested, and the
model balanced just a little nose heavy by shifting the battery tray
forward.

FLIGHT
With such a low wing loading and plenty of power on tap it was no
surprise to see the Decathlon leap away from a hand-launch. The model
will take off from grass but the small wheels dictate that only the
very smoothest of surfaces will guarantee the absence of a broken spat
or some other mishap.

Some models feel just right from take off and Im pleased to say the
Decathlon is definitely one of them. A few clicks of trim soon had her
flying hands free and after that the model treated me to one of the
most enjoyable test flights Ive experienced for many years. Youll
find that she’s very difficult to stall and although the precise stall
speed will depend on the C of G location, with a slightly nose heavy
set-up I couldn’t achieve anything other than a gentle mushy nose drop.
In a strong wind and at the same C of G setting, she doesn’t do
anything at all!

The Decathlon is pretty sprightly even at the suggested starting rates
and theres plenty of power for loops and rolls, the latter being more
axial than I would have expected. Even with a slightly forward balance
inverted flight was easy to maintain with a touch of down elevator.
Sometimes a very slight amount of rudder is required to help start a
turn, especially when climbing out after a slow, low pass. Mind you,
this trait hasnt been significant enough to provoke me into mixing
rudder with aileron. She’s pretty snappy too, again, even with a
forward C of G – sticks in the corners will have her cavorting around
in a fashion sufficient to embarrass many purpose-designed aerobats.

Landings are a straight-forward undertaking, indeed I was surprised how
well the small wheels and spats coped with short grass. That said, I’m
sure normal length grass will induce a nose-over flourish at some stage
in the process. The model will float down perfectly on a calm day but
needs some throttle management to bring her in on windy ones, although
this would apply to most models of course. Oh, and it’s good to know
that she won’t drop a wing at any stage in the process.

Flight times are respectable but will depend on throttle management and
prop size. I found that 7 – 9 minutes of general flight on the 9 x 6
was easily achievable, although I always land with some amps in the
tank. This prop size seems just right for the model so to date I’ve
really not seen the need to change up, indeed the Decathlon will climb
vertically on the 9 x 6 for 5 – 10 seconds before losing its urge.
Clearly, propping-up should improve this a little.

As I say, those wheel spats will take some punishment in longer grass
where a conventional landing will be all but impossible, even at a slow
landing speed. Spat wheel clearance is pretty limited so although the
light wheels supplied are there for a purpose (i.e. theyre light)
fitting some larger, heavier items shouldnt compromise the performance
given the level of power on tap. A string of long-grass nose-over
landings eventually broke the internal ply u/c mounts, so it’s best to
beef these up with a little plywood at the construction stage. Unless,
of course, your patch is a bowling green!

PERFECTION?

Landing gear issues aside, the Seagull EP Decathlon is a delight,
theres no other word for it. Shes very well made, easy to assemble,
looks great and flies beautifully.

The Decathlon is big enough to be a viable everyday model for the club
flightline, yet small enough so that an affordable brushless propulsion
system will deliver a satisfying performance. The motor and battery
combination I’ve used is probably a little more powerful than necessary
but, as always, it’s better to have more grunt than less!

I suspect that some of the other models in the Seagull EP range will be
a little more sprightly and perhaps attuned to pure aerobatic and 3D
flight, but for a good, all-round satisfying sport aerobatic flying
performance combined with an attractive semi-scale appearance the
Decathlon is all you’ll need. You won’t need me to tell you that £59.99
is a sensational price.

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