(4) M4 Split-Ring Lock Washers
(4) M4 Blind Nuts
(1) Hook-and-Loop Tape (Velcro
®
)
(1) Set Electric Motor, ESC, Prop, Lipo Battery (not furnished)
NOTE:
The mounting of the electric motor in the Sbach XA-41
assumes that your motor has a typical "X" or "cross" mounting
plate on the back of the motor.
❑
24) 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 it.
❑
25) Assemble your motor according to the manufacturer's
instructions. 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.
❑
26) For the Sbach XA-41, we need a finished distance from
the back edge of the motor mount to the motor’s thrust wash-
er to end up exactly 5-1/2". This is important so the cowling
will fit properly.
a) So what you need to do is to subtract the measurement
taken in the previous step (27) from 5-1/2". The result is the
distance 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 2-1/2". So 5-
1/2" minus 2-1/2" = 3". Your result may be different.)
b) Next, carefully measure and mark the distance deter-
mined in the previous step from the back edge of the motor
mount box towards the front. Do this along side each of the
adjustment slots on both sides of the box (four marks total).
c) After you have all four slots 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 5-1/2". When satisfied it is
correct, glue the firewall securely to the rest of the motor
mount box.
❑
27) Install your motor on the firewall using the hardware
included with your motor.
a) Using four blindnuts and bolts loosely attach the motor
into the four angled slots in the firewall.
b) Check to make sure the motor is centered on the fire-
wall.
c) Put a drop of medium CA on the flanges of the blind
nuts to secure them to the plywood, but be careful not to get
any glue on the threads.
d) Tighten down all the bolts to hold the motor in place on
the firewall.
❑
28) Locate the piece of balsa triangle stock provided.
Measure, cut and install pieces to reinforce the all corner joints
inside the motor mount box. Use Med or Thick CA glue for this
job to ensure a good bond and gap filling.
❑
29) Install your Speed Controller (ESC).
a) Solder appropriate connectors (not supplied) to the bat-
tery leads of your ESC.
b) Mount your ESC onto the side of the motor box right
behind the firewall, using one of the plastic cinch straps pro-
vided. Or if you prefer you can mount the ESC with double-
sided servo tape or Velcro
®
(neither of these are provided).
10
