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FUSELAGE CONSTRUCTION
Fuselage Sub-Assemblies
1a.
Mark the vertical centerline and thrust line on the F-1 firewall using the plan cross-section and tick marks on the firewall.
b.
Check the width of your engine and determine the spacing needed between the motor mounts. Using the lines on the
firewall, locate the mounts and mark the location of the four mounting holes on the firewall. Drill a 11/64" hole at each mark.
c.
Bolt the engine mounts loosely to the firewall with four 6-32 x3/4" bolts and 6-32 blind nuts. Double check the location and
spacing of the mounts. Tighten the bolts until the prongs of the blind nuts are started in the wood and holding. Remove the
motor mounts from the firewall and seat the blind nuts with a hammer.
d.
Lay former F-1A (sheet10) on the backside of the firewall. Mark and cut out around the top two blind nuts and glue it to the
back of the firewall. Apply Thick CA or epoxy over the blind nuts to hold them in place. Do not get glue in the threads.
2a.
Mount the engine mounts back onto the firewall. Using the side view plan as a
guide, locate the engine on the mounts so the propeller will clear the front of the
cowl by 1/8". Carefully mark the location of the engine mounting holes onto the
mounts.
b.
Remove the engine mounts from the firewall for drilling of the clearance holes for
your engine mounting bolts. It’s best to lock the mount in a vise and drill the holes
with a drill press, if you have access to one. Note: Because some .40-.46 engines
use 4-40 mounting bolts and some use 6-32 bolts, we do not supply the bolts and
lock nuts for mounting your engine to the mounts.
c.
Next, bolt the engine mounts back onto the firewall, and then the engine to the
mounts. Assemble one of the supplied Pushrod Connector assemblies in the
engine’s throttle arm. Now determine the best location for the throttle pushrod to
pass through the firewall and line up with the pushrod connector. (in the case of
the Irvine .46 in the photo, that spot is right above the leg of the engine mount -
your’s may be a little different). Once determined, mark the location and drill a
9/64" dia. hole through the firewall for the pushrod.
3a.
Glue the tailwheel mount (sheet.26) to the balsa fuselage bottom rear (sheet 19).
b.
Draw a center line on the fuselage
bottom rear and mark the location of the
mounting holes for the tailwheel leaf-
spring. Drill the holes with a 5/32" bit.
Mount the leafspring to the fuselage with
the 6-32 x1/2" machine screws and
square nuts provided.