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1/3 scale Grunau Baby IIb by Schneider - Wings

First the spars have to be built. They consist of upper and lower sparcaps ( 5x10 mm spruce), sandwiched between the shearwebs,

which are made of 3mm litepley CNC parts. All the ribs consist of forward and aft "halfribs", in the d-box, there is twice the amount

of halfribs as aft of the spar. At the root, the aluminium joiner fitting is also sandwiched between the shearwebs, also, between

ribs 14-16, the spar is reinforced, this is where the wingstrut fitting will be attached.

shearwebbing sparcaps joiner fitting

The last 2 pictures show the reinforcement where the strut fitting will be attached, and the main fitting for attachment to the fuselage,

each wing has 3 attachment points at the fuselage, plus the wing strut.

Test fitting the ribs, note that the wing runs the whole length of my building table, which is a 4x8 plywood sheet !

The fit of the parts is very good, most of the ribs fit so tightly in their slots, that I will be able to use thin CA,

which should speed things up nicely.

Here the forward half-ribs, as well as the aft ribs in the aileron area are already installed, and the aileron ribs are being fitted.

Dragspar and shear webbing installation, on the 2 r/h pics the spruce LE is installed and the aft halfribs

Here, the trailing edge is already installed, it is 3 x 15 mm spruce. The triangular gussets are not to scale, and not included in the kit.

I made the myself from triangular balsa stock, since I felt the trailing edge needed a bit more area to hang on to the ribs.

These are the fittings for the wing struts, made from 2mm thick aluminium, and bolted to the airframe. the 2 upper ones are for the fuselage,

the lower for the wing fitting. Next picture shows the wiring for the airleron and spoiler servos installed in the d-box.

Here I have begun sheeting the wing, The sheeting is 0.6 mm ( 0.025 in ) plywood, and applied with the iron-on method.

For this, white glue ( titebond) is applied to both parts, and let dry until it is dry to the touch ( approx.20 min ) Then the sheeting is

put in place, wetted on the outside and heat is applied with the covering iron. The heat will momentarily soften the partially dried

glue again, this allowing it to bond. The water is to help with the heat transfer, and to make the plywood flexible enough to be

pilled around the leading edge.

This process takes some practice ( the first field , I had to do 3 times... ) but I am now getting the hang of it.

Here the first finished wing, still need to fit the aileron :

skinning the aileron, and the left aileron, skinned and hinged, left wing is ready to cover