You know the feeling, the
competition season is over, it's a dark, wet and miserable winters evening and you're
wondering what you are going to do for the next few months. I had to decide what model I
was going to fly the following season after a pretty good 2000; by my standards fourth in
the UK F3B A league is good season!
I needed to obtain the chosen
model, assemble it and trim to competition level as soon as possible. As I dozed
contemplating my next important move I had a vision of a tall, fairly well-built gent,
with what appeared to be a glowing cranium (it was probably his halo!), emerging from the
mist and fog. Across his brow was printed ED. Weird!
On waking up from this nightmare I
switched on my PC and was confronted with a message from our esteemed Editor asking if
Steve and I would be interested in doing a review of the new Ellipse 4 from Jaro Muller.
During our search for new models we
had been looking at the progress of the new Ellipse 4 and it appeared that the early
versions had proved to be lacking in torsional strength due to an attempt to reduce the
weight of the model. This was to be achieved by making the D box leading edge very strong
with the rest of the wing of a much lighter construction. It seems that this did not work
out in practice and Jaro had to revert to a normal construction for the wing.
This approach has to be commended
as it proves that Jaro is happy to try new ideas to improve the performance of his models
as can be seen with most of his previous models. The Ellipse 1 was probably the first
commercially available all moulded model. I have just parted with my nine-year-old
version, which was still in very good order. So much so that Steve used it to win the last
F3B competition of the 2000 season and in the process did a couple of speed runs of just
over 16 seconds.
First Impressions
The model arrived in June, which
meant that it would be very difficult to fly it in the League events of 2001. The only
concession we had to make was to accept the model in whatever colour was available. No
problem. It duly arrived in standard white upper surfaces and fuselage, with the under
surfaces in red .The same as my old Ellipse 1.
The model arrived very well packed
in two cardboard boxes, one for the one-piece V tail and one for the rest of the bits and
pieces such as two wing halves, one fuselage, one nose cone, one wing joiner and a bag of
hardware etc.
The initial impression was that
everything was up to the standard expected from Jaro. The surface finish was perfect, with
no blemishes whatsoever. Further inspection showed that the attention to detail was
probably the best that I have seen on any model. The wing and tail hinging was superb with
no stiffness to speak of and the mountings for the control surface horns were a joy to
behold. The fit of the nose cone and tail were also perfect.
A Closer Inspection
After the initial inspection it was
down to detail. The fuselage is the same as that used on the Escape and appears to be made
from two mouldings that include the wing and tail mounting. The inner nose section is a
separate moulding that comes ready fixed in to the main body. This nose section also
includes a moulded in ballast tube with access from underneath. The ballast is secured by
means of a large knurled screw. I understand that ballast is available with the model,
although I did not get any with the review model.
The nose section also has a built
in nose weight compartment with access via a countersunk Allen screw. This screw is quite
small at about 3 mm diameter. I assume that you would normally use lead shot in this
compartment but as I did not have any I simply used small slivers of lead fed into the
hole. Also in this area are servo-mounting rails. There seems to be plenty of room for all
the gear.
At the back end the tailplane
mounting is very wide with a nice radius up from the fuselage. As well as providing the
base for the V tail to sit on it will also reduce drag, which is a nice touch. The
tailplane is secured by one Allen screw up through the bottom of the fuselage and an alloy
locating pin from the front of the tailplane into the top of the tail plane mounting in
the fuselage.
The rear of the fuselage is nicely
rounded up to the tailplane to blank off the back of the fuselage and enclose the
ruddervator linkages. The two ruddervator snakes come pre-fitted.
The centre section of the fuselage
that accommodates the two-piece wing mounting is quite complex being moulded with holes
for the wing joiner, two locating dowels and plugs for the flap and aileron servo
connections. It is easier to look at the photos than for me to describe it. Of course this
area is covered when the wing is in place. It is a lovely piece of design and moulding.
A final nice touch is that two
flats have been moulded into the nose cone to match the two on the fuselage inner nose, so
that the nose cone will match up perfectly with the fuselage when in position.
Jaro always puts a lot of thought
into designing his models and this one is no exception, with great attention to detail and
beautiful moulding. The wing planform has an elliptical leading edge and a straight
trailing edge. As a competition flyer my only criticism is that this planform may be a
little conservative. The tips are quite wide and therefore no tip stalling should be
experienced. A narrower tip would have increased the aspect ratio and hence the efficiency
and roll rate. I appreciate that manufacturers have to appeal to a larger market than just
the experienced competition flyers and we therefore have to accept such compromises.
Polyhedral is used on this model,
which I personally prefer. The wing section is the Quabeck HQW 2/8. (HQW 2/8 is fast
becoming the new RG15 and with good reason, it's a great section. KN) As is normal the
model is fitted with flaps and ailerons. The ailerons are split into two sections in order
to allow free movement all the way to the wing tip despite the changing hinge-line. The
segments are mechanically connected and engineered so that even at full deflection only
the smallest of gaps is created between both segments. Some simple testing of the ailerons
revealed the torsional rigidity to be perfectly acceptable. It is possible separate the
outboard section of each aileron and operate them independently but we chose not to.
The hinging on both the wing and
tailplane is of the living hinge type. This is where the clever stuff starts. After the
wing has been moulded the ailerons and flaps have been cut out and the hinge released, the
leading edge of the ailerons and flaps have another moulding attached to form the knuckle.
Another mystery is that although
the top and bottom of the wing, including the ailerons and flaps, are moulded in one piece
in order to make the living hinge, the ends of ailerons and flaps are moulded over, when
logic says they should be ragged having been cut to release them from the main wing. This
is clearly a very clever piece of moulding.
