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tyro major multi task combat wing
This was 1 of my later attempts at aircraft design. I wanted something fast, aerobatic. I also wanted to drop things from the wings.
Limited by what was available ie. the Skyleader 3 channel 27M radio, OS25 engine.
I designed the wings around standard 3' length balsa with a 1/16" sheet D
box and balsa spars, with an otherwise open structure.
The depth of the wing was just deep enough to fit the standard servo flush, so
that the wing could knock off cleanly in impacts (usual dowel and rubber band
arrangement).
Used the 1 "white spot" servo that works in the opposite sense to normal, in
order to get the ailerons to work correctly using plastic bellcranks and piano
wire push rods.
This made the wing a bit too deep for speed really. Also, a flat bottomed
section (to make it easy to build) is not very good aerodynamically.
Recently getting into electronics, I made a simple oscillator with some high
power transistors to go in the wing, driving bulbs alternately in transparent,
silver foil lined areas at the front of each wing tip.
This was meant to improve visibilty in dusk conditions. Never actually got
used, as it would be too risky to drive these from the radio supply.
I put slots in the underside of each wing which could take a loop of wire,
retained by spring loaded pins, held in place by further loops in the centre
section.
These in turn were held in place by a pin sticking up into the wing from the
fuselage.
When triggered this would be withdrawn and release whatever the wings were
carrying.
Lacking any spare channels/servos this was to be triggered by activation of
extreme control of either elevator or throttle (I can't remember which - I
suppose I could go and have a look). Again, never actually used.
Finished in the usual red solarfilm, with an orange/yellow orientation stripe
on 1 wing.
The fuselage was just a square box big enough (just!) to carry the engine,
tank and radio.
The tailplane had a rather large elevator with a thread hinge. My idea was that
this would be half way to a fully flying tail surface.
Unfortunately it tended to be a bit floppy and vague.
I fitted a 3.5mm jack socket to the fuselage side, wired to the glow plug, so
that the glow could be applied/removed really easily.
This actually worked well, and I used the same setup on a stock car.
Engine has the (by then) standard pressure feed from the silencer to the clunk
tank.
Engine bearers are actually parallel to the bottom of the wing, but a bit of
down thrust was obtained by puuting some washers under the rear engine mounting
screws.
Didn't think of any clever way of retaining the tank hatch, so it was held down
with a rubber band.
I don't really remember much about flying this when I built it.
I'm pretty sure it did fly, as I remember the engine starting nicely.
I think the rather large amount of play in the aileron linkages, no dihedral,
and the floppy tail/elevator made trimming it impossible, so rather hard work
to fly.
When I got back into flying this was 1 of the few intact aircraft available,
so I put the new Futaba radio into it and went to fly it at Warwick.
Did all the usual pre flight checks, including waggling all the control
surfaces and launched it.
A slight drop of 1 wing required a small correction, but it got much worse, and
quickly smacked into the ground at full power, upside down.
Analysis revealed my error.
All new radio comes with channel reversing switches now, so all servos are
standard sense operation.
I had forgotten that the original radio fitted had a reversed servo in the
wing.
Now I check for correct sense of control before launch.
The front of the wing got a bit squashed back in the crash and 1 of the wing
bellcranks broke away.
I repaired this, but haven't tried to fly it since.
There are better thing to fly now, mostly gliders or electric.
I still have the airframe though.