L'ALDIJ D'Aeromod

The ALDIJ is a sailplane especially designed for the flight of slope and more particularly for the competition of sailplane F3F. The use of flaps and ailerons whose cord are with nearly 30% gets for this sailplane capacities of flight which come out of the ordinary.

The F3F is a category FAI which are practiced between 2 pylons separated by 100 meters where should be made 10 bases as soon as possible whatever the weather. It is a fast sailplane if the wind is strong and fine as soon as the bearing pressure drops. If the sailplanes of F3B go well, they have a major disadvantage, it is the price (+ of 5 000 FR.).

The ALDIJ is a sailplane produced by young company AEROMOD and distributed mainly by the store the PYRENEES MODELS of Toulouse.

This company is animated by Alexis Maréchal, young aeronautical engineer, who after having practiced the board with veil, discovered the joys of model making and more particularly those of the flight of slope.

This rather recent discovery, since it has practiced for only three years, was facilitated by Marcel Gwang who is known in the medium to have created Pibros.

The experiment of the one and the technological choices of the other gave rise to a line of sailplane whose design and realization constitute a real innovation.

AEROMOD wished to build a high performance composite sailplane and whose price was reasonable. It was a question of finding an ballance between the time spent to the molding and the selling price. The method of manufacture of the fuselage remains traditional, that of the wings is very optimized and remains a secrecy jealously kept by the manufacturer.

One does not expect a box with pretty stickers and beautiful photographs. I did not have the box since I passed directly to the store what saves the carriage costs (90 FR.).

The contents of the kit are summarized with a fuselage with a nose cone, a wing in three parts, a stabilizer, 4 tubes out of carbon for the rods of wing and an explanatory leaflet (which you can obtain by Internet if you lose it).

I will not recopy the note which is sufficiently detailed to conclude the assembly of the model but to explain the stages by which I passed and the differences compared to this note.

The wing of the ALDIJ is in 3 parts: the central plan and 2 external panels. The profile used one 7003 is modified. This wing is manufactured entirely out of composite materials and the principal fabric is uni-directional carbon/glass cloth. The central panel supports the flap on all the scale and in an original way the 2 servos of ailerons at each end.

You can use 8mm carbon rods or piano wire for the heavy weather (supplement of mass of 300 G).

It is necessary to trace with the under-surface and the top surface, the site of the flap. Attention, the under-surface must be broader than the top surface (see drawing).

For cutting, I advise you to use a rule to be papered (which I cut to one meter). This metal rule is maintained on the wing with Scotch tape of packing. I used a traditional cutter but I changed the blade for each control surface. It is necessary to be patient and not to seek to cut out the skin of the first blow. At the end of some master keys, you will feel that the blade crossed the layer of fabrics. It is necessary to pass on other side and to make the same thing.

(New Aldij models have all the surfaces pre-cut. f3x)

Same operation used for the central flap except that it is necessary to initially cut out the end of the aileron by the tip with an angle to cross more to the under-surface that to the top surface.

I used cement silicone (small white or translucent tube) to make the hinges and here the procedure:

It is initially necessary to sandpaper the flap, the ailerons, the central panel and the external panels with a large hold to be sandpapered. I recommend the tools Perma Grit to you (free advertising) which are excellent on all materials. Once that the edge are right, it is necessary to sandpaper the interior side wing so that the ailerons and the flaps come to be embedded when the control surface is directed to the bottom (see drawing of the form). To obtain a good result, you can stick sandpaper on an end of plywood of 2 mm, 4 20 cm length cm broad and. Simulate the hinge with Scotch tape and check if the flap and the ailerons re-enter without forcing (sandpaper if it is necessary). Stick Scotch tape all along the control surfaces and scrape a little bit of polystyrene at the place of the hinge (on 2 mm) then you can put silicone all along the slit (cut the end of the tube to obtain a cord of 1.5 mm). once that silicone is extended, maintain the control surfaces downwards and let dry.

The following day, you can remove the Scotch tape and test clearance.

I used HS 85BB from HITEC. The wooden support is already stuck in the central panel, it is enough to make housing with the Dremel or the soldering iron.

On the central level, a hole in polystyrene is designed to pass wire of servos. It is necessary to defer the coasts indicated on the note to make the hole in the middle of the central panel. Use a piano wire and insert the whole length starting from the end until you see the wire that you catch with a small grip. Repeat the operation on other side and you pass wire of servos while pulling on the wire.

