17
then through the corresponding hole in the firewall. Engage the
threads of the blind nut being held in place and begin threading it
in place.
Keep pulling back on the bolt, holding the blind nut
against the firewall, while threading it fully in place. Use an Allen
wrench to continue tightening the bolt, pulling the blind nut fully into
the backside of the firewall.
Remove the bolt and repeat this
process to install the remaining blind nuts.
❑
6) Temporarily mount the engine to the two motor mount
arms, using your own hardware (again, we suggest socket head
hardened steel bolts with washers and lock nuts, as shown).
Because the engine will have to be removed in the following steps,
don't tighten the bolts yet - just enough to get the engine sitting
firmly in place on the motor mount arms.
Apply a little threadlock compound to each of the 8-32 x 25 mm
mounting bolts. Slip a split ring washer and a flat washer onto
each mounting bolt. Hold the engine/motor mount assembly in
place to the firewall and install each bolt in place to hold the
assembly to the firewall. Allow enough play in the bolts to be able
to slide the motor mount arms left or right, as needed, to center the
motor mount bases to the firewall. When everything looks about
right, firmly tighten the bolts.
❑
7) The throttle servo is now installed into the servo tray in the
cabin. Like the rudder servo, the throttle servo is installed upside
❑
3) The engine mounting bolt holes are now drilled through the
two mount arms. These four holes should be clearance holes for
the bolts you intend to use. For example, using the Saito 1.00
engine shown here, we used 8-32 x 1-1/4” socket head bolts. For
8-32 bolts we used a #19 (.166” dia,) bit to drill the proper
clearance holes. If you are careful, it may be possible to drill these
holes by hand, using a power drill. However, using a drill press to
drill these holes ensures that they are correctly placed and drilled
truly perpendicular to the motor mount arms.
❑
4) The 3-1/2” square piece of plywood used in the earlier
steps has now become a very accurate pattern that is used to
accurately locate the four required motor mount holes onto the
fuselage firewall. Hold the pattern against the firewall and line-up
its horizontal and vertical centerlines with those on the firewall.
Note that the horizontal and vertical locating lines on the firewall
appear to be offset and they are. This is because these two lines
take into consideration the 2
O
of right thrust and the 2
O
of down
thrust built into the fuselage.
Securely tape or hold the pattern firmly in place with the
centerlines aligned with those on the firewall. Use a pencil to
clearly mark the four hole locations onto the firewall. Remove the
pattern and use a 7/32” dia. bit and a power drill to drill the four
mounting holes completely through the firewall at the marks just
made.
❑
5) From the kit contents, locate Bag 18, Sub Bag A. The four
8-32 blind mounting nuts are now installed and glued into the
backside of the firewall. This can be made easier by first threading
the backside of one of the blind nuts partially onto the end of a
lightly tapered 14” length of 1/8” dia. dowel. Apply a little 30-minute
epoxy to the splined face and barrel of the blind nut. Feed the
dowel through the bottom wing saddle, to the firewall and then into
one of the drilled holes. From the front side of the firewall, insert
one of the 8-32 bolts and washers through the plywood pattern and