Putting it Together
It has to be said that the Ellipse
4 goes together very easy and anyone who has assembled a moulded model before will have no
difficulty with this one. Having said that, there are no instructions with this model and
this means that a little thought has to be used on some of the detailed assembly.
Be aware that the aileron and flap
horns, which screw into the tapped holes provided, are of different lengths and if they
are not in the correct places the aileron or flap will not work correctly as the pushrods
will bind.
The wing joiner, which is a
substantial hollow carbon fibre moulding of 25 x 13 x 290 mm, had to be persuaded to fit
as it was extremely tight. A couple of minutes with some very fine wet and dry soon sorted
it out. It was the same with the wing locating dowels.
Multiplex plugs and sockets were
supplied for the wing to fuselage connections and I fixed these permanently in place so
that when the wings are fitted in place the plugs automatically engage. One small point,
in the bits and pieces bag was a small length of alloy tube about 4 mm diameter by 25 mm
long. For the life of me I couldn't reason out what it was for until I spoke to one of the
boys who flies an Escape who informed me that it was the tailplane locating pin. Mystery
solved!
As previously mentioned the
ruddervator snakes are pre-fitted. I have a reservation here in that they appear to be
made from stainless steel, which could cause problems with solder. I have soldered mine
but I am not too comfortable with the situation although I have not heard of any reported
problems.
The last job that had to be done
was making some ballast. Inspection of the Ellipse 4 indicated that whereas my normal
ballast would be a number of small slugs and spacers the Ellipse needs a one-piece item
held in place with a large knurled screw. I produced my own version using cast lead slugs
with a hole in the middle, which, together with appropriate wooden spacers, slip onto a
threaded rod with a bracket fitted to one end. All this is held together with wing nuts.
With this system it is easy to adjust the wing loading and also adjust the ballast for the
CG.
After setting the model up on the
bench with the recommended CG (99 mm from the leading edge) and the adjustable tow hook to
match, I set about balancing the wings laterally. To my surprise and credit to Jaro no
balancing was required. The elevator, flap and aileron movements were also set-up.
I am always reluctant to give
measurements for these as in my experience most competition pilots have there own ideas on
these settings, especially for the launch phase. The configurations for launch are
innumerable depending on whether you want a fast launch, where the tow hook would be well
foreword with possibly some up elevator built in, or a slower launch with the hook well
back giving high tension and could need down elevator built in.
Flying
On the flying field the normal hand
launch produced a very flat long glide. As I have said before, you cannot get the best
launch set up unless the CG is correctly set and so all the initial flights were used with
this in mind, although some adjustments to the launch settings were made as we went along.
Eventually the CG was moved back
until it was to our liking (105 mm from the leading edge). This now meant that the launch
could be sorted out for best results and unlike some models this was quite an easy
exercise and was completed on our second outing, which is unusual for us. What this boils
down to is that the Ellipse 4 is an easy model to set up.
Speed and Distance were also set up
in a relatively short time. If you have set-up a Cobra or Tragi or the like then you
should not experience any difficulty in tailoring the Ellipse 4 to your needs.
After the initial tinkering with
settings it was just a matter of flying the model as much as possible to get used to it.
Everything that was asked of the
model was performed efficiently and without fuss. The launch is straight and true
(remember to use the rudder for steering on the line as excessive use of the ailerons can
cause all sorts of nasties on tow).
The performance in the Distance
task proved to be very good, with good turns at each end of the course.
Speed was again good. Indeed I have
just seen some results from an international F3B competition in Austria where an Ellipse 4
set the fastest time of the event.
Duration performance proved to be
more than adequate. Using about 2 degrees of positive flap the model will hang around very
well and in lift will go with the best of them. This fact could make it a good model for
F3J. It is relatively light at 2.17 kg, which, together with a wing area of 65.7 dm, gives
it a good soaring ability for those days when there is a little wind about.
However when the wind picks up
ballast is required to enable the pilot to search for lift comfortably.
Add to this the very good launching
and you have a super all-round model. I am not sure if the Escape wing will fit onto this
fuselage but if it will then perhaps Escape owners would only need to buy a set of wings
and they would have two models in one! (I believe the fuselages are indeed
interchangeable. KN)
One problem that did occur (not
only to me I might add) at a recent international comp, at Kassel in Germany, was the
ballast situation. The weekend proved to be extremely windy - it was probably above the
legal limit, which is around 25 mph. It was so windy that I had almost all of the ballast
in the model for Duration. This meant of course that for Distance and Speed I was unable
to get enough ballast in the model and suffered accordingly. Full ballast weighs in at 30
ounces but since then I have made up some ballast that fits into the hollow joiner - a
trick used by the locals in Germany.
In summary, this model can be
easily set up to produce an excellent performance. It has not yet flown in the BMFA F3B
League, but hopefully that will change soon.
All in all it's a fine model that
will appeal to a large section of F3B and sports flyers. It could also do well in F3F,
although it may be a little on the large side.
Specifications
Wing span 3150 mm
Length 1440 mm
Weight 2150 g
Wing section HQ 2/8
Wing area 65.7 dm2
Elevator section sym 8%
Elevator area 6.5 dm2
Construction Fully moulded
Manufacturer's website www2.profi.sk/jaro_muller
Price UK £650 (approximately)
Price US $1150
If you want an Ellipse 4 conact:
In the UK
Soarhigh
6a The Square
Turriff
Aberdeenshire
Scotland
AB53 4AH
Tel +44 (0)1888 560446
Fax +44 (0)1888 563251
E-mail address - guy@soarhigh.co.uk
Web address - http://www.europa-gliders.co.uk
In the USA
Aero-Model Inc
2122 W. 5th Place
Tempe
AZ. 85281
Tel 480 726 7519
E-mail address - aeromodel@qwest.net
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