For connection with the fuselage, I used a catch 5 contacts from Multiplex by distributing the 2 signals, 2 more and by joining together the 2 masses.

To be able to assemble the external panels, it is necessary to mill a site in polystyrene for the head of the servos and to cut the skin to the under-surface to make pass the arm of servos and allow clearance (see drawing).

For the control horns, either you use ball links, or traditional caps. I tend to prefer these last and I made control horns in epoxy plates of printed circuit which I stick in the ailerons and the flap by making a bleeding to the skin of top surface (but without cutting it). If you use ball links, I advise you to buy the special ball link pliers.

Start by positioning the central plan on the fuselage to have a reference for the stab. For the fixing of the wing I stuck a plate of plywood of 5 mm under the base of the wing which I bored and tapped with the diameter of fastening screw of the wing (plastic screw of 5 mm). I prefer this solution with that of the claw nuts (lighter, not expensive and more solid).

To position the tubes of the keys of the stab in the fuselage, the method of tracing recommended in the note is very astute and allows a positioning without loop alignment effect.

The servo tray is a rectangle of plywood on which come to take seat 3 servos (3 HS225). As in the MINIJ and the MININCH, AEROMOD is distinguished by proposing an original solution for the installation from a servo servo tray which is screwed on the right side of the fuselage. The 2 servos of the v-tail are inverted and that of the central flap upright.

After having estimated the length between the pushrods of the v-tail and the servos, it will be enough to adjust the neutral with the position of the servo tray and to screw this one.

The pushrods are carried out with tube carbon of 5 Misters Attention to make the sufficiently long cranks of the v-tail not to have to bend the pushrods (it is necessary to pass under the tubes of the keys of the stab).

I stuck an end of 3 cm length plywood and 1 cm broad to the bottom of the fuselage and the balance of the CG to be able to fix a hook of winching which is positioned to 5 mm in front of the CG.

Do not make like me. I wanted to keep a fixed part with the root and it is practically impossible to have correct commands. It is to better cut out the mobile flap to the root because it will be easier to make the crank of command (the manufacturer modified the note).

Should be taken the precaution to shift the tubes which will receive the CAPE so that those can cross in the fuselage. Attention with drilling because the stab is not very thick. Taking into account the low relative thickness, I used a hinge with the Scotch tape rather than silicone.

To obtain the centering indicated by AEROMOD, I added 100 G of lead to before by using accumulators of 1000 mAh. These 100 G can be decreased by putting some 6 cm length keys instead of the 8 for the fixing of the stab.

Because it is a sailplane intended for the slope and more particularly for the F3F, it is necessary to be able to ballast the sailplane, i.e. to increase its wing load. While replacing the carbon keys by steel keys, one brings 300 G and while installing a tube in the fuselage, one can bring 300 G additional what, with 600 G of ballast, gives a wing load of 62 g/dm˛.

Polish with Wax a copper a tube 14 mm in diameter and 30 cm length. To wax this tube, if you do not have a wax for the resin, stick Scotch tape of packing and to wax with wax for pieces of furniture. With a fabric of 100g, try to make the turn of the tube without making bubble. It is initially necessary to put the resin on the tube then the fabric. When this first layer is dry, it is necessary to cut all along the tube to release it. To wax the tube again, to position the fibre sleeve and to check that the tube slides. You can now roll up several layers of fabric. Unmould, to the ray plumbing and buy a nut for cup of 14 and one end of tube of 14 interior. Thread the nut then the tube on 10 cm without fibre and type with a hammer.

(F3X sells 1/2" dia. lead rod that will work well for ballast in the Aldij. f3x)

It is necessary to stop an end and to stick the tube on the left side of the fuselage. For the ballast, I use brass ends 50 mm length of 14 mm diameter and. The last piece is bored at the same place which the tube and I pass an end of CAPE to maintain the whole in position.

The ALDIJ, once disassembled, is not a large cumbersome sailplane and is easily packed. Without occupying all the place in the car, one can leave the stab and the central flap in place on the fuselage. Once on the slope, ijust assemble the external panels, connect the pushrods of ailerons and to put a Scotch tape end. An easy way to clean the traces of scotch and the various marks of adhesives: use WD40 (always free advertising) instead of solvents of the acetone kind or gasoline.

