The RCGF 20RE engine and muffler are installed and fit nicely in the MXS-R’s cowling.
The SFGs look great and improve the aircraft’s knife-edge capabilities.
both bolt in place with socket-head
cap screws. I elected to install the
axles, wheels, and wheel pants at the
conclusion of the build to help keep the
airplane from rolling on the workbench
The manual recommends securing
the horizontal stabilizer with thin
CA adhesive. I used 30-minute epoxy
instead, to allow more curing time to
ensure that the stabilizer was centered
and square to the fuselage. When the
epoxy was fully cured, the elevator
halves were secured in place.
The rudder installation was next. The
pull-pull cables come preinstalled in the
fuselage. After the cables are attached to
the rudder servo, the rudder installation
Next was installing the engine and
muffler. The manual only shows an
electric motor installation. The kit
recommends a 20cc to 25cc gasoline
engine. I ordered a RCGF 20 RE (rear
exhaust) engine from Taildragger RC.
The engine mounts and mounting
hardware that were included with the
engine were used to mount the engine
in place on the firewall.
The engine motor mounts were
centered on the premarked lines on the
firewall. The throttle servo was mounted
inside the fuselage and connected to the
carburetor with the included pushrod
and ball links. A simple choke linkage
was fashioned out of a servo arm and
two pieces of 4-40 pushrod material.
The ignition unit was mounted inside
the motor box, because if mounted
on the outside of the motor box, it
would rub against the cowling. A Tech-Aero Designs Ultra Ignition Battery
Eliminator Circuit (IBEC) was used to
power the ignition unit. The lightweight
IBEC unit also serves as an electronic kill
switch. It features an LED that indicates
that the ignition unit is powered up.
The airplane came with a preinstalled
fuel tank, but only 10 inches of gasoline
fuel line was included. I purchased
additional fuel line and a fuel dot at a
local hobby shop.
A 2,300 mAh 2S A123
Nanophosphate battery from Wrong
Way RC.com powers the ignition unit
and radio equipment. The receiver
switch, IBEC LED, and fuel dot were all
mounted on the outside of the fuselage.
A rotary tool with a sanding drum was
used to open the bottom of the cowling
for cylinder head clearance and cooling.
The cowling fit nicely over the engine
and the rear-mounted muffler. A Master
Airscrew 16 x 8 wood propeller and a
3-inch Hangar 9 P- 51 aluminum spinner
completed the powerplant installation.
Aerobeez has suggested control
surface throws listed on its website. The
website indicates an initial setting of 50°
throw for each of the control surfaces.
A word of caution here: This is the total
amount of deflection (both directions
I elected to start with 20° of deflection
(each direction) on all of the control
surfaces with 35% exponential. No
exponential settings were given in the
Remember, Futaba transmitters use
a negative exponential number; most
other transmitter brands use a positive
number. The control surface and
exponential settings that I used worked
great for the initial test flights and
eventually for the low-rate settings.
The airplane balanced on the
recommended center of gravity, which
80 Model Aviation JULY 2017 www.ModelAviation.com