❑
25) Locate the pre-cut pushrod exit hole for the rudder on the
left side of the fuselage at the back of the plane and repeat step
24) in its entirety to install the rudder pushrod.
Skip this section if your using a glow engine power setup
ELECTRIC MOTOR & ESC INSTALLATION
For this section you will need:
(1) Fuselage
(1) Plywood Electric Motor Mount
(1) Balsa Triangle Stock
(4) M4 x 20mm Socket-Head Bolts
(4) M4 Split-Ring Lock Washers
(4) M4 Flat Metal Washers
(4) M4 x 16mm Socket-Head Bolts
(4) M4 Split-Ring Lock Washers
(4) M4 Blind Nuts
(2) Plywood Battery Tray
(1) M3 x 12mm Socket-Head Bolt for battery tray
(1) M3 Flat Washer for battery tray
(1) Velcro® Strap
(1) set Electric Motor, ESC, Prop, Lipo Battery (not furnished)
NOTE: The mounting of the electric motor in the Somethin’ Xtra
assumes that your motor has a typical "X" or "cross" mounting
plate on the back of the motor. Also note that the firewall portion
of the laser-cut plywood motor mount is adjustable fore and aft to
accommodate different length motors. Next we will determine
where you should set the firewall for your particular motor.
❑
26) Assemble your motor according to the manufacturer's in-
structions. Then carefully measure the distance from the back of
the mounting plate to the front of the thrust washer*.
*
The “thrust washer” is the part of the prop adaptor where the
back of the propeller will be located.
❑
27) For the Somethin’ Xtra, you need a distance from the back
edge of the motor mount to the motor’s thrust washer to end up
exactly 4-1/4”, in order for the cowling will fit properly.
a) So what you need to do is to subtract the measurement
taken in the previous step (26) from 4.25”. The result is the dis-
tance you need to set the front of the firewall from the back edge
of the plywood motor mount box.
(With the motor we are using in
these photos, the motor measurement is 2.77”. So
4.25”
minus
2.77” = 1.48”. Your result may be different depending on your
motor.)
b) Carefully measure and mark the distance determined in the
previous step from the back side of the motor mount box towards
the front. Do this along side each of the adjustment slots on both
sides of the box.
c) After you have the box marked, carefully align the front face
of the firewall to line up with the marks. Make sure you end up
with the firewall straight and square in the box. If it is not, recheck
your marks and adjust as necessary.
d) Tack glue the firewall in place. Recheck once more to make
sure that the front of the firewall is at the correct distance from the
back of the motor mount box. That distance plus the length of
your motor must equal 4-1/4”. When satisfied it is correct, glue
the firewall securely to the rest of the motor mount box.
❑
28) Remove the X mount plate from the back of your motor and
center it on the firewall. Once you are sure it is properly located,
mark the mounting holes with a pencil. Remove the X mount and
drill out the mounting holes with a 7/32" dia. drill. Install four M4
Blind Nuts in the holes, on the back side of the firewall. Put a cou-
ple drops of glue on the flanges of the blind nuts to secure them
to the plywood. Be careful not to get any of the glue in the
threads.
❑
29) Locate the balsa triangle stock provided. Measure, cut and
glue in pieces of the triangle stock to reinforce as many of the cor-
ner joints of the motor mount box as possible, as shown in the fol-
lowing 2 photos (see arrows). Then set the mount aside to dry.
10
ELECTRIC POWER SYSTEM