The manual calls for mini digital servos, which are unusual for
an airplane this large; however, the Tactic TSX25 servos used
were perfect for the job with more than 84 ounce-inch of torque.
The large canopy doubles as a hatch. This opens up a large portion of the fuselage, giving
access to the radio and power system equipment. It’s held in place with a single spring
Another design update that Tower Hobbies has
implemented into this Kaos is removable tail surfaces. The
vertical fin has two long threaded rods built in. These rods
fit through matching holes in the horizontal stabilizer then
through the fuselage.
Locknuts are threaded onto each of the rods using an
included plastic socket wrench, fastening the tail assembly to
the fuselage. I found it easy and with the locking tabs and pins,
everything is firmly locked in place.
Mounting the nose gear goes quickly because all of the holes
and blind nuts are preinstalled. However, this particular nose
gear assembly came with a stripped-out screw that holds on
the steering arm. I chose to drill out the hole slightly, and re-tap it for a larger screw and that solved the problem. With that
fixed, the nose gear was reattached, the steering arm installed,
and I was moving on to the powerplant.
Tower Hobbies asked that I review the Kaos with both
electric and glow power, supplying the appropriate power
systems for each. Knowing this up front, I decided to tackle
the electric version first because of the cutting needed to fit
the glow engine into the cowl.
For electric power, the first thing to do is assemble the motor’s
mounting box. It’s assembled from several pieces of laser-cut
light plywood. Because many of the pieces have offset holes,
care must be taken to ensure that things are correctly positioned
before laminating them, or gluing them in place. Small
hardwood triangle stock is included to reinforce the joints.
After it is assembled, the motor box is attached to the firewall
by four bolts that thread into the preinstalled blind nuts. The
motor—a RimFire . 80 in this case—is bolted to the front of the
box. Whatever ESC you use will likely have to be mounted to
the bottom of the motor box. I tried everything I could think of
to fit the supplied Castle Creations Phoenix 75 ESC inside the
box, but in the end, I mounted it much as shown in the manual.
Fitting the cowl requires the usual trial and error to fit it
around the nose gear and to clear the ESC. A few holes need
to be cut to allow air to cool the motor, ESC, and batteries.
Use your own judgment on their placement, and the manual
also offers some ideas. Because I needed to use this cowl
again for the glow installation, I chose to cut three large holes
in the same spot I would have to trim away for the two-stroke engine. It is slightly unconventional, but it worked well
for this review.
Now it’s time to install the radio gear. First up is installing
the rudder and elevator servos, their pushrods, and the
control horns on the tail surfaces. With the plastic guide
tubes preinstalled in the fuselage, this was easy and only took
a few minutes.
Two laser-cut light plywood shelves are included in the kit.
One is for the receiver and flight-pack battery that mounts
above the servos, toward the rear of the cabin area. The
other is for the tank/battery tray and that mounts up against
the firewall. Both trays are held in place by first gluing in
hardwood blocks, then securing the trays into position with
four screws each.
As per the instructions, I mounted the
Tactic receiver and a flight pack battery
on the rear tray. Many might argue why
I choose to use a separate flight pack
battery when the Phoenix 75 has a
built-in ESC. I’ve always used a receiver
battery for 4S or larger aircraft, just for
safety’s sake. In the case of this review,
I would need that battery for the glow
conversion, so it was a no-brainer.
With everything in place except the
battery, it was time to figure out the
center of gravity (CG). Two FlightPower
6S LiPo batteries were included: a 3,800
mAh and a 4,400 mAh. The 4,400 mAh
battery weighs the most, so I used it to
balance the Kaos.
The Kaos has a wide CG range—
between 4 and 5 inches as measured
from the wing’s leading edge at the root.
This, coupled with the long battery tray,
allowed me to position the battery for
66 Model Aviation JANUARY 2016 www.ModelAviation.com