The ALDIJ is a sailplane which is a very wide speed ranget, it is necessary to be very particular to the adjustments of the radio.

The basic programs are those used in F3B. One declares the 3 servos wings in v-tail (Ailerons, flap, air-brakes, elevator) and the 2 servos of the v-tail out of EMPENNAGE V+ (correction on the elevator when the air-brakes come out).

A switch makes it possible to regulate a position of flap which is very useful to scrape along the slope (4 mm downwards).

A switch makes it possible to change in-flight status; During the flight, when one draw on the flap stick, the central flap and the ailerons bend down what makes it possible to increase the bearing pressure and to tease of the 4 axes, that also makes it possible to reduce the rate of turn.

For the landing and in function air-brake, the ailerons are raised and the central flap drops, the sailplane slows down and the rate of fall is significant. Even for a good correction with the elevator, it will be necessary to look after the approach. On the other hand this effectiveness makes it possible to be landed almost everywhere.

I accomplished the first flights with the electric winch. After having checked with one launched hand that the control surfaces with the neutral, the sailplane stole right, I made a winching with a first position of flap with 4 Misters the sailplane assembles right and restores correctly at output of the winch. Out of stringer, i.e. flap and ailerons with zero, the sailplane flies quickly and falls clearly. While gradually bringing back the central flap and the ailerons to the bottom, the speed and the rate of fall decrease very clearly. The limiting value of the steering is reached when the sailplane becomes soft with the ailerons and only the rudder makes it possible to keep control. Passages to low height made it possible to see the effectiveness of the air-brakes and the compensation (pitch-up moment  compensation from the elevator to be tuned).

The ALDIJ was conceived for slope and is really in this element that it is at ease.

The shape of the fuselage allows one to launched strongly. If the dynamics of the slope is weak, the flaps will make it possible to seek the best zone. Re-entered flaps, the sailplane accelerates frankly and it becomes very handy on the axis of rolling. With the steel keys, this agility decrease a little but the trajectories are extremely tended and allow catches speed comparable with the sailplanes of F3B.

The weather conditions most favorable to the ALDIJ are those of a constant wind.

Charged to 60 g/dm˛ and thanks to its rigid wing, the sailplane becomes a frightening machine in the tests of pylon but also in stunt-flying. Because of its rigidity, it is possible to take significant speeds what makes it possible to carry out very full figures.

The inclined landing does not pose a particular problem, the plastic screws act as fuse and it is necessary to envisage replacements (I consumed some at the beginning of them).

The ALDIJ is an exceptional sailplane at the aerodynamic level. Its qualities of flight make of it a very pleasant machine which asks for a training of departure and which, thereafter, gets remarkable feelings of flights.

It is necessary to pay homage to this young French company which puts on the market of the original sailplanes.

Plus:

The ALDIJ is a good sailplane in the field of the quality/price/performance/ratio.

Qualities of flight are excellent.

AEROMOD chose solutions aerodynamic and technical original and their choice was dictated by preoccupations with an effectiveness.

Less:

Defects of completion of the leading edge.

Envergure : 2200 mm

Longueur 1180 mm

Cordes : 180, 140, 90mm

Surface : 36 dm²

Profil : Selig 7003 modifié

longueur : 1150 mm

Poids à vide : 1650 g

Ballast : 250, 550g

Charge alaire : 45, 52, 61g/dm²

5 servos

ailerons HS85BB

Empennage and flap HS225

Elevator +10 mm /-10 mm

Compensation to prick air-brake 3 mm to be pricked

Derives +15 mm / -15 mm

ailerons flap central

Ailerons : +14 mm / -28 mm 0 mm

flaps lasted +4 mm 4 mm

dynamic flaps +10 mm / -6 mm +10 mm / -6 mm

elevator towards flaps +8 mm / -5 mm +8 mm / -5 mm

Air-brake -25 mm +18 mm

The sign + indicates a displacement to the bottom and signs it - a displacement upwards.

85 mm starting from the leading edge.

2400 F version glass carbon (pyjamas)

$399.00 USD carbon version

Pyrénées Modèles

USA - Composite Specialties www.f3x.com 949-645-7032

Copyright © 1998 R/C Soaring Magazine - Philippe Bataillé.
No commercial use or publication (e.g. on other www or ftp sites, print media) without a written consent.