Krick 1/4 scale Grunau Baby IIb
Part 3 - Wings
The wings also are conventional in their construction, with exception of the wing joiner system, which consists of 2 rather thin steel blades. Most of the
flight loads wil be carried by the functional wing struts.
The wing is built up side down, on a simple jig which has to be fabricated from balsa stock. On the inboard, constant chord section of the wing, it is just
a straight balsa strip supporting the rear of the ribs, and on the outboard section it is tapered :
Spar caps are 3x8 mm spruce, doubled to approx. 2/3 span.
Shearwebs : In the first 5 bays, the shearwebs are ply, from there on 2 mm balsa, vertical grain. To approximately mid-span, they are installed front & aft of the
spar, from there on outboard only on the front side.
Aileron sub-spars, aileron cross bracing, fitting for wing strut :
lower spar cap and
lower sheeting
Before sheeting the upper surface, the wiring harness and wing joiner tubes have to be installed :
Next was the aileron servo installation, here again I deviated from the plans. The plans have the aileron servo located inboard of the spoilers, driving the ailerons through bowden type push-pull cables. I opted for installing the servo clos to the aileron, for this I fabricated the servo bay, and the servo mount/cover,
servo is a Hitec HS-125 MG, which fits easily in the available space :
to
the
Spoiler & spoiler servo
installation :
The spoilers are modified Flair spoilers, like they come in Flair's Ka8 kit.
They are modified in the sense that on the Grunau Baby, they only extend
out of the upper wing surface. The spoiler servo is a Hitec HS-81MG, installed
in the wing fwd of the spar, accessible through a hatch in the lower sheeting.
It actuates the spoiler through a short bowden type push-pull cable.
Here the finished wing, before covering, and after covering and applying the same treatment as on the fuselage :
Teh covering material is Koverall by SIG, attached with nitrate dope.
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