Prodij is a sailplane intended for high performance slope flight and racing in the 60” speed category and for use with the catapults (Zip launch). Do to the high speed it is necessary at the time construction to have no slop in the control system. Its small size makes it very handy without conceding performance. To be able to exploit all slope conditions it is necessary to be able to ballast. One should not neglect this stage of construction. The recommended radio installation takes account of this constraint and we strongly advise it to you. If nevertheless you must make a personal installation take into account the requirement for ballast. Painting is of an acrylic type that does not like solvents. It is necessary to avoid alcohol and other white spirit. Best to use is soapy water. The kit makes it possible to choose between various options of radio installation, according to your criteria:
Version 2 axes:
Ailerons - Elevator. This version makes it possible to enjoy slope flight with 2 micro-servos, and does not require a programmable radio.
Version 3 axes:
Elevator - Rudder - Ailerons. This version is more fun for stunt flying. With a stab and fin it does not require a programmable radio. If you on the other hand use a programmable radio we advise you to set up the model as a v-tail.
Version 4 axes:
Elevator - Rudder - Ailerons - Flaps. Prodij was especially conceived for the 4 axes. I.e. that its flaps (2 ailerons which bends down at the same time) are very effective. This version also makes it possible to benefit from air-brakes (2 ailerons which rises at the same time) very effective. It claims 4 micro-servos or 4 sub-micro servos and a programmable radio, but gives the greatest versatility and performance in flight. It is with this version and a mixing elevator towards flaps that one will obtain the best performances in pylon racing.
The duration of construction is 7 to 10 hours.
Technical information :
Span : 1500 mm
Surface : 20 dm2
Profil : MG 06
Length: 840 mm
Weight : 650 g to 750g
Ballast : 300 g
Loading : 32.5 à 37.5g/dm2
n *1 servo tray
n *4 Clevis links
n *4 threaded rods m2 for the commands of ailerons, and the rods of stab.
n *2 carbon tubes diameter 4mm for the pushrods.
n *2 8-32 wing screws.
n *2 8-32 blind nuts.
n *1 plywood pylon blind nut mount.
n Adhesive doubles face for the fixing of the 2,3 or 4 servos in the fuselage (Goop or 5-minute epoxy)
n 2 small screws for the servo tray to fuselage. *
n 1 Hinge tape for the ailerons
n Oracover for the stab.
n A small piece of 3oz. F/G for reinforcing the v-tail joint.
n Epoxy resin, micro balloon and the cyano.
n 1 tube silicone for the hinges.
n 1 light tube (PVC) of diameter 14mm X 250 mm for the tube with ballast
* is provided in the kit.
The ailerons are 5.1 cm (30% of the chord) at the root and 1.6 cm at the tip.
bead of Silicon to the inside of the hinge and set asside to cure. Use
masking tape to hold the control surface in position. Make sure the wing
TE has enough clearance for downward movment. Fill
control surface with a thick mixture of micro balloons and epoxy. Dig
out ¼ of foam from the face of the control surface and TE of wing.
Lay a bead of Silicon to the inside of the hinge and set asside to cure.
Use masking tape to hold the control surface in position. Make sure the wing TE has enough clearance for downward movment.
Fill control surface with a thick mixture of micro balloons and epoxy.
Dig out ¼ of foam from the face of the control surface and TE of wing.
The installation of the control horns is done classically. We recommend ball links for an easy assembly on the ground and a tight linkage. Drill a hole into the micro balloon fill and epoxy in the ball link assembly. For the ailerons make the pivot 10mm from the lower skin and in line with the hinge line..
The wing is attached to the fuselage by 2 screws 8-32. The wing is reinforced at the places planned for the screws; it is enough to bore vertically 2 holes with a diameter .201 . 20 mm and 110 mm from the leading edge. The wing is pre-marked in the mold. Then countersink the holes to receive the head of screw. Attention : I advise to do it by hand because a drilling machine is often too violent.
In the case of the option wing in 2 parts, a simple method of fixing is to file 2 half holes on each wing root on same the level as the holes of the version into 1 piece c.à.d. to 2 and 10 cm of the leading edge. For the assembly on the ground, it will then be necessary to assemble the 2 half-wings with the keys, to lock them with Scotch tape of electrician, and to screw the 2 screws Nylon provided with discs of external diameter çm.
