Page 8
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Construction Manual
Both F3’s should be perfectly centered on F1 and we recommend
using epoxy for this step. Clamp the pieces together and allow
them to cure.
Step 43 - Center Section (firewall)
Dry fit the firewall into place on the
front of the center section. Lightly sand
as necessary to obtain a good, firm fit.
Now remove the firewall, mix up a bit
of epoxy and glue the firewall to the
center section.
Be sure to form a bit of fillet between
the side walls (R1s) and the firewall to
add additional strength.
This photo shows mounting of the
electric firewall.
Step 44 - Cowl Assembly (frame)
Set the Comet assembly
aside for these next few
steps as we’ll assemble
the cowling.
Locate CB1 and the four
CTs from LP3. Place CB1
on your work surface
then glue each CT into
the side slots on CB1.
Each CT needs to be at a
perfect right angle and seated firmly into the slots.
Step 45 - Cowl Assembly (frame)
Locate CB2 from LP3. Place the CB1 on
your work surface, with the tabs resting
on the work surface (like a little table).
Press CB2 in place making sure it’s held
at a perfect 90° to CB1 (perpendicular).
Glue the 2 pieces together to form the
frame of the cowl.
Step 46 - Cowl Assembly (forming)
This step will require a lot of pieces,
glued in place to the cowling frame
in pairs. These are the C1-C13
pieces located on BP5 and BP4. It is
recommended to only cut a pair of
these pieces out at one time, starting
with C1.
Position both C1’s as shown here
without glue first. They should butt
up against the vertical spine (CB2)
and be centered on the base (CB1).
When you see how they should line
up, remove them, apply glue and
attach them to the cowl framework.
Step 47 - Cowl Assembly (frame)
Now using the same technique as you did in the last step, slowly
work your way up the framework by attaching the C2 pieces, then
the C3 pieces, etc. Make sure that
everything remains straight as you
don’t want to inadvertently put a
bend in the spine (CB2).
Once the C13s are in place, locate
CR from LP3. This will be glued to
the top of the C13’s and the CR’s
precut slots will fit into the tabs
extending from the spine (CB2).
Note that there is an etched ring on
CR that designates the front face of
the cowl. This circle should be visible
when it is glued in place as it’s used as a reference when sanding
the cowl to shape.
Step 48 - Cowl Assembly (mounting)
Once the glue has cured on the cowl, it’s time to shape it. The
center section of the Comet and
the cowl’s plywood frame will be
your guide in sanding. Slip the
cowl onto the front of the Comet
with the tabs sliding into the slots
on the side of the center section.
Make sure that the cowl rests firmly
against the firewall. Lightly sand as
necessary to get a good fit.
Now, to hold the cowl in position, drill into the holes in each cowl
mounting tab using a 1/16” bit. Make the holes about a 1/2” deep.
Using 4 of the supplied 2-56 x 3/4” self tapping screws, attach the
cowl to the Comet.
Step 49 - Cowl Assembly (sanding)
Sanding starts with the rear part of the cowl, the rectangular section.
Use a sanding block with 80 grit paper to sand the oversized sides
of the cowl so they’re flush with the fuselage (left and right). The
top and bottom should be sanded so they’re 1/16” oversized so
they will be flush with sheeting that will be installed later. Tape a
small piece of leftover 1/16th sheet to the top and bottom of the
firewall to give you a visual reference when sanding.
When finished, the rear of the cowl should have 4 flat sections that
line up with the sides of the center section.
Step 50 - Cowl Assembly (sanding)
Now the cowl can be removed from the Comet as it will make
it easier to form the front of the cowl. As you may recall, we
referenced a circle etched into the CR (front face) of the cowl.
Using your sanding block, take a bit of time to work on the shape
of the cowl, sanding down to
the circle.
Step 51 - Cowl Assembly
(sanding)
With the rear and front surfaces
shaped, now finish the cowl
by gently sanding the center
section to blend the round front
into the square rear. When the
rough shape has been reached,
switch to 150 grit paper to sand
the cowl to it’s final shape.
