This Fact Sheet is primarily aimed at the newcomer to Building R/C Model Aircraft.

This fact sheet applies to Wings manufactured at Probuild. Which have a Gator spar system. However, the general principles remain the same no mater what aircraft you are building that utilise a plug in wing.

Wing Installation

1. Blank off the ends of the Gator phenolic wing tube with 1/6 ply or similar. Insert into the holes that are pre bored in the wing cores and cut back allowing enough waste for the root ribs to slip over when fitted. You should make sure you now have a "CENTRE SECTION" of tube, which is LONG ENOUGH that can be fitted across the width of the fuz.
2. Mix some 101 Epoxy and smear on the tubes and insert into the wing cores, insert the wing spar and leave on a flat surface to cure.
3. The holes for the phenolic wing tube, adjusters, and wing fixing bolts, servo wires and retract push rods are pre marked on the fuz. To check the centre lines of these holes, set the fuz up level on a flat surface, ensuring that the fin is at 90deg's and the tail plane is at 0 deg's incidence to the flat surface. The wing incidence should be +1/2deg (depending on the type of model you are building). Measure up from the flat surface to the centreline of the wing on one side of the fuz, and then transfer this measurement to the opposite side of the fuz. This ensures that where the wing tube will protrude through the fuz they are of equal height and incidence, if not then transfer the higher side through to the lower side.
4. With the centre lines and holes marked out on the fuz, cut out the holes for the phenolic wing tube and the adjusters on the fuz.

The more accurate you can be in marking off the centre lines of the wing on both sides of the fuz in relation to the tail plane, the less adjustments you will need to make to get the wing to line up with the tail.

5. With the fuz held firmly upside-down in a cradle insert the centre section of the phenolic wing tube with the reinforcing plates positioned on the inside of the fuz and assemble the wings in to the wing spar in the fuz. (It is a good idea to use spacers between the fuz and the wing root to allow visibility of the Phenolic tube in the fuz.)
6. Line up the wing incidence to the correct angle and hold in position with nails pushed through the adjuster holes into the foam wing root.

7. Using your Mk 1 eyeball, and measure sight through from the rear of the fuz to the tail and wing to ensure correct alignment (both the wing and the tail must be parallel and the wing tips at the aileron hinge line should be of equal distance from the centre line of the fuz at the fin). (see Sketch)

8. To bring the wing into alignment with the tail, on the higher side of the wing, carefully sand out a VERY VERY SMALL amount at a time on the bottom of the holes where the phenolic wing tube enters the fuz.
9. When you are happy that the wing is sitting correctly aligned with the tail and fuz, dis-assemble the wing assembly. Using 101 epoxy mix with some micro fibres to a fairly stiff consistency and glue the phenolic wing tube, reinforcing plates in place. Re-assemble the wings checking incidence and alignment with tail and fuz before glue goes off.

Leave your self plenty of time for this operation, as mistakes cannot be easily rectified at this stage!

10. When the glue has cured, dis-assemble and sand the phenolic tube flush with the fuz.

Wing Root Ribs

1. Re-assemble the wings and measure and cut out the thickness required for a balsa fillet to make-up the taper between the fuz and the leading edge to the trailing edge at the root of both wings and glue in position.
2. Cut out two balsa wing root ribs and mark out the holes for the wing tube, wing fixing bolts, wing adjusters and holes for servo wires/retract push rods. Alternatively these can be made from 3mm light ply.
3. Re-enforce the area for the wing fixing bolt blind nuts with 3mm lite ply and install plastic toilet seat bolts or Alternatively you can use 5mm blind nuts with nylon studs.

4. Glue the wing ribs in position and when set sand flush with the profile of the wing.
5. If using a balsa wing root rib the wing root face should be reinforced using carbon cloth when the retracts have been fitted.
6. To tie the wing root ribs in to the balsa veneer the area around the wing root is epoxy glass skinned with 80g cloth out in a triangle from 50mm to 100mm.
7. The holes where the wing bolts protrude into the fuz will need to be re-enforced with 1/32" ply or carbon/glass nomex.

Wing Adjusters

1. Mount the wing adjuster on a lite ply plate and glue in to the Fuz. Make sure that the bolts are flush with the side of the fuz and they don't protrude to catch the wing root ribs.
2. The wing adjuster tube guide is installed in the wing root ribs and glued in position with the wings attached on the fuz, this method insures that the adjuster pegs locate in the tube guides without stressing the wing or adjuster.

Manufacturing facility

Here at Probuild we can manufacture on the premises any wing / tail section to your specifications A great deal of time and preparation is spent on producing wing cores. The cores are cut on a CNC foam cutter, which has been set up by lasers for greater accuracy. The skins are applied with epoxy resin using a vacuum bag process to provide an even pressure of around 2000lbs on each panel during the curing procedure. This helps tremendously with the bonding of the skins and makes for a stronger and lighter, wing, tail and rudder panel. The whole of the curing process is carried out on an engineer's surface table, which is totally flat and weighs around 3/4 ton. After trimming the wing panels they are then checked with a vertical vernier gauge to confirm accuracy before shipping to you the customer.

An additional bonus to this system allows all of the aileron and elevators to be faced and Kevlar hinged prior to the skins being attached to the core. A reduction in building time is a trade off to you the builder as well as having a more accurate wing or tail panel. The control surfaces are made integrally when the panel is made, therefore accuracy is also increased. Why do the other companies use a press? Simply time & money. It takes many hours longer to vac a wing & it is more expensive in consumables, but the end result is a much stronger lighter wing, Christophe also uses his own built lighter wing rather than a factory unit.