Introduction
RTGmodel is
a Slovak-based manufacturer that has been producing F3F gliders for many years
now, and is synonymous with top notch molding quality and attention to details.
Long based on HN profiles, this new glider, the Orden, marks a breakthrough in
aerodynamic design to bring it into line with current standards (new dedicated
wing profile, thin fuselage, rounded tip, ailerons running all the way out to
the wingtip), while marking its difference by making some original choices. I
propose with this review to see if the Orden achieves its objective of
competing with the best sellers of the moment.
Kit Overview
The kit
parts. It is missing part of the ballast on the picture.
With a
wingspan of 2.88m, the Orden is rather small compared to the current trend of
2.95 to 3 meters. The choice of a small 230 mm root wing cord and tail cord is
giving it a visual aspect ratio so that the glider looks bigger. The first wing
panel is almost rectangular so that the wing area is comparable with other
gliders on the market. The tips are rounded without being elliptical, and the
ailerons run all the way out to the wingtip to maximize roll rate. The wing has
a ballast compartment that can accommodate 1.6kg of brass ballast. The wing
joiner can host 600gr of additional ballast for a total of 2.2kg. As with the
previous RTGmodel gliders, the Orden has its proprietary LDS system, which has
the particularity of having the removable control surface axis using a tool
supplied with the kit. It is a brass rod with the inside of the threaded tube
at one of its ends. Axes also have a thread. The tool is screwed onto the axis
and simply pulled. On the servo side, a wooden servo frame receives an epoxy cage
for a ball bearing that takes up the forces of the servo output gear. Do not
forget to indicate the servos’ brand you want to use when ordering.
The servo
tray is molded and drilled perfectly, with Kevlar reinforcement toward the nose
Removable
LDS axis on the control surface side
Let’s move
on to the fuselage: the diameter is reduced to a minimum on the front part to
reduce drag, like the Stribog+. On the other hand, there is no more wing root
and the nose is slightly more plunging. As in all RTGmodel productions, the
servo tray is molded and drilled, with Kevlar reinforcements: Thus, 2 large
Kevlar strips run far enough towards the nose for more strength. This fuselage
is closed by a small canopy that offers sufficient opening to access and
extract all the radio elements without any problems.
Elevator is
using standard metal clevises, easy to remove with a screw driver
Tails are a
strong innovation of the Orden: Rather small in size, they are made full with a
core in Rohacell and ‘spreadtow’ carbon fabric, but above all, they are
articulated by the middle, i. e. the hinge is inserted between the two half
cores, which avoids this hinge to work with time. It is no longer necessary to
make sealing wipers, as the gap is reduced to a minimum. Another positive point
of these tail planes, they are very light at only 30/31gr including the carbon
rod joiner, but still robust. On these tail planes are the usual aluminum horns
facing upwards, which receive the 2mm metal clevises (no ball joint clevis). In
use, it is very practical to mount / remove tails when travelling.
The Orden in the snow during 2020 spring
RTGmodel’ s
trademark remains the quality of molding and finishing down to the last detail,
and the Orden is no exception to the rule, all adjustments are perfect, the
surfaces and paint offer a superb shine, deep colors, in short, a very
beautiful work. Finally, here are the weights of the various components:
- Left
tail: 31gr
- Right
tail: 30gr
- Left
wing: 602gr
- Right
wing: 608gr
- Fuselage:
275gr
- Wing
joiner: 95gr
- Total:
1640gr before assembly
Straight Forward Assembly
In the more
than 25 years I have been doing F3F in competition, I have had the opportunity
to fly a large number of gliders. Some require a little more work and
attention. This is not the case with the Orden, which has no surprises or
particular difficulties. At first glance, I thought that the radio installation
in the fuselage would be complicated because of its narrowness, but this is not
the case. I even found the assembly more ‘spacey’ than on the Stribog+. The
molded servo plate is perfectly positioned in height and the slight offset in
opposition of each servo makes them ideally positioned and the control rods
perfectly aligned. The servos are inserted without forcing on the plate,
without risk of damaging the output of the servo wire. A little trick on the
way to screw the servos in place: I place the servos at the stop of their
housing and insert a small custom-made part between the two servos, with two
screws. This assembly ensures that the servos are perfectly held without any
lack of material for the screws.
Fuselage is
tight but finally components find their place easily
Personally,
I mount the female green plugs on the fuselage and the male plugs in the wings.
Plug recesses on the fuselage root are perfectly adjusted. Once the wiring is
done, I make two small parts in 1mm plywood to serve as a stop to the green
plug (with a 2mm shrinkage on the edges), and improve the bonding. First of
all, I glue these two pieces with fast epoxy, then I install and glue the green
plugs, always with fast epoxy. To ensure that the grips are positioned
perpendicular to the root, I have made 3D printing templates in which I block
the green grips during gluing, which also allows me to use clamps during
drying.
For the
wings, the work consists in gluing the wooden servo frames in place, wiring and
then assembling the servos. However, I always add a step which is to put an
additional piece of carbon fabric to stiffen the skin even more so that the
glued frame and its servos do not deform the top surface. A small sanding
before gluing the frames allows a better grip.
The LDS
system is unique to RTGmodel and includes a wooden frame, an epoxy cage
receiving the external bearing, an epoxy arm, and an aluminum servo head with
its axis and clamping screws. The arms for the flaps are a few millimetres
longer, so I advise you to identify them first.
Ailerons
LDS mounted on a MKS HBL6625mini. No slop at all, even after a season.