It is necessary to sandpaper the leading edge into round and the flaps in skew to refine the trailing edge
The control elevators horns are made from piano wires of 2mm of diameter. It is necessary to cut 2 pieces of 5 cm length, it is necessary to solder a ball link ball to the end, bend the end having the ball to 2 cm with 55° (approximately!). Then fold the other extremity with right angle. Bond this end with epoxy or the cyano + balsa dust in the elevator, 3 mm behind the hinge line.
The stab can be glassed or covered with film, the second solution is lighter and more rapid the dihedral is approximately 110 °, it can be bonded with cyano + balsa dust in reinforcement. Sandpaper the lower part of the stab flat, dull fuselage then to point the stab with the cyano. Reinforce joining with epoxy, or the cyano + balsa dust by forming a fillet to the fuse.
It is necessary to epoxy and micro balloon the plywood wing plate to the inside of the pylon. Sand the inside of the pylon some to scratch the surface and remove any bumps that are in the way. Mix a small batch of epoxy and micro balloons, apply to the plate and put the plate into position until the epoxy has cured. Keep this plate flat against the top of the fuse pylon.
Then it is necessary to bore 2 holes diameter 5mm (.196) check the wing alignment by measuring equal distance from the wing tip to the fuse seam at the tail. Mark the fuselage through the clamp holes, remove the wing and drill through the top of the fuselage and plate. Open the holes to receive the OD of the nut plate and pull the nut plate into the pylon from the bottom. Use the wing screw and some larger washers to pull the nut into the plate.
The fuselage receives all the servos (2,3 or 4 according to the selected version), the receiver and an battery 4 elements of 500mAh. While placing battery at the good place (not inevitably ahead one should arrive at a correct centering without lead addition in the nose or the tail. For the servos one can even find place for 2 servos standard but with mini servos or micro servos one will be able to carry more ballast. Attach servo rails to the tray and secure the servos with screws.
Here an example with 4 microcomputer-servo for the flaps and the stab:
The servo tray is placed in the fuselage and is screwed by 2 round head wood screws directly by exterior, on the right blank of the fuselage.
With this method of assembly radio operator, the radio is easily accessible and does not weaken the fuselage at any point.
Drill 2 holes on the end of the pylon for the passage of the rods of the ailerons.
The rod of ailerons are simple threaded rods m2. The precision adjustment will be made by turning the clevis. Make sure they are a straight shot to the control horn.
The 2 rods of elevator will be made out of carbon tube of 4mm of diameter with inserts of threaded rods with each fast end stuck to epoxy. For the length, the method is the same one as for the ailerons.
To increase its flight envelope, it is well of being able to ballast the Prodij. Install a tube for ballast in the fuselage, which can receive 300g. Stick it on the left blank of the fuselage, with polyurethane adhesive. PVC Tubes of 15mm diameter (EMT) or It is necessary that the center of the tube be installed at the CG of the model.
A good solution is to take support on the locating spigot what gives a good distribution of the forces at the time of launched and that makes it possible to stop the end of the tube automatically.
Set the CG to 75 mm of the leading edge. With an battery of 4x500mAh, it almost does not require lead. For the first flights one can advance the CG of 5mm by adding 15g in the nose.
Positive (+) values refer to down movement of the control surface in question and are measured at root of the control surface.
Elevator -7 / +7mm
Rudder -8 / +8mm
Ailerons -13/ +9mm
Crow -20mm Flight
The first flight will be done without ballast, all the control surfaces exactly with the neutral, CG 70mm from the leading edge.
Move back the CG to 75mm of the leading edge according to your impressions. It will be necessary to compensate with more down trim, it is normal. Reasonable back limit being 78mm. Start to familiarize yourself with the sailplane before adding ballast.
One can ballast the Prodij to fly in strong wind. The behavior of the sailplane changes completely. Speed increases considerably. Do Not exceed 500g because the turn radius will suffer.
Add camber to maintain flight in light slope conditions. Camber is very effective on the Prodij.
For catapult-launching one needs a hook located 2-3cm before the leading edge. A simple method is to fold a wire so that it comes to be caught around the launching peg, bend a hook with the other end. This end being taped around the fuselage.
(Thanks to Tom Copp for these English Building Instructions)
COMPOSITE SPECIALTIES 949-645-7032 Costa Mesa, CA 92627