RC Factory/Icare RC Crack Yak Lite
The small MP Jet brushless outrunner was a great match to the airframe. My ply
disc has four pieces of thin CF glued into the foam front end “cross section” for
added support. A couple of different props were tried with fairly similar results.
The printing on the model is quite crisp and clean. A small slit cutout for the battery
allows for some CG changes if wanted.
The spirit of the Lite Series Crack Yak 55 is an indoor/outdoor 3D aerobatic
airplane that will withstand the abuses of tight spaces, inadvertent
“touchdowns” and the learning curve of extreme flight maneuvers. Lighter is
better with this style of model and here is the best way to enjoy light flights:
Component choice is everything. When it comes to power, follow recommendations on the lower
end. The Crack Yak will accept a 2203 or 2204 motor; use the 2203 and get a higher Kv if you have
the need for speed. Make sure to also use a lightweight speed control and servos. Every gram really
does add up on a model this size.
Glue choice is up to you, but I’ve had great results with contact adhesive such as Welder’s, which
evaporates and loses weight while it dries! It has another advantage: it is not as brittle as CA. Either
way, be sparing with your glue and only use enough to get the job done; more glue is more weight.
Extreme measures can be executed if you are a weight-saving fiend like me. I have been known
to remove the four screws holding a servo case together, remove the bottom of said case, shorten
servo wires (even the internal ones!), shorten motor/speed control wires, remove battery balance
leads, remove receiver cases, remove shrink wrap from speed controls, and even leave off landing
gear (which is against my model airplane religion). I have to add that such modifications may void
warranties, so check with your manufacturer/distributor to be sure.
The “Lite Series” of Crack Yak airplanes are the
result of a proven design on a diet, shedding 1.5
ounces. The Crack Yak’s airframe parts are all
pre-printed. It used to be that EPP planes (while
being highly durable) were a little too flexible
and their precision flight capabilities suffered
in comparison to Depron planes. The Crack Yak
Lite is uniquely rigid and, once built, offers an
unusual crispness for an EPP model. A pair of
pre-beveled EPP foam trusses adds even more
stiffening with minimal weight gain and further
lowers the wing loading. Four-ply ribs hold the
twin carbon-fiber wing spars in place and once
glued in, the assembly stiffens the wing well.
Your components are all located centrally and this aids lateral balance. Remember to use your lightest gear!
The aileron hinges and the empennage
hinges are molded into the wing and tail
feathers. You will want to fold all of the control
surfaces over and allow them to sit overnight
under a book or other flat weight. This will
help loosen up the hinges and make them
easier to move thus giving a bit of relief to
your actuators. When it comes time to install
the servos, the pre-cut openings may have to
be modified to fit your particular servos. This
is quick and easy with a sharp hobby knife. I
made a slit in one of the foam trusses and was
able to conceal most of my wiring inside, which
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