Start by
gluing the bearing cage to its wooden frame, and then insert the ball bearing
into it. The frame must be glued in the correct position, so it is necessary to
start by installing the epoxy arm on the steering side and then connect the
roll drive to the arm. This then makes it possible to glue the frames,
perfectly positioned, with the roll drive in its housing, and optionally the
servos, protected from the glue by a plastic film or thin tape. Do not forget
when gluing to put a small piece of 3mm by 3mm paper tape on each frame screw
hole so that the glue does not get in.
The green
plug is glued to the root rib with the wing in place on the fuselage, all
surfaces being protected with fine tape and release agent (polyvinyl alcohol
solution).
A picture
is often better than a long speech, so you can find all the pictures of the
glider assembly here in my RTGmodel Order Assembly Log.
Small check
on the scale, 2175gr empty in flying order, it’s very good and let oversee a
versatile glider!
Let’s go to the slope!
I finished
assembling the Orden just before leaving for the FAI competition at Col de
Tende mid-July 2019. So I stopped on my way, near Gap, to make the maiden
flight. Lift conditions were rather light that day, but the Orden perfectly
performed its flight, I just moved back the CG a little to help retain energy
in turns.
Forty-eight
hours later, following a crash where I damaged my primary glider, I switched to
the Orden and finished the competition with it, winning three out of seven
rounds with the Orden, and winning the competition, so very satisfied with such
an introduction!
Onboard
picture with a camera attached to the wing tip
What about
the glider: in F3F, we don’t only look for straight line speed, but a clever
mix between speed and energy retention in turns. The Orden has precisely these
two qualities. Able to accelerate and fly fast in a straight line, its turning
behaviour is excellent, combining stability and acceleration when exiting the
turn, provided that the snap-flaps are well adjusted. Under certain conditions
you can even feel a kind of ‘kick in the ass’ acceleration of the glider.
According to the manufacturer, the CG range is between 90 and 100mm. I’m
personally started at 95mm and finished at 98.5mm.
In light
conditions, the low weight of the glider at 2175grs is an advantage. You can
then stick to the slope and tighten the turn without any problems. As soon as
the lift is becoming stronger, the turn is widened to an ‘energy management’
style turn, i.e. the glider describes a turn away from the ridge with a 45°
slope to get grip while on the edge, then return to the ridge and ‘screw’ in
front of the pilot to start preparing for the second turn. This turning
technique requires heavier flying.
In very
strong wind and while flying ballasted around 4kg, I noticed a slight bending
of the wings in high G turns, without any consequences. For information, my
version is a ‘standard’ version, double carbon, i. e. a sandwich composed of a
90gr/m2 outer fabric / Airex / 60gr/m2 spread tow inner fabric. A strong double
carbon version is always available with a sandwich composed of a 160gr/m2 outer
fabric / Airex / 80gr/m2 inner fabric.
Since then,
I have also tested this strong layup wings and could check the excellent
stiffness for an empty flying weight around 2350gr only which remains an
excellent compromise to cover most of the conditions.
Pictures of
the Orden in flight. The plane is providing a high level of performance, both
for sport flying but for F3F competition too
The Orden
accommodates many different flying and turning styles. It is just the amount of
elevator that allows you to switch from one style of turn to another; there is
no need to change the snap-flaps ratio.
The Orden
in good company with the Penguin F3F from Jean Luc Foucher a home designed,
milled and molded F3F plane with radical choices
In typical
sport flying, the qualities mentioned above make the Orden an excellent
companion that adapts to all conditions: Light weather and thermal ‘hunting’,
more dynamic wind or aerobatics, very strong wind and ballistic flight.
Circling holds perfectly, helped by the small dihedral of the wing. Transitions
to travel from thermal to thermal are a simple exercice and allow you to
explore the airspace quickly without losing altitude, and the flaps in the
thermal position are effective.
All the
basic aerobatics goes smoothly even if it is not the glider’s vocation.
Quadroflaps bring vivacity and precision. On landing, the ‘butterfly’ mix works
perfectly and allows you to land short.
In short,
the versatility is there and the Orden will give a lot of satisfaction to its
pilot whatever the flying conditions or the flying style!
The author
with his Orden few minutes before the maiden flight
The final word
RTGmodel
has succeeded in his bet because the Orden offers much more than just an
evolution of the Stribog and Stribog+ but is now able to compete with the
market best-sellers. It therefore offers a beautiful alternative for those who
want to fly different, with an extremely well built glider, and dreadfully
effective in all circumstances. To fly without moderation, whether for sport
flying or F3F competition. Have a good flight, everyone!
RTGmodel’s
Orden plan view. (image: RTGmodel)
Characteristics
- Wingspan:
2885 mm
- Length:
1470 mm
- Wing area: 54.74 dm2 (FAI : 60 dm2)
- Empty weight: 2175gr (max FAI : 4500gr)
- Manufacturer: RTGmodel
- Contact:
Milan Demcisak, Polna 3174/6, 01001 Zilina, Slovakia
Settings
- CG:
98.5mm
- Elevator :
6mm up/down
- Rudder:
8mm up/down
- Function ailerons: Ailerons : 28 up / 14 down,
Flap: 15 up / 8 down
- Function snap-flaps: Flaps: 7mm down at full
elevator, Ailerons: trailing edge aligned
- Function butterfly: Flaps: 45mm down, Ailerons:
23mm up, Elevator compensation: 5mm down
- Thermal position: Flaps: 4mm down, Ailerons
trailing edge aligned
- Speed position: Flaps: 1mm up, Ailerons
trailing edge aligned
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